[ttml2] synchronize with final FPWD rendition ttml2-WD-20150212-FPWD
authorGlenn Adams <glenn@skynav.com>
Wed, 18 Feb 2015 17:23:08 -0700
changeset 876 57da61404d8d
parent 875 1e95a6890402
child 877 56405bd47b77
[ttml2] synchronize with final FPWD rendition
ttml2/spec/FPWD-ttml2-201502XX.zip
ttml2/spec/entitiesfpwd.dtd
ttml2/spec/ttml2-20150114-pre-fpwd-review-1.html
ttml2/spec/ttml2.html
Binary file ttml2/spec/FPWD-ttml2-201502XX.zip has changed
--- a/ttml2/spec/entitiesfpwd.dtd	Mon Feb 16 21:07:13 2015 -0800
+++ b/ttml2/spec/entitiesfpwd.dtd	Wed Feb 18 17:23:08 2015 -0700
@@ -6,8 +6,8 @@
 <!ENTITY draft.year "2015">
 <!ENTITY draft.month "February">
 <!ENTITY draft.mm "02">
-<!ENTITY draft.day "10">
-<!ENTITY draft.dd "10">
+<!ENTITY draft.day "12">
+<!ENTITY draft.dd "12">
 
 <!ENTITY draft.date "&draft.year;&draft.mm;&draft.dd;">
 
--- a/ttml2/spec/ttml2-20150114-pre-fpwd-review-1.html	Mon Feb 16 21:07:13 2015 -0800
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,10430 +0,0 @@
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-  PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
-<html lang="en-us"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Timed Text Markup Language 2 (TTML2) -- (Editor's copy)</title><style type="text/css">
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-</style><link rel="stylesheet" type="text/css" href="https://www.w3.org/StyleSheets/TR/W3C-ED.css"></head><body>Last Modified: $Date: 2015/01/14 16:45:15 $<div id="revisions"></div><div class="head">
-<h1><a id="title"></a>Timed Text Markup Language 2 (TTML2)</h1>
-<h2><a id="w3c-doctype"></a>Editors' copy $Date: 2015/01/14 16:45:15 $ @@ @@@@ @@@@</h2><dl><dt>This version:</dt><dd>
-<a href="ttml2.html">ttml2.html</a>
-</dd><dt>Latest version:</dt><dd><a href="https://dvcs.w3.org/hg/ttml/raw-file/default/ttml2/spec/ttml2.html?content-type=text/html;charset=utf-8">https://dvcs.w3.org/hg/ttml/raw-file/default/ttml2/spec/ttml2.html?content-type=text/html;charset=utf-8</a></dd><dt>Previous version:</dt><dd>
-<a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/">http://www.w3.org/TR/2013/REC-ttml1-20130924/</a>
-</dd><dt>Editor:</dt><dd>Glenn Adams, Skynav, Inc.</dd><dt>Contributing Authors:</dt><dd>Mike Dolan, Invited Expert</dd><dd>Sean Hayes, Microsoft</dd><dd>Frans de Jong, European Broadcasting Union</dd><dd>Pierre-Anthony Lemieux, MovieLabs</dd><dd>Nigel Megitt, British Broadcasting Corporation</dd><dd>Dave Singer, Apple Computer</dd><dd>Jerry Smith, Microsoft</dd><dd>Andreas Tai, Invited Expert</dd></dl><p>Please refer to the <a href="https://dvcs.w3.org/hg/ttml/raw-file/default/ttml10/spec/ttml-issues.html">errata</a> for this document, which may
-      include normative corrections.</p><p>See also <a href="http://www.w3.org/2003/03/Translations/byTechnology?technology=ttml2"><strong>translations</strong></a>.</p><p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a>&nbsp;©&nbsp;@@@@&nbsp;<a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>, <a href="http://ev.buaa.edu.cn/">Beihang</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p></div><hr><div>
-<h2><a id="abstract"></a>Abstract</h2><p>This document specifies the Timed Text Markup Language (TTML), Version 2, also known as TTML2,
-in terms of a vocabulary and semantics thereof.</p><p>The Timed Text Markup Language is a content type that represents
-timed text media for the purpose of interchange among authoring
-systems. Timed text is textual information that is intrinsically or
-extrinsically associated with timing information.</p><p>It is intended to be used
-for the purpose of transcoding or exchanging timed text information
-among legacy distribution content formats presently in use for
-subtitling and captioning functions.</p><p>In addition to being used for interchange among legacy distribution content
-formats, TTML Content may be used directly as a distribution format,
-for example, providing a standard content format to reference from a <code>&lt;track&gt;</code>
-element in an HTML5 document, or a <code>&lt;text&gt;</code> or 
-<code>&lt;textstream&gt;</code> media element in a <a href="#smil3">[SMIL 3.0]</a> document.</p></div><div>
-<h2><a id="status"></a>Status of this Document</h2><p><strong>This document is an editor's copy that has
-        no official standing.</strong></p><p></p></div><div class="toc">
-<h2><a id="contents"></a>Table of Contents</h2><p class="toc">1 <a href="#intro">Introduction</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;1.1 <a href="#model">System Model</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;1.2 <a href="#example">Document Example</a><br>
-2 <a href="#definitions">Definitions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;2.1 <a href="#acronyms">Acronyms</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;2.2 <a href="#terms">Terminology</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;2.3 <a href="#conventions">Documentation Conventions</a><br>
-3 <a href="#conformance">Conformance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;3.1 <a href="#conformance-content">Document Conformance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;3.2 <a href="#conformance-processor">Processor Conformance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.1 <a href="#conformance-generic-processor">Generic Processor Conformance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.2 <a href="#conformance-transformation-processor">Transformation Processor Conformance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.3 <a href="#conformance-presentation-processor">Presentation Processor Conformance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;3.3 <a href="#claims">Claims</a><br>
-4 <a href="#doctypes">Document Types</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;4.1 <a href="#ttml-content-doctype">TTML Content Document Type</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;4.2 <a href="#ttml-intermediate-doctype">TTML Intermediate Document Type</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;4.3 <a href="#ttml-profile-doctype">TTML Profile Document Type</a><br>
-5 <a href="#vocabulary">Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;5.1 <a href="#vocabulary-namespaces">Namespaces</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;5.2 <a href="#vocabulary-profiling">Profiling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.1 <a href="#vocabulary-profile-introduction">Introduction</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.2 <a href="#semantics-profile-examples">Profile Examples</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.3 <a href="#vocabulary-profile-designators">Profile Designators</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.3.1 <a href="#vocabulary-profile-standard-designators">Standard Designators</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.4 <a href="#semantics-profile-semantics">Profile Semantics</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.4.1 <a href="#semantics-profile-state">Profile State Object Concepts</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.4.2 <a href="#semantics-content-profile-processing">Content Profile Semantics</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.2.4.3 <a href="#semantics-processor-profile-processing">Processor Profile Semantics</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;5.3 <a href="#vocabulary-overview">Catalog</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.3.1 <a href="#core-vocabulary-overview">Core Catalog</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.3.2 <a href="#extension-vocabulary-overview">Extension Catalog</a><br>
-6 <a href="#profile">Profile</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;6.1 <a href="#profile-element-vocabulary">Profile Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.1.1 <a href="#profile-vocabulary-profile">ttp:profile</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.1.2 <a href="#profile-vocabulary-features">ttp:features</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.1.3 <a href="#profile-vocabulary-feature">ttp:feature</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.1.4 <a href="#profile-vocabulary-extensions">ttp:extensions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.1.5 <a href="#profile-vocabulary-extension">ttp:extension</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;6.2 <a href="#profile-attribute-vocabulary">Profile Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.1 <a href="#profile-attribute-contentProfiles">ttp:contentProfiles</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.2 <a href="#profile-attribute-contentProfileCombination">ttp:contentProfileCombination</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.3 <a href="#profile-attribute-inferProcessorProfileMethod">ttp:inferProcessorProfileMethod</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.4 <a href="#profile-attribute-inferProcessorProfileSource">ttp:inferProcessorProfileSource</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.5 <a href="#profile-attribute-permitFeatureNarrowing">ttp:permitFeatureNarrowing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.6 <a href="#profile-attribute-permitFeatureWidening">ttp:permitFeatureWidening</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.7 <a href="#profile-attribute-profile">ttp:profile</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.8 <a href="#profile-attribute-processorProfiles">ttp:processorProfiles</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.9 <a href="#profile-attribute-processorProfileCombination">ttp:processorProfileCombination</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.10 <a href="#profile-attribute-validation">ttp:validation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.11 <a href="#profile-attribute-validationAction">ttp:validationAction</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.2.12 <a href="#profile-attribute-version">ttp:version</a><br>
-7 <a href="#parameter">Parameter</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;7.1 <a href="#parameter-element-vocabulary">Parameter Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;7.2 <a href="#parameter-attribute-vocabulary">Parameter Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.1 <a href="#parameter-attribute-cellResolution">ttp:cellResolution</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.2 <a href="#parameter-attribute-clockMode">ttp:clockMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.3 <a href="#parameter-attribute-dropMode">ttp:dropMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.4 <a href="#parameter-attribute-frameRate">ttp:frameRate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.5 <a href="#parameter-attribute-frameRateMultiplier">ttp:frameRateMultiplier</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.6 <a href="#parameter-attribute-markerMode">ttp:markerMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.7 <a href="#parameter-attribute-mediaDuration">ttp:mediaDuration</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.8 <a href="#parameter-attribute-mediaOffset">ttp:mediaOffset</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.9 <a href="#parameter-attribute-pixelAspectRatio">ttp:pixelAspectRatio</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.10 <a href="#parameter-attribute-storageAspectRatio">ttp:storageAspectRatio</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.11 <a href="#parameter-attribute-subFrameRate">ttp:subFrameRate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.12 <a href="#parameter-attribute-tickRate">ttp:tickRate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7.2.13 <a href="#parameter-attribute-timeBase">ttp:timeBase</a><br>
-8 <a href="#content">Content</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;8.1 <a href="#content-element-vocabulary">Content Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.1 <a href="#document-structure-vocabulary-tt">tt</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.2 <a href="#document-structure-vocabulary-head">head</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.3 <a href="#document-structure-vocabulary-body">body</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.4 <a href="#content-vocabulary-div">div</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.5 <a href="#content-vocabulary-p">p</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.6 <a href="#content-vocabulary-span">span</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.1.7 <a href="#content-vocabulary-br">br</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;8.2 <a href="#content-attribute-vocabulary">Content Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.1 <a href="#content-attribute-condition">condition</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.2 <a href="#content-attribute-xlink-arcrole">xlink:arcrole</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.3 <a href="#content-attribute-xlink-href">xlink:href</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.4 <a href="#content-attribute-xlink-role">xlink:role</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.5 <a href="#content-attribute-xlink-show">xlink:show</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.6 <a href="#content-attribute-xlink-title">xlink:title</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.7 <a href="#content-attribute-xml-id">xml:id</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.8 <a href="#content-attribute-xml-lang">xml:lang</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.2.9 <a href="#content-attribute-xml-space">xml:space</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;8.3 <a href="#content-value-expressions">Content Value Expressions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.1 <a href="#content-value-arguments">&lt;arguments&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.2 <a href="#content-value-bound-parameter">&lt;bound-parameter&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.3 <a href="#content-value-condition">&lt;condition&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.4 <a href="#content-value-condition-function">&lt;condition-function&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.5 <a href="#content-value-expression">&lt;expression&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.6 <a href="#content-value-media-function">&lt;media-function&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.7 <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.8 <a href="#content-value-parameter-function">&lt;parameter-function&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8.3.9 <a href="#content-value-supports-function">&lt;supports-function&gt;</a><br>
-9 <a href="#embedded-content">Embedded Content</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;9.1 <a href="#embedded-content-element-vocabulary">Embedded Content Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.1 <a href="#embedded-content-vocabulary-audio">audio</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.2 <a href="#embedded-content-vocabulary-chunk">chunk</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.3 <a href="#embedded-content-vocabulary-data">data</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.4 <a href="#embedded-content-vocabulary-font">font</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.5 <a href="#embedded-content-vocabulary-image">image</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.6 <a href="#embedded-content-vocabulary-resources">resources</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.1.7 <a href="#embedded-content-vocabulary-source">source</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;9.2 <a href="#embedded-content-attribute-vocabulary">Embedded Content Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.2.1 <a href="#embedded-content-attribute-encoding">encoding</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.2.2 <a href="#embedded-content-attribute-format">format</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.2.3 <a href="#embedded-content-attribute-src">src</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.2.4 <a href="#embedded-content-attribute-type">type</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;9.3 <a href="#embedded-content-value-expressions">Embedded Content Value Expressions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.1 <a href="#embedded-content-value-audio">&lt;audio&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.2 <a href="#embedded-content-value-audio-format">&lt;audio-format&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.3 <a href="#embedded-content-value-data">&lt;data&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.4 <a href="#embedded-content-value-data-format">&lt;data-format&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.5 <a href="#embedded-content-value-font">&lt;font&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.6 <a href="#embedded-content-value-font-format">&lt;font-format&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.7 <a href="#embedded-content-value-image">&lt;image&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.8 <a href="#embedded-content-value-image-format">&lt;image-format&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9.3.9 <a href="#embedded-content-value-unicode-range">&lt;unicode-range&gt;</a><br>
-10 <a href="#styling">Styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;10.1 <a href="#styling-element-vocabulary">Styling Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.1.1 <a href="#styling-vocabulary-initial">initial</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.1.2 <a href="#styling-vocabulary-style">style</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.1.3 <a href="#styling-vocabulary-styling">styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;10.2 <a href="#styling-attribute-vocabulary">Styling Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.1 <a href="#style-attribute-style">style</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.2 <a href="#style-attribute-backgroundColor">tts:backgroundColor</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.3 <a href="#style-attribute-backgroundImage">tts:backgroundImage</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.4 <a href="#style-attribute-backgroundPosition">tts:backgroundPosition</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.5 <a href="#style-attribute-backgroundRepeat">tts:backgroundRepeat</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.6 <a href="#style-attribute-border">tts:border</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.7 <a href="#style-attribute-color">tts:color</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.8 <a href="#style-attribute-direction">tts:direction</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.9 <a href="#style-attribute-display">tts:display</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.10 <a href="#style-attribute-displayAlign">tts:displayAlign</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.11 <a href="#style-attribute-extent">tts:extent</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.12 <a href="#style-attribute-fontFamily">tts:fontFamily</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.13 <a href="#style-attribute-fontKerning">tts:fontKerning</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.14 <a href="#style-attribute-fontSelectionStrategy">tts:fontSelectionStrategy</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.15 <a href="#style-attribute-fontShear">tts:fontShear</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.16 <a href="#style-attribute-fontSize">tts:fontSize</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.17 <a href="#style-attribute-fontStyle">tts:fontStyle</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.18 <a href="#style-attribute-fontVariantPosition">tts:fontVariantPosition</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.19 <a href="#style-attribute-fontWeight">tts:fontWeight</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.20 <a href="#style-attribute-height">tts:height</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.21 <a href="#style-attribute-letterSpacing">tts:letterSpacing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.22 <a href="#style-attribute-lineHeight">tts:lineHeight</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.23 <a href="#style-attribute-opacity">tts:opacity</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.24 <a href="#style-attribute-origin">tts:origin</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.25 <a href="#style-attribute-overflow">tts:overflow</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.26 <a href="#style-attribute-padding">tts:padding</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.27 <a href="#style-attribute-position">tts:position</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.28 <a href="#style-attribute-ruby">tts:ruby</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.29 <a href="#style-attribute-rubyAlign">tts:rubyAlign</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.30 <a href="#style-attribute-rubyOffset">tts:rubyOffset</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.31 <a href="#style-attribute-rubyPosition">tts:rubyPosition</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.32 <a href="#style-attribute-showBackground">tts:showBackground</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.33 <a href="#style-attribute-textAlign">tts:textAlign</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.34 <a href="#style-attribute-textCombine">tts:textCombine</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.35 <a href="#style-attribute-textDecoration">tts:textDecoration</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.36 <a href="#style-attribute-textEmphasis">tts:textEmphasis</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.37 <a href="#style-attribute-textOrientation">tts:textOrientation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.38 <a href="#style-attribute-textOutline">tts:textOutline</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.39 <a href="#style-attribute-textShadow">tts:textShadow</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.40 <a href="#style-attribute-unicodeBidi">tts:unicodeBidi</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.41 <a href="#style-attribute-visibility">tts:visibility</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.42 <a href="#style-attribute-width">tts:width</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.43 <a href="#style-attribute-wrapOption">tts:wrapOption</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.44 <a href="#style-attribute-writingMode">tts:writingMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2.45 <a href="#style-attribute-zIndex">tts:zIndex</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;10.3 <a href="#styling-style-value-expressions">Styling Value Expressions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.1 <a href="#style-value-alpha">&lt;alpha&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.2 <a href="#style-value-borderColor">&lt;borderColor&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.3 <a href="#style-value-borderStyle">&lt;borderStyle&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.4 <a href="#style-value-borderWidth">&lt;borderWidth&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.5 <a href="#style-value-color">&lt;color&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.6 <a href="#style-value-digit">&lt;digit&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.7 <a href="#style-value-emphasisColor">&lt;emphasisColor&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.8 <a href="#style-value-emphasisStyle">&lt;emphasisStyle&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.9 <a href="#style-value-emphasisPosition">&lt;emphasisPosition&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.10 <a href="#style-value-familyName">&lt;familyName&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.11 <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.12 <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.13 <a href="#style-value-integer">&lt;integer&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.14 <a href="#style-value-length">&lt;length&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.15 <a href="#style-value-measure">&lt;measure&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.16 <a href="#style-value-namedColor">&lt;namedColor&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.17 <a href="#style-value-non-negative-integer">&lt;non-negative-integer&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.18 <a href="#style-value-number">&lt;number&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.19 <a href="#style-value-percentage">&lt;percentage&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.20 <a href="#style-value-position">&lt;position&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.3.21 <a href="#style-value-shadow">&lt;shadow&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;10.4 <a href="#semantics-styling">Styling Semantics</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.1 <a href="#semantics-style-association">Style Association</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.1.1 <a href="#semantics-style-association-inline">Inline Styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.1.2 <a href="#semantics-style-association-referential">Referential Styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.1.3 <a href="#semantics-style-association-chained-referential">Chained Referential Styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.1.4 <a href="#semantics-style-association-nested">Nested Styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.2 <a href="#semantics-style-inheritance">Style Inheritance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.2.1 <a href="#semantics-style-inheritance-content">Content Style Inheritance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.2.2 <a href="#semantics-style-inheritance-region">Region Style Inheritance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.2.3 <a href="#semantics-style-inheritance-root">Root Style Inheritance</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.3 <a href="#semantics-style-resolution-value-categories">Style Resolution Value Categories</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.3.1 <a href="#semantics-style-resolved-value-category-specified">Specified Values</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.3.2 <a href="#semantics-style-resolved-value-category-computed">Computed Values</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.3.3 <a href="#semantics-style-resolved-value-category-actual">Actual Values</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.4 <a href="#semantics-style-resolution-processing">Style Resolution Processing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.4.1 <a href="#semantics-style-resolution-processing-definitions">Conceptual Definitions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.4.2 <a href="#semantics-style-resolution-processing-sss">Specified Style Set Processing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.4.3 <a href="#semantics-style-resolution-processing-css">Computed Style Set Processing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.4.4 <a href="#semantics-style-resolution-process-overall">Style Resolution Process</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.4.5 <a href="#semantics-style-automatic-measure-calculation">Automatic Measure Calculation</a><br>
-11 <a href="#layout">Layout</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;11.1 <a href="#layout-element-vocabulary">Layout Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.1.1 <a href="#layout-vocabulary-layout">layout</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.1.2 <a href="#layout-vocabulary-region">region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;11.2 <a href="#layout-attribute-vocabulary">Layout Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.2.1 <a href="#layout-attribute-region">region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;11.3 <a href="#semantics-layout">Layout Semantics</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.1 <a href="#semantics-region-layout">Region Layout and Presentation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.1.1 <a href="#semantics-default-region">Default Region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.1.2 <a href="#semantics-inline-regions">Inline Regions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.1.3 <a href="#semantics-region-layout-step-1">Intermediate Synchronic Document Construction</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.1.4 <a href="#semantics-region-layout-step-2">Synchronic Flow Processing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.1.5 <a href="#semantics-region-layout-example">Elaborated Example (Non-Normative)</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11.3.2 <a href="#semantics-line-layout">Line Layout</a><br>
-12 <a href="#timing">Timing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;12.1 <a href="#timing-element-vocabulary">Timing Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;12.2 <a href="#timing-attribute-vocabulary">Timing Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;12.2.1 <a href="#timing-attribute-begin">begin</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;12.2.2 <a href="#timing-attribute-dur">dur</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;12.2.3 <a href="#timing-attribute-end">end</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;12.2.4 <a href="#timing-attribute-timeContainer">timeContainer</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;12.3 <a href="#timing-time-value-expressions">Time Value Expressions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;12.3.1 <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;12.4 <a href="#semantics-timing">Timing Semantics</a><br>
-13 <a href="#animation">Animation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;13.1 <a href="#animation-element-vocabulary">Animation Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.1.1 <a href="#animation-vocabulary-animate">animate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.1.2 <a href="#animation-vocabulary-animation">animation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.1.3 <a href="#animation-vocabulary-set">set</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;13.2 <a href="#animation-attribute-vocabulary">Animation Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.2.1 <a href="#animation-attribute-animate">animate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;13.3 <a href="#animation-value-expressions">Animation Value Expressions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.1 <a href="#animation-value-animationValue">&lt;animationValue&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.2 <a href="#animation-value-animationValueList">&lt;animationValueList&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.3 <a href="#animation-value-calcMode">&lt;calcMode&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.4 <a href="#animation-value-fill">&lt;fill&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.5 <a href="#animation-value-keySplines">&lt;keySplines&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.6 <a href="#animation-value-keyTimes">&lt;keyTimes&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;13.3.7 <a href="#animation-value-repeatCount">&lt;repeatCount&gt;</a><br>
-14 <a href="#metadata">Metadata</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;14.1 <a href="#metadata-element-vocabulary">Metadata Element Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.1 <a href="#metadata-vocabulary-metadata">metadata</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.2 <a href="#metadata-vocabulary-actor">ttm:actor</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.3 <a href="#metadata-vocabulary-agent">ttm:agent</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.4 <a href="#metadata-vocabulary-copyright">ttm:copyright</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.5 <a href="#metadata-vocabulary-desc">ttm:desc</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.6 <a href="#metadata-vocabulary-item">ttm:item</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.7 <a href="#metadata-vocabulary-name">ttm:name</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.1.8 <a href="#metadata-vocabulary-title">ttm:title</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;14.2 <a href="#metadata-attribute-vocabulary">Metadata Attribute Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.2.1 <a href="#metadata-attribute-agent">ttm:agent</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.2.2 <a href="#metadata-attribute-role">ttm:role</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;14.3 <a href="#metadata-value-expressions">Metadata Value Expressions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.3.1 <a href="#metadata-value-item-name">&lt;item-name&gt;</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;14.3.2 <a href="#metadata-value-named-item">&lt;named-item&gt;</a><br>
-</p>
-<h3><a id="appendices"></a>Appendices</h3><p class="toc">A <a href="#concrete-encoding">Concrete Encoding</a><br>
-B <a href="#reduced-infoset">Reduced XML Infoset</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;B.1 <a href="#reduced-infoset-document">Document Information Item</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;B.2 <a href="#reduced-infoset-element">Element Information Item</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;B.3 <a href="#reduced-infoset-attribute">Attribute Information Item</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;B.4 <a href="#reduced-infoset-character">Character Information Item</a><br>
-C <a href="#schemas">Schemas</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;C.1 <a href="#ttml-schema-rnc">Relax NG Compact (RNC) Schema</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;C.2 <a href="#ttml-schema-xsd">XML Schema Definition (XSD) Schema</a><br>
-D <a href="#media-types-registration">Media Type Registration</a><br>
-E <a href="#features">Features</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;E.1 <a href="#feature-designations">Feature Designations</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.1 <a href="#feature-animation">#animation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.2 <a href="#feature-backgroundColor">#backgroundColor</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.3 <a href="#feature-backgroundColor-block">#backgroundColor-block</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.4 <a href="#feature-backgroundColor-inline">#backgroundColor-inline</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.5 <a href="#feature-backgroundColor-region">#backgroundColor-region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.6 <a href="#feature-bidi">#bidi</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.7 <a href="#feature-border">#border</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.8 <a href="#feature-cellResolution">#cellResolution</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.9 <a href="#feature-clockMode">#clockMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.10 <a href="#feature-clockMode-gps">#clockMode-gps</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.11 <a href="#feature-clockMode-local">#clockMode-local</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.12 <a href="#feature-clockMode-utc">#clockMode-utc</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.13 <a href="#feature-color">#color</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.14 <a href="#feature-content">#content</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.15 <a href="#feature-core">#core</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.16 <a href="#feature-direction">#direction</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.17 <a href="#feature-display">#display</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.18 <a href="#feature-display-block">#display-block</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.19 <a href="#feature-display-inline">#display-inline</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.20 <a href="#feature-display-region">#display-region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.21 <a href="#feature-displayAlign">#displayAlign</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.22 <a href="#feature-dropMode">#dropMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.23 <a href="#feature-dropMode-dropNTSC">#dropMode-dropNTSC</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.24 <a href="#feature-dropMode-dropPAL">#dropMode-dropPAL</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.25 <a href="#feature-dropMode-nonDrop">#dropMode-nonDrop</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.26 <a href="#feature-extent">#extent</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.27 <a href="#feature-extent-region">#extent-region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.28 <a href="#feature-extent-root">#extent-root</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.29 <a href="#feature-fontFamily">#fontFamily</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.30 <a href="#feature-fontFamily-generic">#fontFamily-generic</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.31 <a href="#feature-fontFamily-non-generic">#fontFamily-non-generic</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.32 <a href="#feature-fontSize">#fontSize</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.33 <a href="#feature-fontSize-anamorphic">#fontSize-anamorphic</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.34 <a href="#feature-fontSize-isomorphic">#fontSize-isomorphic</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.35 <a href="#feature-fontStyle">#fontStyle</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.36 <a href="#feature-fontStyle-italic">#fontStyle-italic</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.37 <a href="#feature-fontStyle-oblique">#fontStyle-oblique</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.38 <a href="#feature-fontWeight">#fontWeight</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.39 <a href="#feature-fontWeight-bold">#fontWeight-bold</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.40 <a href="#feature-frameRate">#frameRate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.41 <a href="#feature-frameRateMultiplier">#frameRateMultiplier</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.42 <a href="#feature-layout">#layout</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.43 <a href="#feature-length">#length</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.44 <a href="#feature-length-cell">#length-cell</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.45 <a href="#feature-length-em">#length-em</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.46 <a href="#feature-length-integer">#length-integer</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.47 <a href="#feature-length-negative">#length-negative</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.48 <a href="#feature-length-percentage">#length-percentage</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.49 <a href="#feature-length-pixel">#length-pixel</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.50 <a href="#feature-length-positive">#length-positive</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.51 <a href="#feature-length-real">#length-real</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.52 <a href="#feature-lineBreak-uax14">#lineBreak-uax14</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.53 <a href="#feature-lineHeight">#lineHeight</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.54 <a href="#feature-markerMode">#markerMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.55 <a href="#feature-markerMode-continuous">#markerMode-continuous</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.56 <a href="#feature-markerMode-discontinuous">#markerMode-discontinuous</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.57 <a href="#feature-metadata">#metadata</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.58 <a href="#feature-nested-div">#nested-div</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.59 <a href="#feature-nested-span">#nested-span</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.60 <a href="#feature-opacity">#opacity</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.61 <a href="#feature-origin">#origin</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.62 <a href="#feature-overflow">#overflow</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.63 <a href="#feature-overflow-visible">#overflow-visible</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.64 <a href="#feature-padding">#padding</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.65 <a href="#feature-padding-1">#padding-1</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.66 <a href="#feature-padding-2">#padding-2</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.67 <a href="#feature-padding-3">#padding-3</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.68 <a href="#feature-padding-4">#padding-4</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.69 <a href="#feature-pixelAspectRatio">#pixelAspectRatio</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.70 <a href="#feature-presentation">#presentation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.71 <a href="#feature-profile">#profile</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.72 <a href="#feature-showBackground">#showBackground</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.73 <a href="#feature-structure">#structure</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.74 <a href="#feature-styling">#styling</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.75 <a href="#feature-styling-chained">#styling-chained</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.76 <a href="#feature-styling-inheritance-content">#styling-inheritance-content</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.77 <a href="#feature-styling-inheritance-region">#styling-inheritance-region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.78 <a href="#feature-styling-inline">#styling-inline</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.79 <a href="#feature-styling-nested">#styling-nested</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.80 <a href="#feature-styling-referential">#styling-referential</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.81 <a href="#feature-subFrameRate">#subFrameRate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.82 <a href="#feature-textAlign">#textAlign</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.83 <a href="#feature-textAlign-absolute">#textAlign-absolute</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.84 <a href="#feature-textAlign-relative">#textAlign-relative</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.85 <a href="#feature-textDecoration">#textDecoration</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.86 <a href="#feature-textDecoration-over">#textDecoration-over</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.87 <a href="#feature-textDecoration-through">#textDecoration-through</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.88 <a href="#feature-textDecoration-under">#textDecoration-under</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.89 <a href="#feature-textOrientation">#textOrientation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.90 <a href="#feature-textOutline">#textOutline</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.91 <a href="#feature-textOutline-blurred">#textOutline-blurred</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.92 <a href="#feature-textOutline-unblurred">#textOutline-unblurred</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.93 <a href="#feature-tickRate">#tickRate</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.94 <a href="#feature-timeBase-clock">#timeBase-clock</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.95 <a href="#feature-timeBase-media">#timeBase-media</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.96 <a href="#feature-timeBase-smpte">#timeBase-smpte</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.97 <a href="#feature-timeContainer">#timeContainer</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.98 <a href="#feature-time-clock">#time-clock</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.99 <a href="#feature-time-clock-with-frames">#time-clock-with-frames</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.100 <a href="#feature-time-offset">#time-offset</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.101 <a href="#feature-time-offset-with-frames">#time-offset-with-frames</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.102 <a href="#feature-time-offset-with-ticks">#time-offset-with-ticks</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.103 <a href="#feature-timing">#timing</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.104 <a href="#feature-transformation">#transformation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.105 <a href="#feature-unicodeBidi">#unicodeBidi</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.106 <a href="#feature-version">#version</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.107 <a href="#feature-visibility">#visibility</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.108 <a href="#feature-visibility-block">#visibility-block</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.109 <a href="#feature-visibility-inline">#visibility-inline</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.110 <a href="#feature-visibility-region">#visibility-region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.111 <a href="#feature-wrapOption">#wrapOption</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.112 <a href="#feature-writingMode">#writingMode</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.113 <a href="#feature-writingMode-vertical">#writingMode-vertical</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.114 <a href="#feature-writingMode-horizontal">#writingMode-horizontal</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.115 <a href="#feature-writingMode-horizontal-lr">#writingMode-horizontal-lr</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.116 <a href="#feature-writingMode-horizontal-rl">#writingMode-horizontal-rl</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.1.117 <a href="#feature-zIndex">#zIndex</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;E.2 <a href="#feature-support">Feature Support</a><br>
-F <a href="#extensions">Extensions</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;F.1 <a href="#extension-designations">Extension Designations</a><br>
-G <a href="#standard-profiles">Standard Profiles</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;G.1 <a href="#profile-ttml2-full">TTML2 Full Profile</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;G.2 <a href="#profile-ttml2-presentation">TTML2 Presentation Profile</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;G.3 <a href="#profile-ttml2-transformation">TTML2 Transformation Profile</a><br>
-H <a href="#time-expression-semantics">Time Expression Semantics</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;H.1 <a href="#time-expression-semantics-clock">Clock Time Base</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;H.2 <a href="#time-expression-semantics-media">Media Time Base</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;H.3 <a href="#time-expression-semantics-smpte">SMPTE Time Base</a><br>
-I <a href="#isd">Intermediate Document Syntax</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;I.1 <a href="#isd-vocabulary">ISD Vocabulary</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I.1.1 <a href="#isd-vocabulary-sequence">isd:sequence</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I.1.2 <a href="#isd-vocabulary-isd">isd:isd</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I.1.3 <a href="#isd-vocabulary-css">isd:css</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I.1.4 <a href="#isd-vocabulary-region">isd:region</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;I.2 <a href="#isd-parameter-attribute-set">ISD Parameter Attribute Set</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;I.3 <a href="#isd-interchange">ISD Interchange</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;I.4 <a href="#isd-examples">ISD Examples</a><br>
-J <a href="#references">References</a><br>
-K <a href="#other-references">Other References</a> (Non-Normative)<br>
-L <a href="#requirements">Requirements</a> (Non-Normative)<br>
-M <a href="#derivation">Vocabulary Derivation</a> (Non-Normative)<br>
-&nbsp;&nbsp;&nbsp;&nbsp;M.1 <a href="#d3e37582">Element Derivation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;M.2 <a href="#d3e38099">Attribute Derivation</a><br>
-N <a href="#qa">QA Framework Compliance</a> (Non-Normative)<br>
-&nbsp;&nbsp;&nbsp;&nbsp;N.1 <a href="#d3e39092">Requirements</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;N.2 <a href="#d3e39256">Guidelines</a><br>
-O <a href="#streaming">Streaming TTML Content</a> (Non-Normative)<br>
-P <a href="#common-styling">Common Caption Style Examples</a> (Non-Normative)<br>
-&nbsp;&nbsp;&nbsp;&nbsp;P.1 <a href="#pop-on-example">Pop-On Caption Example</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;P.2 <a href="#roll-up-example">Roll-Up Caption Example</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;P.3 <a href="#paint-on-example">Paint-On Caption Example</a><br>
-Q <a href="#cea708-mapping">CEA708 Mapping Considerations</a> (Non-Normative)<br>
-R <a href="#acknowledgments">Acknowledgments</a> (Non-Normative)<br>
-</p></div><hr><div class="body"><div class="div1">
-<h2><a id="intro"></a>1 Introduction</h2><p><em>Unless specified otherwise, this section and its sub-sections are non-normative.</em></p><p>The Timed Text Markup Language (TTML), Version 2, also referred to as TTML2,
-provides a standardized representation of a particular subset of
-textual information with which stylistic, layout, and timing semantics are associated by
-an author or an authoring system for the purpose of interchange and processing.</p><p>TTML is expressly designed to meet only a limited set of requirements
-established by <a href="#ttaf1-req">[TTAF1-REQ]</a>, and summarized in <a href="#requirements"><b>L Requirements</b></a>. In particular, only those requirements which service the
-need of performing interchange with existing, legacy distribution systems are
-satisfied.</p><p>In addition to being used for interchange among legacy distribution content
-formats, TTML Content may be used directly as a distribution format, providing, for
-example, a standard content format to reference from a <code>&lt;track&gt;</code>
-element in an HTML5 document, or a <code>&lt;text&gt;</code> or 
-<code>&lt;textstream&gt;</code> media element in a <a href="#smil3">[SMIL 3.0]</a> document. Certain properties of TTML support
-streamability of content, as described in <a href="#streaming"><b>O Streaming TTML Content</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>While TTML is not expressly designed for direct (embedded) integration into an
-HTML or a SMIL document instance, such integration is not precluded.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>In some contexts of use, it may be appropriate to employ
-animated content to depict sign language representations of the same content
-as expressed by a Timed Text <a href="#terms-document-instance">document instance</a>. This use case is not
-explicitly addressed by TTML mechanisms, but may be addressed by some
-external multimedia integration technology, such as SMIL.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>In previous drafts of this specification, TTML was referred to as DFXP (Distribution
-Format Exchange Profile). This latter term is retained for historical reasons in
-certain contexts, such as profile names and designators, and the short name
-<code>ttaf1-dfxp</code> used in URLs to refer to this specification.</p></div><div class="div2">
-<h3><a id="model"></a>1.1 System Model</h3><p>Use of TTML is intended to function in a wider context of Timed Text
-Authoring and Distribution mechanisms that are based upon the system
-model depicted in <a href="#model-graphic"><b>Figure 1 – System Model</b></a>, wherein the Timed Text Markup Language
-serves as a bidirectional interchange format among a heterogeneous collection of
-authoring systems, and as a unidirectional interchange format to a
-heterogeneous collection of distribution formats after undergoing transcoding
-or compilation to the target distribution formats as required, and where one
-particular distribution format is TTML (labeled as "DFXP" in the figure).</p><a id="model-graphic"></a><table class="example-images"><caption>Figure 1 – System Model</caption><tbody><tr><td><img src="images/model.png" alt="System Model"></td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Revise System Model"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Revise System Model</b></td><td align="right" valign="top">2014-11-27</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Update system model diagram to reflect current and expected usage. Eliminate reference to DFXP.</td></tr></table></div><div class="div2">
-<h3><a id="example"></a>1.2 Document Example</h3><p>A TTML <a href="#terms-document-instance">document instance</a> consists of a <code>tt</code> document element that contains
-a header and a body, where the header specifies document level metadata, styling
-definitions and layout definitions, and the body specifies text content intermixed
-with references to style and layout information and inline styling and timing information.</p><a id="ttml-example-document-structure"></a><table class="example"><caption>Example Fragment – TTML Document Structure</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head&gt;
-    &lt;metadata/&gt;
-    &lt;styling/&gt;
-    &lt;layout/&gt;
-  &lt;/head&gt;
-  &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>Document level metadata may specify a document title, description,
-and copyright information. In addition, arbitrary metadata drawn from
-other namespaces may be specified.</p><a id="ttml-example-metadata"></a><table class="example"><caption>Example Fragment – TTML Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;metadata xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-  &lt;ttm:title&gt;Timed Text TTML Example&lt;/ttm:title&gt;
-  &lt;ttm:copyright&gt;The Authors (c) 2006&lt;/ttm:copyright&gt;
-&lt;/metadata&gt;
-</pre></div>
-</td></tr></tbody></table><p>Styling information may be specified in the form of style specification
-definitions that are referenced by layout and content information,
-specified inline with content information, or both.</p><p>In <a href="#ttml-example-styling"><b>Example Fragment – TTML Styling</b></a>, four style sets of specifications
-are defined, with one set serving as a collection of default styles.</p><a id="ttml-example-styling"></a><table class="example"><caption>Example Fragment – TTML Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;styling xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;!-- s1 specifies default color, font, and text alignment --&gt;
-  &lt;style xml:id="s1"
-    tts:color="white"
-    tts:fontFamily="proportionalSansSerif"
-    tts:fontSize="22px"
-    tts:textAlign="center"
-  /&gt;
-  &lt;!-- alternative using yellow text but otherwise the same as style s1 --&gt;
-  &lt;style xml:id="s2" style="s1" tts:color="yellow"/&gt;
-  &lt;!-- a style based on s1 but justified to the right --&gt;
-  &lt;style xml:id="s1Right" style="s1" tts:textAlign="end" /&gt;     
-  &lt;!-- a style based on s2 but justified to the left --&gt;
-  &lt;style xml:id="s2Left" style="s2" tts:textAlign="start" /&gt;
-&lt;/styling&gt;
-</pre></div>
-</td></tr></tbody></table><p>Layout information defines one or more regions into which content
-is intended to be presented. A region definition may reference one or
-more sets of style specifications in order to permit content flowed in the
-region to inherit from these styles.
-In <a href="#ttml-example-layout"><b>Example Fragment – TTML Layout</b></a>, the region definition makes
-reference to style specification <code>s1</code> augmented by specific inline
-styles which, together, allow content flowed into the region to inherit
-from the region's styles (in the case
-that a style is not already explicitly specified on content or inherited
-via the content hierarchy.)</p><a id="ttml-example-layout"></a><table class="example"><caption>Example Fragment – TTML Layout</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;layout xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;region xml:id="subtitleArea"
-    style="s1"
-    tts:extent="560px 62px"
-    tts:padding="5px 3px"
-    tts:backgroundColor="black"
-    tts:displayAlign="after"
-  /&gt;
-&lt;/layout&gt;  
-</pre></div>
-</td></tr></tbody></table><p>The content of a <a href="#terms-document-instance">document instance</a> is expressed in its
-body, which is organized in terms of block and inline text elements.
-The hierarchical organization of content elements serves a primary role in
-determining both spatial and temporal relationships. For example, in
-<a href="#ttml-example-body"><b>Example Fragment – TTML Body</b></a>, each paragraph (<code>p</code> element)
-is flowed into its target region in the specified lexical order; furthermore,
-the active time interval of each paragraph is timed in accordance to its
-parent or sibling according to the applicable time containment semantics —
-in this case, the division parent is interpreted (by default) as a parallel time
-container.</p><a id="ttml-example-body"></a><table class="example"><caption>Example Fragment – TTML Body</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;body region="subtitleArea"&gt;
-  &lt;div&gt;
-    &lt;p xml:id="subtitle1" begin="0.76s" end="3.45s"&gt;
-      It seems a paradox, does it not,
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle2" begin="5.0s" end="10.0s"&gt;
-      that the image formed on&lt;br/&gt;
-      the Retina should be inverted?
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle3" begin="10.0s" end="16.0s" style="s2"&gt;
-      It is puzzling, why is it&lt;br/&gt;
-      we do not see things upside-down?
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle4" begin="17.2s" end="23.0s"&gt;
-      You have never heard the Theory,&lt;br/&gt;
-      then, that the Brain also is inverted?
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle5" begin="23.0s" end="27.0s" style="s2"&gt;
-      No indeed! What a beautiful fact!
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle6a" begin="28.0s" end="34.6s" style="s2Left"&gt;
-      But how is it proved?
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle6b" begin="28.0s" end="34.6s" style="s1Right"&gt;
-      Thus: what we call
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle7" begin="34.6s" end="45.0s" style="s1Right"&gt;
-      the vertex of the Brain&lt;br/&gt;
-      is really its base
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle8" begin="45.0s" end="52.0s" style="s1Right"&gt;
-      and what we call its base&lt;br/&gt;
-      is really its vertex,
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle9a" begin="53.5s" end="58.7s"&gt;
-      it is simply a question of nomenclature.
-    &lt;/p&gt;
-    &lt;p xml:id="subtitle9b" begin="53.5s" end="58.7s" style="s2"&gt;
-      How truly delightful!
-    &lt;/p&gt;
-  &lt;/div&gt;    
-&lt;/body&gt;
-</pre></div>
-</td></tr></tbody></table><p>The first subtitle <a href="#ttml-example-subtitle-1"><b>Subtitle 1 – Time Interval [0.76, 3.45)</b></a> is
-presented during the time interval 0.76 to 3.45 seconds.
-This
-subtitle inherits its font family, font size,
-foreground color, and text alignment from the region into which it is
-presented. Since no region is explicitly specified on the paragraph,
-the nearest ancestor that specifies a region determines the
-targeted region. Note also that content is presented
-at the bottom (after edge) of the containing region due to the <code>tts:displayAlign="after"</code>
-being specified on the region definition.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The notation "[<em>X</em>,<em>Y</em>]" denotes a closed
-interval from <em>X</em> to <em>Y</em>, including
-<em>X</em> and <em>Y</em>;
-"[<em>X</em>,<em>Y</em>)" denotes a right half-open
-interval from <em>X</em> to <em>Y</em>, including
-<em>X</em> but not including <em>Y</em>;
-"(<em>X</em>,<em>Y</em>]" denotes a left half-open
-interval from <em>X</em> to <em>Y</em>, not including
-<em>X</em> but including <em>Y</em>;
-"(<em>X</em>,<em>Y</em>)" denotes an open
-interval from <em>X</em> to <em>Y</em>, not including
-<em>X</em> or <em>Y</em>.
-</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>In this example, the <code>p</code> element is used as a presentational
-element rather than as a semantic element, i.e., as a linguistic paragraph.
-It is up to an author to determine which TTML elements are used to convey
-the intended meaning. For instance, this example could be written to use
-timing on <code>span</code> elements in order to preserve the integrity of
-semantic paragraphs.</p></div><a id="ttml-example-subtitle-1"></a><table class="example-images"><caption>Subtitle 1 – Time Interval [0.76, 3.45)</caption><tbody><tr><td><img src="images/subtitle1.png" alt="Subtitle 1"></td></tr></tbody></table><p>The second subtitle continues with the default style, except that it contains
-two lines of text with an intervening author-specified line break. Note the effects of
-the use of <code>tts:textAlign="center"</code> to specify the paragraph's alignment
-in the inline progression direction.</p><a id="ttml-example-subtitle-2"></a><table class="example-images"><caption>Subtitle 2 – Time Interval [5.0, 10.0)</caption><tbody><tr><td><img src="images/subtitle2.png" alt="Subtitle 2"></td></tr></tbody></table><p>The third subtitle continues, using a variant style which overrides the default style's
-foreground color with a different color.</p><a id="ttml-example-subtitle-3"></a><table class="example-images"><caption>Subtitle 3 – Time Interval [10.0, 16.0)</caption><tbody><tr><td><img src="images/subtitle3.png" alt="Subtitle 3"></td></tr></tbody></table><p>The fourth subtitle reverts to the default style.</p><a id="ttml-example-subtitle-4"></a><table class="example-images"><caption>Subtitle 4 – Time Interval [17.2, 23.0)</caption><tbody><tr><td><img src="images/subtitle4.png" alt="Subtitle 4"></td></tr></tbody></table><p>The fifth subtitle continues, again using a variant style which
-overrides the default style's foreground color with a different color.</p><a id="ttml-example-subtitle-5"></a><table class="example-images"><caption>Subtitle 5 – Time Interval [23.0, 27.0)</caption><tbody><tr><td><img src="images/subtitle5.png" alt="Subtitle 5"></td></tr></tbody></table><p>During the next active time interval, two distinct subtitles are simultaneously active, with
-the paragraphs expressing each subtitle using different styles that override color and paragraph
-text alignment of the default style. Note that the flow order is determined by the lexical
-order of elements as they appear in the content hierarchy.</p><a id="ttml-example-subtitle-6"></a><table class="example-images"><caption>Subtitles 6a and 6b – Time Interval [28.0, 34.6)</caption><tbody><tr><td><img src="images/subtitle6.png" alt="Subtitles 6a and 6b"></td></tr></tbody></table><p>The next subtitle is specified in a similar manner using
-a style override to give the paragraph right (end) justification in the
-inline progression direction.</p><a id="ttml-example-subtitle-7"></a><table class="example-images"><caption>Subtitle 7 – Time Interval [34.6, 45.0)</caption><tbody><tr><td><img src="images/subtitle7.png" alt="Subtitles 7a and 7b"></td></tr></tbody></table><p>The eighth subtitle uses the same style override as the previous
-subtitle in order to maintain the right (end) justification of the
-paragraph.</p><a id="ttml-example-subtitle-8"></a><table class="example-images"><caption>Subtitle 8 – Time Interval [47.3, 49.0)</caption><tbody><tr><td><img src="images/subtitle8.png" alt="Subtitle 8"></td></tr></tbody></table><p>During the final (ninth) active time interval, two distinct
-subtitles are again simultaneously active, but with a different
-style applied to the second paragraph to override the default color.
-Note that the flow order is determined by the lexical order of
-elements as they appear in the content hierarchy.</p><a id="ttml-example-subtitle-9"></a><table class="example-images"><caption>Subtitles 9a and 9b – Time Interval [53.5, 58.7)</caption><tbody><tr><td><img src="images/subtitle9.png" alt="Subtitles 9a and 9b"></td></tr></tbody></table><p>The examples shown above demonstrate the primary types of information that may
-be authored using TTML: metadata, styling, layout, timing, and content. In typical cases,
-styling and layout information are separately specified in a <a href="#terms-document-instance">document instance</a>. Content information
-is expressed in a hierarchical fashion that embodies the organization of both spatial (flow) and
-timing information. Content makes direct or indirect references to styling and layout information
-and may specify inline overrides to styling.</p></div></div><div class="div1">
-<h2><a id="definitions"></a>2 Definitions</h2><div class="div2">
-<h3><a id="acronyms"></a>2.1 Acronyms</h3><table class="acronyms" summary="Glossary List"><tr><td class="label"><b>DFXP</b></td><td class="def"><p>Distribution Format Exchange Profile</p></td></tr><tr><td class="label"><b>ISD</b></td><td class="def"><p>Intermediate Synchronic Document</p></td></tr><tr><td class="label"><b>TT</b></td><td class="def"><p>Timed Text</p></td></tr><tr><td class="label"><b>TTML</b></td><td class="def"><p>Timed Text Markup Language</p></td></tr><tr><td class="label"><b>TTAF</b></td><td class="def"><p>Timed Text Authoring Format</p></td></tr><tr><td class="label"><b>TTWG</b></td><td class="def"><p>Timed Text Working Group</p></td></tr></table></div><div class="div2">
-<h3><a id="terms"></a>2.2 Terminology</h3><dl><dt class="label"><a id="terms-abstract-document-instance"></a>[abstract document instance]</dt><dd><p>An instance of an abstract data set as represented by a
-<a href="#terms-reduced-xml-infoset">reduced xml infoset</a>.</p></dd><dt class="label"><a id="terms-abstract-document-type"></a>[abstract document type]</dt><dd><p>A set of constraints that defines a class of <em>XML Information
-Sets</em> <a href="#infoset">[XML InfoSet]</a>.</p></dd><dt class="label"><a id="terms-anonymous-profile"></a>[anonymous profile]</dt><dd><p>See <a href="#terms-undesignated-profile">undesignated profile</a>.</p></dd><dt class="label"><a id="terms-attribute-information-item"></a>[attribute information item]</dt><dd><p>Each specified or defaulted attribute  of an XML document corresponds with an attribute information
-item as defined by <a href="#infoset">[XML InfoSet]</a>, §2.3.</p></dd><dt class="label"><a id="terms-audio-defining-context"></a>[audio defining context]</dt><dd><p>The context in which an <a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element is specified to serve as
-a sharable definition to be referenced by another <a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element
-in an <a href="#terms-audio-presentation-context">audio presentation context</a>.</p></dd><dt class="label"><a id="terms-audio-presentation-context"></a>[audio presentation context]</dt><dd><p>The context in which an <a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element is specified for the
-purpose of being presented (rendered). Such an <a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element
-may specify the audio data inline by using a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element within
-a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element child, or it may reference another
-<a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element specified in a 
-<a href="#terms-audio-definition-context">audio definition context</a>, or it may do both.</p></dd><dt class="label"><a id="terms-audio-resource"></a>[audio resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> that contains coded or unencoded audio samples.</p></dd><dt class="label"><a id="terms-authoring-viewport"></a>[authoring viewport]</dt><dd><p>A <a href="#terms-viewport">viewport</a> employed at authoring (content encoding) time.</p></dd><dt class="label"><a id="terms-baseline-profile"></a>[baseline profile]</dt><dd><p>A <a href="#terms-profile">profile</a> referenced by the <code>use</code> attribute of a <code>ttp:profile</code> element,
-which serves as a baseline (initial) set of specifications with which to populate the referencing profile.</p></dd><dt class="label"><a id="terms-block-display"></a>[block display]</dt><dd><p>Block display is a set of layout semantics that may be applied to a <a href="#terms-content-element">content element</a> in
-certain contexts, wherein child areas are composed sequentially in the block progression direction. In <a href="#css2">[CSS2]</a>,
-block display is indicated when a CSS <code>display</code> property with the value <code>block</code> is applied to a
-<a href="#terms-content-element">content element</a> during presentation processing. In <a href="#xsl11">[XSL 1.1]</a>, a block display
-occurs when composing a <code>fo:block</code> element.</p></dd><dt class="label"><a id="terms-character-information-item"></a>[character information item]</dt><dd><p>Each data character appearing in an XML document corresponds with a character information
-item as defined by <a href="#infoset">[XML InfoSet]</a>, §2.6.</p></dd><dt class="label"><a id="terms-chunked-data-embedding"></a>[chunked data embedding]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element that directly embeds a representation of the actual bytes
-of an <a href="#terms-embedded-data-resource">embedded data resource</a> by making use of a
-child <a href="#embedded-content-vocabulary-chunk"><code>chunk</code></a> element.</p></dd><dt class="label"><a id="terms-computed-cell-size"></a>[computed cell size]</dt><dd><p>The size (extent) of a cell computed by dividing the width of the <a href="#terms-root-container-region">root container region</a>
-by the column count, i.e., the number of cells in the horizontal axis, and by dividing
-the height of the <a href="#terms-root-container-region">root container region</a> by the row count, i.e., the number of cells in the vertical
-axis, where the column and row counts are determined by the <code>ttp:cellResolution</code> parameter attribute.</p></dd><dt class="label"><a id="terms-content-element"></a>[content element]</dt><dd><p>Any of the element types defined by the <a href="#element-vocab-type-content">Content Module</a>.</p></dd><dt class="label"><a id="terms-content-image"></a>[content image]</dt><dd><p>An <a href="#terms-image-resource">image resource</a> that contains semantically significant content, e.g., a raster image
-representing the rendering of a caption.</p></dd><dt class="label"><a id="terms-content-processor"></a>[content processor]</dt><dd><p>A processing system capable of importing (receiving) Timed Text Markup Language
-content for the purpose of transforming, presenting, or otherwise processing the content.</p></dd><dt class="label"><a id="terms-content-profile"></a>[content profile]</dt><dd><p>A collection of <a href="#terms-feature">features</a> and <a href="#terms-extension">extensions</a> that must not, must, or may be employed by
-Timed Text Markup Language content.</p><p></p></dd><dt class="label"><a id="terms-content-region"></a>[content region]</dt><dd><p>A logical region into which rendered content is placed when modeling or
-performing presentation processing.</p><table border="1" class="ednote" summary="Editorial note: Content Region vs Region"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Content Region vs Region</b></td><td align="right" valign="top">2014-12-10</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Clean up terminology regarding content region vs region, which difference is vague at best.</td></tr></table><p></p></dd><dt class="label"><a id="terms-data-binding-context"></a>[data binding context]</dt><dd><p>The context in which an <a href="#embedded-content-vocabulary-data"><code>data</code></a> element is specified for the
-purpose of semantic binding (association). Such a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element
-may specify the data inline by using a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element within
-a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element child, or it may reference another
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element specified in a 
-<a href="#terms-data-definition-context">data definition context</a>, or it may do both. No presentation (rendering)
-semantics are implied by the mere presence of a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element in this (or any) context.</p></dd><dt class="label"><a id="terms-data-binding-context-for-metadata"></a>[data binding context for metadata]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element the parent of which is a
-<a href="#metadata-vocabulary-metadata"><code>metadata</code></a> element.</p></dd><dt class="label"><a id="terms-data-binding-context-for-source"></a>[data binding context for source]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element the parent of which is a
-<a href="#embedded-content-vocabulary-source"><code>source</code></a> element.</p></dd><dt class="label"><a id="terms-data-defining-context"></a>[data defining context]</dt><dd><p>The context in which an <a href="#embedded-content-vocabulary-data"><code>data</code></a> element is specified to serve as
-a sharable definition to be referenced by another <a href="#embedded-content-vocabulary-data"><code>data</code></a> element
-in an <a href="#terms-data-binding-context">data binding context</a>, namely, a
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element the parent of which is a
-<a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element.</p></dd><dt class="label"><a id="terms-data-element"></a>[data element]</dt><dd><p>Any of the element types defined by the <a href="#element-vocab-type-data">Data Module</a>.</p></dd><dt class="label"><a id="terms-data-resource"></a>[data resource]</dt><dd><p>An arbitrary data resource represented or referenced using a <a href="#terms-data-element">data element</a>. For example,
-a data resource may be used to embed or refer to an audio clip, a font, an image, or arbitrary application data in a
-<a href="#terms-timed-text-content-document-instance">timed text content document instance</a>.</p></dd><dt class="label"><a id="terms-default-profile"></a>[default processor profile]</dt><dd><p>A default <a href="#terms-processor-profile">processor profile</a> used to compute an
-<a href="#terms-effective-processor-profile">effective processor profile</a> in the absence of a declared or inferred
-<a href="#terms-processor-profile">processor profile</a>, where this default processor profile is determined by
-the <a href="#semantics-procedure-construct-default-processor-profile"><span class="strong">construct default processor profile</span></a>
-procedure.</p></dd><dt class="label"><a id="terms-default-region"></a>[default region]</dt><dd><p>A default <a href="#terms-out-of-line-region">out-of-line region</a> that is implied in the absence of
-an explicitly specified out-of-line <a href="#layout-vocabulary-region"><code>region</code></a> element, i.e.,
-when no <a href="#layout-vocabulary-region"><code>region</code></a> element is specified as a child of
-a <a href="#layout-vocabulary-layout"><code>layout</code></a> element.</p></dd><dt class="label"><a id="terms-designated-profile"></a>[designated profile]</dt><dd><p>A <a href="#terms-profile">profile</a> that is associated with a <a href="#terms-profile-designator">profile designator</a> by
-means of a <code>designator</code> attribute or prose text in a specification of profile.</p></dd><dt class="label"><a id="terms-display-aspect-ratio"></a>[display aspect ratio]</dt><dd><p>The ratio between the horizontal dimension and vertical dimension of a displayed image, video frame,
-viewport or region, display device, etc. Equal to the product of <a href="#terms-storage-aspect-ratio">storage aspect ratio</a>
-and <a href="#terms-pixel-aspect-ratio">pixel aspect ratio</a>.</p></dd><dt class="label"><a id="terms-display-region-target"></a>[display region target]</dt><dd><p>A <a href="#terms-viewport">viewport</a> targeted to a rectangular region of a display device, i.e., not in full-screen mode.</p></dd><dt class="label"><a id="terms-display-target"></a>[display target]</dt><dd><p>A <a href="#terms-viewport">viewport</a> targeted to a display device as a whole, i.e., in full-screen mode.</p></dd><dt class="label"><a id="terms-document-coordinate-space"></a>[document coordinate space]</dt><dd><p></p><table border="1" class="ednote" summary="Editorial note: Document Coordinate Space Definition"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Document Coordinate Space Definition</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Either define or express in terms of (some) viewport.</td></tr></table><p></p></dd><dt class="label"><a id="terms-document-instance"></a>[document instance]</dt><dd><p>A <a href="#terms-timed-text-document-instance">timed text document instance</a>.</p></dd><dt class="label"><a id="terms-document-interchange-context"></a>[document interchange context]</dt><dd><p>The implied context or environment external to a <a href="#terms-content-processor">content processor</a> in
-which document interchange occurs, and in which out-of-band protocols or specifications
-may define certain behavioral defaults, such as an implied profile.</p></dd><dt class="label"><a id="terms-document-processing-context"></a>[document processing context]</dt><dd><p>The implied context or environment internal to a <a href="#terms-content-processor">content processor</a> in
-which document processing occurs, and in which out-of-band protocols or specifications
-may define certain behavioral defaults, such as the establishment or creation of a
-<a href="#terms-synthetic-document-syncbase">synthetic document syncbase</a>.</p></dd><dt class="label"><a id="terms-dot-pitch"></a>[dot pitch]</dt><dd><p>Depending upon display device technology, the distance between holes in the shadow mask, the distance between wires in the aperture grill,
-the distance between sub-pixels of the same color, etc.</p></dd><dt class="label"><a id="terms-effective-content-profile"></a>[effective content profile]</dt><dd><p>The <a href="#terms-content-profile">content profile</a> computed from the set of all <a href="#terms-content-profile">content profiles</a>
-explicitly or implicitly referenced by or assigned to a TTML <a href="#terms-document-instance">document instance</a> after applying any
-explicit or implicit profile and profile specification combination methods. When performing validation on a given <a href="#terms-document-instance">document instance</a>,
-then this validation is performed by making use of a document's <a href="#terms-effective-content-profile">effective content profile</a>.</p></dd><dt class="label"><a id="terms-effective-processor-profile"></a>[effective processor profile]</dt><dd><p>The <a href="#terms-processor-profile">processor profile</a> computed from the set of all <a href="#terms-processor-profile">processor profiles</a>
-explicitly or implicitly referenced by or assigned to a TTML <a href="#terms-document-instance">document instance</a> after applying any
-explicit or implicit profile and profile specification combination methods. When determining if a <a href="#terms-content-processor">content processor</a>
-can or cannot process a given <a href="#terms-document-instance">document instance</a>, then this determination is performed
-by making use of a document's <a href="#terms-effective-processor-profile">effective processor profile</a>.</p></dd><dt class="label"><a id="terms-element-information-item"></a>[element information item]</dt><dd><p>Each element appearing in an XML document corresponds with an element information
-item as defined by <a href="#infoset">[XML InfoSet]</a>, §2.2.</p></dd><dt class="label"><a id="terms-embedded-content-element"></a>[embedded content element]</dt><dd><p>Any of the element types defined by the <a href="#element-vocab-type-audio">Audio Module</a>,
-<a href="#element-vocab-type-data">Data Module</a>,
-<a href="#element-vocab-type-font">Font Module</a>, or
-<a href="#element-vocab-type-image">Image Module</a>.</p></dd><dt class="label"><a id="terms-embedded-data-resource"></a>[embedded data resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> embedded in a
-<a href="#terms-timed-text-content-document-instance">timed text content document instance</a>, represented by means of
-a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element, whether or not that
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element represents the actual bytes of the <a href="#terms-data-resource">data resource</a>
-or refers to an <a href="#terms-external-data-resource">external data resource</a>
-</p></dd><dt class="label"><a id="terms-enclosing-document-instance"></a>[enclosing document instance]</dt><dd><p>The <a href="#terms-document-instance">document instance</a> that encloses or otherwise contains
-an enclosed feature or component.</p></dd><dt class="label"><a id="terms-exchange-profile"></a>[exchange profile]</dt><dd><p>A profile of content that serves a set of needs for content interchange.</p></dd><dt class="label"><a id="terms-extension"></a>[extension]</dt><dd><p>A syntactic or semantic expression or capability that is defined and
-labeled (using a extension designation) in another (public or private)
-specification.</p></dd><dt class="label"><a id="terms-extension-specification"></a>[extension specification]</dt><dd><p>A specification of a constraint or requirement that relates to an
-<a href="#terms-extension">extension</a>, typically expressed by
-an <a href="#profile-vocabulary-extension"><code>ttp:extension</code></a> element.</p></dd><dt class="label"><a id="terms-external-data-resource"></a>[external data resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> external to a
-<a href="#terms-timed-text-content-document-instance">timed text content document instance</a>, referenced by means
-of a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element or a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute
-of a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element or <a href="#terms-embedded-content-element">embedded content element</a>.</p></dd><dt class="label"><a id="terms-external-source"></a>[external source]</dt><dd><p>Either (1) a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element or a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute
-that refers to an <a href="#terms-external-data-resource">external data resource</a> or (2) the referenced
-<a href="#terms-external-data-resource">external data resource</a>.</p></dd><dt class="label"><a id="terms-feature"></a>[feature]</dt><dd><p>A syntactic or semantic expression or capability that is defined and
-labeled (using a feature designation) in this specification (or a past or
-future revision of this specification).</p></dd><dt class="label"><a id="terms-feature-specification"></a>[feature specification]</dt><dd><p>A specification of a constraint or requirement that relates to an
-<a href="#terms-feature">feature</a>, typically expressed by
-an <a href="#profile-vocabulary-feature"><code>ttp:feature</code></a> element.</p></dd><dt class="label"><a id="terms-forced-subtitle"></a>[forced subtitle]</dt><dd><p>A subtitle (or caption) that is intended to always be displayed even if subtitles (captions) are not enabled. Forced subtitles (captions)
-are used to prevent open captioning of, i.e., burning in, subtitles (captions) related to foreign or alien language or translation of text
-that appears in media, such as in a sign.</p></dd><dt class="label"><a id="terms-font-defining-context"></a>[font defining context]</dt><dd><p>The context in which a <a href="#embedded-content-vocabulary-font"><code>font</code></a> element is specified to serve as
-a sharable definition to be referenced indirectly by a <a href="#terms-font-selection-process">font selection process</a>.</p></dd><dt class="label"><a id="terms-font-selection-process"></a>[font selection process]</dt><dd><p>An internal process used by a <a href="#terms-presentation-processor">presentation processor</a> which purpose is to select
-a set of author defined fonts and platform fonts for use during layout and presentation processing, where input parameters to this
-process include the computed values of font related properties, the capabilities of individual fonts, and the text content being presented.</p></dd><dt class="label"><a id="terms-font-resource"></a>[font resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> that contains font information, such as character to glyph mapping data, glyph outlines or images,
-glyph metrics, and other data used in the character to glyph mapping and rendering process.</p></dd><dt class="label"><a id="terms-fragment-identifier"></a>[fragment identifier]</dt><dd><p>A syntactic expression that adheres to the fragment identifer syntax defined by <a href="#uri">[URI]</a>,
-Section 4.1.</p></dd><dt class="label"><a id="terms-image-defining-context"></a>[image defining context]</dt><dd><p>The context in which an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element is specified to serve as
-a sharable definition to be referenced by another <a href="#embedded-content-vocabulary-image"><code>image</code></a> element
-in an <a href="#terms-image-presentation-context">image presentation context</a>.</p></dd><dt class="label"><a id="terms-image-presentation-context"></a>[image presentation context]</dt><dd><p>The context in which an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element is specified for the
-purpose of being presented (rendered). Such an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element
-may specify the image data inline by using a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element within
-a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element child, or it may reference another
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element specified in a 
-<a href="#terms-image-definition-context">image definition context</a>, or it may do both.</p></dd><dt class="label"><a id="terms-image-resource"></a>[image resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> that contains a raster image.</p></dd><dt class="label"><a id="terms-implied-inline-region"></a>[implied inline region]</dt><dd><p>An anonymous (unidentified) <a href="#terms-inline-region">inline region</a> that is implied in the context of a block level
-<a href="#terms-content-element">content element</a>
-due the presence of a <a href="#style-attribute-extent"><code>tts:extent</code></a> or <a href="#style-attribute-origin"><code>tts:origin</code></a>
-style attribute on the <a href="#terms-content-element">content element</a>.</p></dd><dt class="label"><a id="terms-inline-animation"></a>[inline animation]</dt><dd><p>An <a href="#animation-vocabulary-animate"><code>animate</code></a> or <a href="#animation-vocabulary-set"><code>set</code></a> element
-that is defined inline as an immediate child of
-a <a href="#terms-content-element">content element</a> or <a href="#layout-vocabulary-region"><code>region</code></a> element associated with the animation.
-There is a one-to-one relation between
-an inline animation element and its parent <a href="#terms-content-element">content element</a> or <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></dd><dt class="label"><a id="terms-inline-block-display"></a>[inline block display]</dt><dd><p>Inline block display is a set of layout semantics that may be applied to a <a href="#terms-content-element">content element</a> in
-certain contexts, wherein a generated block area is treated as an an atomic area to be composed in an inline layout context, i.e., the block
-area is treated as if it were itself an inline area when considered externally, but as a block area which considered internally. In <a href="#css2">[CSS2]</a>,
-inline block display is indicated when a CSS <code>display</code> property with the value <code>inline-block</code> is applied to a
-<a href="#terms-content-element">content element</a> during presentation processing. In <a href="#xsl11">[XSL 1.1]</a>, an inline block display
-occurs when block content appears in an inline content context, e.g., when a <code>fo:block</code> appears as a child of <code>fo:inline</code>.</p></dd><dt class="label"><a id="terms-inline-display"></a>[inline display]</dt><dd><p>Inline display is a set of layout semantics that may be applied to a <a href="#terms-content-element">content element</a> in
-certain contexts, wherein child areas are composed sequentially in the inline progression direction. In <a href="#css2">[CSS2]</a>,
-inline display is indicated when a CSS <code>display</code> property with the value <code>inline</code> is applied to a
-<a href="#terms-content-element">content element</a> during presentation processing. In <a href="#xsl11">[XSL 1.1]</a>, an inline display
-occurs when composing a <code>fo:inline</code> element.</p></dd><dt class="label"><a id="terms-inline-region"></a>[inline region]</dt><dd><p>A <a href="#terms-region">region</a> that is defined in an inline manner with respect to some
-<a href="#terms-content-element">content element</a>  to be selected into (targeted to) the region.
-An inline region is specified either explicitly by a <a href="#layout-vocabulary-region"><code>region</code></a> element child of
-a <a href="#terms-content-element">content element</a> or implicitly by specifying a <a href="#style-attribute-extent">tts:extent</a>
-or <a href="#style-attribute-origin">tts:origin</a> style attribute on a <a href="#terms-content-element">content element</a>.
-There is a one-to-one relation between an inline <a href="#layout-vocabulary-region"><code>region</code></a> element and its
-parent <a href="#terms-content-element">content element</a>. An inline region is assigned its parent element's time interval as its active
-time interval. No <code>region</code> attribute makes reference to an inline region.</p></dd><dt class="label"><a id="terms-intermediate-synchronic-document"></a>[intermediate synchronic document]</dt><dd><p>A <a href="#terms-timed-text-intermediate-document">timed text intermediate document</a> or a
-<a href="#terms-timed-text-intermediate-document-instance">timed text intermediate document instance</a>, according to the context of use,
-where the root (document) element is an <code>isd:isd</code> element, and which represents a
-non-overlapping temporal interval that intersects with the content, styling, layout, and timing of a source
-<a href="#terms-timed-text-content-document">timed text content document</a>.</p></dd><dt class="label"><a id="terms-intermediate-synchronic-document-sequence"></a>[intermediate synchronic document sequence]</dt><dd><p>A <a href="#terms-timed-text-intermediate-document">timed text intermediate document</a> or a
-<a href="#terms-timed-text-intermediate-document-instance">timed text intermediate document instance</a>, according to the context of use,
-where the root (document) element is an <code>isd:sequence</code> element, and which represents a
-sequence of <a href="#terms-intermediate-synchronic-document">intermediate synchronic document</a> instances
-that effectively represent the content, styling, layout, and timing of a source <a href="#terms-timed-text-content-document">timed text content document</a>.</p></dd><dt class="label"><a id="terms-intermediate-document-syntax"></a>[intermediate document syntax]</dt><dd><p>A formalism for use in the concrete representation of an <a href="#terms-intermediate-synchronic-document-sequence">intermediate synchronic document sequence</a> or
-an <a href="#terms-intermediate-synchronic-document">intermediate synchronic document</a>.</p></dd><dt class="label"><a id="terms-nested-profile"></a>[nested profile]</dt><dd><p>A constituent <a href="#terms-profile">profile</a> of a <a href="#terms-nesting-profile">nesting profile</a>, i.e., one of the
-descendant <code>ttp:profile</code> element(s) of a higher level (ancestor) <code>ttp:profile</code> element. A given <code>ttp:profile</code> may serve
-as both a <a href="#terms-nested-profile">nested profile</a> and a <a href="#terms-nesting-profile">nesting profile</a>.</p></dd><dt class="label"><a id="terms-nesting-profile"></a>[nesting profile]</dt><dd><p>A <a href="#terms-profile">profile</a> defined by making reference to one or more child <code>ttp:profile</code> element(s), wherein a
-profile combination method determines how profile specifications from the multiple child <code>ttp:profile</code> element(s) are combined.</p></dd><dt class="label"><a id="terms-nested-embedded-source"></a>[nested embedded source]</dt><dd><p>A <a href="#embedded-content-vocabulary-source"><code>source</code></a> element that specifies a child 
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element which embeds the actual bytes of the
-<a href="#terms-embedded-data-resource">embedded data resource</a>, whether by 
-<a href="#terms-simple-data-embedding">simple data embedding</a> or <a href="#terms-chunked-data-embedding">chunked data embedding</a>.</p></dd><dt class="label"><a id="terms-non-content-image"></a>[non-content image]</dt><dd><p>An <a href="#terms-image-resource">image resource</a> that does not contain semantically significant content, e.g., a raster image
-representing a background design, which, if not presented, would not affect the presentation of semntically significant content.</p></dd><dt class="label"><a id="terms-non-nested-embedded-source"></a>[non-nested embedded source]</dt><dd><p>A <a href="#embedded-content-vocabulary-source"><code>source</code></a> element that specifies a child 
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element which does not embed a representation of the actual bytes of the
-<a href="#terms-embedded-data-resource">embedded data resource</a>.</p></dd><dt class="label"><a id="terms-non-nesting-profile"></a>[non-nesting profile]</dt><dd><p>A <a href="#terms-profile">profile</a> defined without making reference to one or more child <code>ttp:profile</code> element(s); that is,
-by including only child <code>ttp:features</code> and <code>ttp:extensions</code> element(s).</p></dd><dt class="label"><a id="terms-out-of-line-animation"></a>[out-of-line animation]</dt><dd><p>An <a href="#animation-vocabulary-animate"><code>animate</code></a> or <a href="#animation-vocabulary-set"><code>set</code></a> element that is defined out-of-line from
-the <a href="#terms-content-element">content element</a> or <a href="#layout-vocabulary-region"><code>region</code></a> element associated with the animation.
-An out-of-line animation appears as a child of an <a href="#animation-vocabulary-animation"><code>animation</code></a> element in the header
-(<a href="#document-structure-vocabulary-head"><code>head</code></a> element)
-of a <a href="#terms-document-instance">document instance</a>, and specifies an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute
-which value is referenced by an <a href="#animation-attribute-animate"><code>animate</code></a> attribute
-on the associated element to be animated. There is a one-to-many relation between
-a referenced out-of-line animation element and referencing <a href="#terms-content-element">content elements</a> and
-<a href="#layout-vocabulary-region"><code>region</code></a> elements.</p></dd><dt class="label"><a id="terms-out-of-line-region"></a>[out-of-line region]</dt><dd><p>A <a href="#layout-vocabulary-region"><code>region</code></a> element that is defined out-of-line from
-a <a href="#terms-content-element">content element</a> associated with (to be selected into) the region.
-An out-of-line region appears as a child of a <a href="#layout-vocabulary-layout"><code>layout</code></a> element in the header
-(<a href="#document-structure-vocabulary-head"><code>head</code></a> element)
-of a <a href="#terms-document-instance">document instance</a>, and specifies an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute
-which value is referenced by a <a href="#layout-attribute-region"><code>region</code></a> attribute
-on the associated element to be selected into the region. There is a one-to-many relation between
-a referenced out-of-line region element and referencing <a href="#terms-content-element">content elements</a>.
-A <a href="#terms-default-region">default out-of-line region</a> is implied if no
-<a href="#terms-out-of-line-region">out-of-line region</a> is specified explicitly.</p></dd><dt class="label"><a id="terms-pixel-aspect-ratio"></a>[pixel aspect ratio]</dt><dd><p>The ratio between the horizontal dimension and vertical dimension of a displayed pixel. Note that the dimensions of a display pixel may or may not
-correspond to the <a href="#terms-dot-pitch">dot pitch</a> of the display device on which it is rendered.</p></dd><dt class="label"><a id="terms-presentation-context-coordinate-space"></a>[presentation context coordinate space]</dt><dd><p></p><table border="1" class="ednote" summary="Editorial note: Presentation Context Coordinate Space Definition"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Presentation Context Coordinate Space Definition</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Either define or express in terms of (some) viewport.</td></tr></table><p></p></dd><dt class="label"><a id="terms-presentation-processor"></a>[presentation processor]</dt><dd><p>A <a href="#terms-content-processor">content processor</a> which purpose is to layout, format, and render,
-i.e., to present, <a href="#terms-timed-text-markup-language">Timed Text Markup Language</a> content by applying the presentation semantics
-defined in this specification.</p></dd><dt class="label"><a id="terms-presentation-viewport"></a>[presentation viewport]</dt><dd><p>A <a href="#terms-viewport">viewport</a> employed at presentation (content decoding) time.</p><p>Note well that the characteristics of a <a href="#presentation-viewport">presentation viewport</a> may or may not
-match the characteristics of the <a href="#authoring-viewport">authoring viewport</a> used when content was authored (encoded).
-In particular, the <a href="#terms-storage-aspect-ratio">storage aspect ratio</a> and (or) the <a href="#terms-pixel-aspect-ratio">pixel aspect ratio</a>
-of the former may differ from that of the latter.</p></dd><dt class="label"><a id="terms-processor"></a>[processor]</dt><dd><p>See <a href="#terms-content-processor">content processor</a>.</p></dd><dt class="label"><a id="terms-processor-profile"></a>[processor profile]</dt><dd><p>A collection of <a href="#terms-feature">features</a> and <a href="#terms-extension">extensions</a> that must or may be implemented (supported) by
-a content processor.</p></dd><dt class="label"><a id="terms-profile"></a>[profile]</dt><dd><p>A <a href="#terms-content-profile">content profile</a> or <a href="#terms-processor-profile">processor profile</a>.</p></dd><dt class="label"><a id="terms-profile-definition-document"></a>[profile definition document]</dt><dd><p>A <a href="#terms-timed-text-profile-document">timed text profile document</a> or a
-<a href="#terms-timed-text-profile-document-instance">timed text profile document instance</a>, according to the context of use.</p></dd><dt class="label"><a id="terms-profile-designator"></a>[profile designator]</dt><dd><p>An absolute URI used to label or reference an externally defined <a href="#terms-profile">profile</a>, where
-external refers to being external to a <a href="#terms-document-instance">document instance</a>.</p></dd><dt class="label"><a id="terms-profile-fragment-identifier"></a>[profile fragment identifier]</dt><dd><p>A <a href="#terms-fragment-identifier">fragment identifier</a> used to label or reference an internally defined <a href="#terms-profile">profile</a>, where
-internal refers to being internal to a <a href="#terms-document-instance">document instance</a>.</p></dd><dt class="label"><a id="terms-profile-specification"></a>[profile specification]</dt><dd><p>A <a href="#terms-feature-specification">feature specification</a> or an <a href="#terms-extension-specification">extension specification</a>
-or the internal state representation thereof.</p></dd><dt class="label"><a id="terms-region"></a>[region]</dt><dd><p>A logical construct that models authorial intention regarding
-desired or potential presentation processing, and which is represented as
-a rectangular area of a presentation surface into which content
-is composed and rendered during presentation processing.</p></dd><dt class="label"><a id="terms-reduced-xml-infoset"></a>[reduced xml infoset]</dt><dd><p>An XML Information Set <a href="#infoset">[XML InfoSet]</a> that satisfies the
-constraints specify by <a href="#reduced-infoset"><b>B Reduced XML Infoset</b></a>.</p></dd><dt class="label"><a id="terms-related-media-object"></a>[related media object]</dt><dd><p>A (possibly null) media object associated with or otherwise related
-to a <a href="#terms-document-instance">document instance</a>. For example, an aggregate audio/video media
-object for which a <a href="#terms-document-instance">document instance</a> provides caption or subtitle
-information, and with which that <a href="#terms-document-instance">document instance</a> is associated.</p></dd><dt class="label"><a id="terms-related-media-object-region"></a>[related media object region]</dt><dd><p>When a non-null <a href="#terms-related-media-object">related media object</a> exists, the region of this media object,
-expressed in the coordinate system that applies to the <a href="#terms-document-instance">document instance</a> that is associated with the
-related media object.</p><table border="1" class="ednote" summary="Editorial note: Update Definition of Related Media Object Region"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Update Definition of Related Media Object Region</b></td><td align="right" valign="top">2014-12-02</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Untangle definition from use of document coordinate space.</td></tr></table><p></p></dd><dt class="label"><a id="terms-related-media-object-region-target"></a>[related media object region target]</dt><dd><p>A <a href="#terms-viewport">viewport</a> targeted to a <a href="#terms-related-media-object-region">related media object region</a>.</p></dd><dt class="label"><a id="terms-root-container-region"></a>[root container region]</dt><dd><p>A logical region that establishes a coordinate system into which
-<a href="#terms-content-region">content regions</a> are placed and optionally clipped.</p></dd><dt class="label"><a id="terms-root-temporal-extent"></a>[root temporal extent]</dt><dd><p>The temporal extent (interval) defined by the temporal beginning and ending of a <a href="#terms-document-instance">document instance</a>
-in relationship with some external application or presentation context.</p></dd><dt class="label"><a id="terms-simple-data-embedding"></a>[simple data embedding]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element the directly embeds a representation of the actual bytes
-of an <a href="#terms-embedded-data-resource">embedded data resource</a> without making use of a
-child <a href="#embedded-content-vocabulary-chunk"><code>chunk</code></a> element.</p></dd><dt class="label"><a id="terms-smpte-time-code"></a>[smpte time code]</dt><dd><p>A time code whose format and semantics are established by <a href="#smpte12m">[SMPTE 12M]</a>,
-which may be embedded into or otherwise associated with media content, such
-as a broadcast audio/video stream.</p></dd><dt class="label"><a id="terms-sourced-data-embedding"></a>[sourced data embedding]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element that indirectly references the content
-of an <a href="#terms-embedded-data-resource">embedded data resource</a> by making use of a
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element.</p></dd><dt class="label"><a id="terms-storage-aspect-ratio"></a>[storage aspect ratio]</dt><dd><p>The ratio between the number of horizontal samples and the number of vertical samples of a two-dimensional
-representation of an image, a video frame, a viewport or region, etc.</p></dd><dt class="label"><a id="terms-synthetic-document-syncbase"></a>[synthetic document syncbase]</dt><dd><p>A document level <a href="http://www.w3.org/TR/2008/REC-SMIL3-20081201/smil30.html#smil-timing-q158">syncbase</a>
-<a href="#smil3">[SMIL 3.0]</a>, § 5.7.1, synthesized or otherwise established by
-the <a href="#terms-document-processing-context">document processing context</a> in accordance with the
-<a href="#terms-related-media-object">related media object</a> or other processing criteria.</p></dd><dt class="label"><a id="terms-synthetic-smpte-document-syncbase"></a>[synthetic smpte document syncbase]</dt><dd><p>A <a href="#terms-synthetic-document-syncbase">synthetic document syncbase</a> constructed from <a href="#terms-smpte-time-code">smpte time code</a>
-values embedded in or associated with the <a href="#terms-related-media-object">related media object</a> or
-otherwise determined by the <a href="#terms-document-processing-context">document processing context</a>.</p></dd><dt class="label"><a id="terms-temporally-active"></a>[temporally active]</dt><dd><p>A syntactic or semantic feature, e.g., an element or the presentation of an element, is
-<em>temporally active</em> when the current time of selected time base intersects with the
-active time interval of the feature.</p></dd><dt class="label"><a id="terms-temporally-active-region"></a>[temporally active region]</dt><dd><p>A <a href="#terms-region">region</a> that is <a href="#terms-temporally-active">temporally active</a>.</p></dd><dt class="label"><a id="terms-timed-text"></a>[timed text]</dt><dd><p>Textual information that is intrinsically or extrinsically
-associated with timing information.</p></dd><dt class="label"><a id="terms-timed-text-authoring-system"></a>[timed text authoring system]</dt><dd><p>A content authoring system capable of importing and exporting
-Timed Text Markup Language content.</p></dd><dt class="label"><a id="terms-timed-text-content-document"></a>[timed text content document]</dt><dd><p>An abstract document that is purported or confirmed to be a
-<a href="#terms-valid-abstract-document-instance">valid abstract document instance</a> of
-the <a href="#ttml-content-doctype">TTML Content Document Type</a>.</p></dd><dt class="label"><a id="terms-timed-text-content-document-instance"></a>[timed text content document instance]</dt><dd><p>A concrete realization of a <a href="#terms-timed-text-content-document">timed text content document</a>,
-about which see <a href="#concrete-encoding"><b>A Concrete Encoding</b></a>.</p></dd><dt class="label"><a id="terms-timed-text-document-instance"></a>[timed text document instance]</dt><dd><p>A concrete realization of a
-<a href="#terms-timed-text-markup-language-document">timed text markup language document</a>,
-where  the concrete form is specific to the context of reference.
-Also referred to as a <a href="#terms-document-instance">TTML document instance</a>
-or simply <a href="#terms-document-instance">document instance</a>.</p></dd><dt class="label"><a id="terms-timed-text-intermediate-document"></a>[timed text intermediate document]</dt><dd><p>An abstract document that is purported or confirmed to be a
-<a href="#terms-valid-abstract-document-instance">valid abstract document instance</a> of
-the <a href="#ttml-intermediate-doctype">TTML Intermediate Document Type</a>.</p></dd><dt class="label"><a id="terms-timed-text-intermediate-document-instance"></a>[timed text intermediate document instance]</dt><dd><p>A concrete realization of a <a href="#terms-timed-text-intermediate-document">timed text intermediate document</a>,
-about which see <a href="#concrete-encoding"><b>A Concrete Encoding</b></a>.</p></dd><dt class="label"><a id="terms-timed-text-markup-language"></a>[timed text markup language]</dt><dd><p>A content type that represents timed text content, intermediate representations of this content, or profiles of this content or content processors.</p></dd><dt class="label"><a id="terms-timed-text-markup-language-document"></a>[timed text markup language document]</dt><dd><p>An abstract document that is purported or confirmed to be a
-<a href="#terms-valid-abstract-document-instance">valid abstract document instance</a>.</p></dd><dt class="label"><a id="terms-timed-text-profile-document"></a>[timed text profile document]</dt><dd><p>An abstract document that is purported or confirmed to be a
-<a href="#terms-valid-abstract-document-instance">valid abstract document instance</a> of
-the <a href="#ttml-profile-doctype">TTML Profile Document Type</a>.</p></dd><dt class="label"><a id="terms-timed-text-profile-document-instance"></a>[timed text profile document instance]</dt><dd><p>A concrete realization of a <a href="#terms-timed-text-profile-document">timed text profile document</a>,
-about which see <a href="#concrete-encoding"><b>A Concrete Encoding</b></a>.</p></dd><dt class="label"><a id="terms-top-level-profile"></a>[top-level profile]</dt><dd><p>A <a href="#terms-profile">profile</a> defined by a <code>ttp:profile</code> element that appears as a child
-of the <code>head</code> element.</p></dd><dt class="label"><a id="terms-transformation-processor"></a>[transformation processor]</dt><dd><p>A <a href="#terms-content-processor">content processor</a> which purpose is to transform or otherwise rewrite
-<a href="#terms-timed-text-markup-language">Timed Text Markup Language</a> content to either <a href="#terms-timed-text-markup-language">Timed Text Markup Language</a>
-or to another (arbitrary) content format. An example of the first is a processor that removes
-or rewrites TTML features so as to conform to a profile of TTML. An example of the latter is
-a processor that translates TTML into a completely different timed text format. Because this
-specification does not otherwise define a target profile or format for transformation processing,
-no further transformation semantics are defined by this specification.</p></dd><dt class="label"><a id="terms-undesignated-profile"></a>[undesignated profile]</dt><dd><p>A <a href="#terms-profile">profile</a> that is not associated with a <a href="#terms-profile-designator">profile designator</a>, and which is
-referred to implicitly in the context of the profile's definition. Also referred to as an <em>anonymous profile</em>.</p></dd><dt class="label"><a id="terms-valid-abstract-document-instance"></a>[valid abstract document instance]</dt><dd><p>An <a href="#terms-abstract-document-instance">abstract document instance</a> which has been assessed for validity
-and found to be valid as defined by <a href="#doctypes"><b>4 Document Types</b></a>.</p></dd><dt class="label"><a id="terms-viewport"></a>[viewport]</dt><dd><p>A logical, rectangular area with respect to which content is encoded or decoded for the purpose of presentation, where such area
-may be employed by or for the authoring or presentation of a <a href="#terms-related-media-object">related media object</a> or
-the <a href="#terms-root-container-region">root container region</a> and its constituent <a href="#terms-region">regions</a>.</p></dd><dt class="label"><a id="terms-viewport-target"></a>[viewport target]</dt><dd><p>An implied or explicit target or mapping of a <a href="#viewport">viewport</a> to some logical or physical entity, of which this
-specification identifies three such targets:
-<a href="#terms-display-target">display target</a>,
-<a href="#terms-display-region-target">display region target</a>, and
-<a href="#terms-related-media-object-region-target">related media object region target</a>.
-</p></dd></dl></div><div class="div2">
-<h3><a id="conventions"></a>2.3 Documentation Conventions</h3><p>Within normative prose in this specification, the words
-<em>may</em>, <em>should</em>, and <em>must</em> are
-defined as follows:</p><dl class="conformance-keywords"><dt class="label">may</dt><dd><p>Conforming documents and/or TTML processors are permitted to,
-but need not behave as described. </p></dd><dt class="label">should</dt><dd><p>Conforming documents and/or TTML processors are strongly
-recommended to, but need not behave as described.</p></dd><dt class="label">must</dt><dd><p>Conforming documents and/or TTML processors are required
-to behave as described; otherwise, they are in error. </p></dd></dl><p>If normative specification language takes an imperative form,
-then it is to be treated as if the term <span class="strong">must</span>
-applies. Furthermore, if normative language takes a declarative form,
-and this language is governed by <span class="strong">must</span>,
-then it is also to be treated as if the term <span class="strong">must</span>
-applies.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, the phrases "treat X as an error" and "consider X
-as an error" are to be read as mandatory requirements in the context of use. Similarly, if the specification
-prose is "X must apply", "X applies", or "X is mandatory", and "X" is further defined as "X is Y and Z",
-then, by transitive closure, this last declarative phrase is to be read as "Y is mandatory" and
-"Z is mandatory" in the context of use.</p></div><p>All normative syntactic definitions of XML representations and
-other related terms are depicted with a light yellow-orange background color
-and labeled as "XML Representation" or "Syntax Representation", such
-as in the following:</p><a id="elt-syntax-example"></a><table class="syntax"><caption>XML Representation – Element Information Item: example</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;example
-  <span class="reqattr">count</span> = <a href="http://www.w3.org/TR/xmlschema-2/#integer">xsd:integer</a>
-  size = (<em>large</em>|<em>medium</em>|<em>small</em>|<em><span class="deprecated">tiny</span></em>|<em><span class="obsoleted">micro</span></em>) : medium&gt;
-  <em>Content:</em> (all | any*)
-&lt;/example&gt;
-</pre></div>
-</td></tr></tbody></table><p>In an XML representation, bold-face attribute names (e.g. <span class="strong">count</span> above) indicate a required attribute
-information item, and the rest are optional. Where an attribute
-information item has an enumerated type definition, the values are
-shown separated by vertical bars, as for <code>size</code> above; if
-there is a default value, it is shown following a colon. Where an
-<a href="#terms-attribute-information-item">attribute information item</a> has a built-in simple type definition
-defined in <a href="#xsd-2">[XML Schema Part 2]</a>, a hyperlink to its definition
-therein is given.</p><p>In an XML representation, the expression <em>{any attribute not in default or any TT namespace}</em> applies
-only to namespace qualified attributes; unqualified attributes are not permitted unless explicitly defined in this specification.</p><p>An information item depicted with a <span class="deprecated">light yellow orange</span> background color is deprecated (e.g.,
-the <span class="deprecated">tiny</span> value of the <code>size</code> attribute shown above).
-An information item that is <span class="deprecated">deprecated</span> may but should not appear in a TTML document instance,
-and a validating processor should report a warning if it does appear.
-An information item depicted with a <span class="obsoleted">light magenta red</span> background color is obsoleted (e.g.,
-the <span class="obsoleted">micro</span> value of the <code>size</code> attribute shown above).
-An information item that is <span class="obsoleted">obsoleted</span> must not appear in a TTML document instance,
-and a validating processor should report an error if it does appear.
-These designations of an item
-are also explicitly called out in specification text.</p><p>The allowed content of the information item is shown as a grammar
-fragment, using the Kleene operators <code>?</code>, <code>*</code>
-and <code>+</code>. Each element name therein is a hyperlink to its
-own illustration.</p><p>The term linear white-space (LWSP) is to be interpreted as a non-empty sequence of
-SPACE (U+0020), TAB (U+0009), CARRIAGE RETURN (U+000D), or LINE FEED (U+000A),
-which corresponds to production [3] <code>S</code> as defined by <a href="#xml10">[XML 1.0]</a>.</p><p>All content of this specification that is not explicitly marked as
-non-normative is considered to be normative. If a section or appendix
-header contains the expression "Non-Normative", then the entirety
-of the section or appendix is considered non-normative.</p><p>All paragraphs marked as a <span class="strong">Note</span> are considered non-normative.</p><p>Example code fragments are depicted with a light blue-green
-background color and labeled as "Example Fragment", such as in
-the following:</p><a id="example-fragment-1"></a><table class="example"><caption>Example Fragment – Sample</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head&gt;
-    &lt;metadata/&gt;
-    &lt;styling/&gt;
-    &lt;layout/&gt;
-  &lt;/head&gt;
-  &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>Unless specified otherwise, the vocabulary defining sections of this specification define vocabulary in alphabetical order rather than logical order.</p></div></div><div class="div1">
-<h2><a id="conformance"></a>3 Conformance</h2><p>This section specifies the general conformance requirements for
-TTML documents and processors.</p><div class="div2">
-<h3><a id="conformance-content"></a>3.1 Document Conformance</h3><p>A <a href="#terms-timed-text-document-instance">timed text document instance</a> conforms to this specification if the following criteria are
-satisfied:</p><ol class="enumar"><li><p>When transporting a <a href="#terms-document-instance">document instance</a> in a <a href="#terms-document-interchange-context">document interchange context</a> in which a
-Media Type <a href="#media-types">[MIME Media Types]</a> identifies the content type of the interchanged <a href="#terms-document-instance">document instance</a>, then the specified media type is
-<code>application/ttml+xml</code> in conformance with <a href="#xml-media">[XML Media Types]</a> § 7, with which an optional
-<code>profile</code> parameter may appear, the value of which
-conforms to
-a profile designator as
-defined by
-<a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>.</p></li><li><p>The <a href="#terms-document-instance">document instance</a> is or can be represented as a <a href="#terms-reduced-xml-infoset">reduced xml infoset</a>
-as defined by <a href="#reduced-infoset"><b>B Reduced XML Infoset</b></a>.</p></li><li><p>The <a href="#terms-reduced-xml-infoset">reduced xml infoset</a> that
-corresponds to the <a href="#terms-document-instance">document instance</a> is or can
-be associated with one of the <a href="#terms-abstract-document-type">abstract document types</a> defined by
-<a href="#doctypes"><b>4 Document Types</b></a>.</p></li><li><p>The <a href="#terms-reduced-xml-infoset">reduced xml infoset</a> that corresponds to the <a href="#terms-document-instance">document instance</a> is a
-<a href="#terms-valid-abstract-document-instance">valid abstract document instance</a> of the associated
-<a href="#terms-abstract-document-type">abstract document type</a>.</p></li><li><p>The <a href="#terms-reduced-xml-infoset">reduced xml infoset</a> satisfies all additional mandatory syntactic and
-semantic constraints defined by this specification. In addition, this infoset
-should satisfy the web content accessibility guidelines specified by
-<a href="#wcag">[WCAG]</a>.</p></li></ol></div><div class="div2">
-<h3><a id="conformance-processor"></a>3.2 Processor Conformance</h3><div class="div3">
-<h4><a id="conformance-generic-processor"></a>3.2.1 Generic Processor Conformance</h4><table border="1" class="ednote" summary="Editorial note: Profile Processing"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Profile Processing</b></td><td align="right" valign="top">2014-05-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add requirement to invoke <span class="strong">abort if unsupported processor profile</span> procedure.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: Validation Processing"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Validation Processing</b></td><td align="right" valign="top">2014-05-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add requirement to invoke validation processing procedure. Add and use definition of 'validating processor'.</td></tr></table><p>A TTML <a href="#terms-content-processor">content processor</a> conforms to this specification if the following
-generic processor criteria are
-satisfied:</p><ol class="enumar"><li><p>The processor provides at least one mechanism for notionally
-instantiating a <a href="#terms-reduced-xml-infoset">reduced xml infoset</a>
-representation of a conformant <a href="#terms-document-instance">document instance</a>.</p></li><li><p>If a processor does or can perform validation of a candidate 
-<a href="#terms-document-instance">document instance</a>, then it provides at least one mechanism to
-implicitly or explicitly associate the
-<a href="#terms-reduced-xml-infoset">reduced xml infoset</a> representation
-of a conformant <a href="#terms-document-instance">document instance</a> with one of the
-<em>Abstract Document Types</em> defined by
-<a href="#doctypes"><b>4 Document Types</b></a>.</p></li><li><p>The processor does not <em>a priori</em> reject or abort the
-processing of a conformant <a href="#terms-document-instance">document instance</a>
-unless the processor does not support some required
-(mandatory) feature specified or implied by a TTML profile
-declared to apply to the <a href="#terms-document-instance">document instance</a>.</p></li><li><p>The processor supports all mandatory processing semantics defined by this specification.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The phrase <em>mandatory semantics</em> refers to all explicit use of the conformance
-key phrases <span class="strong">must</span> and <span class="strong">must not</span> as well as any
-declarative statement that can be reasonably inferred from such key phrases. For example, these
-mandatory semantics include support for all features marked as mandatory in <a href="#feature-support"><b>E.2 Feature Support</b></a>.</p></div></li><li><p>If the processor supports some optional processing semantics defined by this specification,
-then it does so in a manner consistent with the defined semantics.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The phrase <em>optional semantics</em> refers to all explicit use of the conformance
-key phrases <span class="strong">should</span>, <span class="strong">should not</span>,
-<span class="strong">may</span>, and <span class="strong">may not</span>,
-as well as any declarative statement that can be reasonably inferred from such key phrases. For example, these
-optional semantics include support for all features marked as optional in <a href="#feature-support"><b>E.2 Feature Support</b></a>.</p></div></li></ol></div><div class="div3">
-<h4><a id="conformance-transformation-processor"></a>3.2.2 Transformation Processor Conformance</h4><p>A TTML <a href="#terms-content-processor">content processor</a> is a conformant TTML <a href="#terms-transformation-processor">transformation processor</a> if
-the following criteria are satisfied:</p><ol class="enumar"><li><p>The processor satisfies all requirements specified by
-<a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a>.</p></li><li><p>The processor supports the TTML Transformation profile as specified
-by <a href="#profile-ttml2-transformation"><b>G.3 TTML2 Transformation Profile</b></a>.</p></li></ol><table border="1" class="ednote" summary="Editorial note: Mandatory Support for DFXP Transformation Profile"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Mandatory Support for DFXP Transformation Profile</b></td><td align="right" valign="top">2014-07-31</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Should we also require support for DFXP Transformation Profile?</td></tr></table></div><div class="div3">
-<h4><a id="conformance-presentation-processor"></a>3.2.3 Presentation Processor Conformance</h4><p>A TTML <a href="#terms-content-processor">content processor</a> is a conformant TTML <a href="#terms-presentation-processor">presentation processor</a> if
-the following criteria are satisfied:</p><ol class="enumar"><li><p>The processor satisfies all requirements specified by
-<a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a>.</p></li><li><p>The processor supports the TTML Presentation profile as specified
-by <a href="#profile-ttml2-presentation"><b>G.2 TTML2 Presentation Profile</b></a>.</p></li></ol><table border="1" class="ednote" summary="Editorial note: Mandatory Support for DFXP Presentation Profile"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Mandatory Support for DFXP Presentation Profile</b></td><td align="right" valign="top">2014-07-31</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Should we also require support for DFXP Presentation Profile?</td></tr></table></div></div><div class="div2">
-<h3><a id="claims"></a>3.3 Claims</h3><p>Any claim of compliance with respect to the conformance of a TTML <a href="#terms-document-instance">document instance</a> or
-<a href="#terms-content-processor">content processor</a> must make
-reference to an implementation compliance statement (ICS).</p><p>An implementation compliance statement must identify all mandatory
-and optional features of this specification that are satisfied by the
-document instance or the content processor implementation. In particular, the statement must
-identify the utilized or supported TTML vocabulary profile(s) as
-defined by <a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>, and, if a subset or
-superset profile is used or supported, then what features are excluded
-or included in the subset or superset profile.</p><p>A <a href="#terms-document-instance">document instance</a> for which a compliance claim is made
-must specify
-either (1)
-a <code>ttp:profile</code> attribute on its root
-<code>tt</code>
-element
-as defined by <a href="#profile-attribute-profile"><b>6.2.7 ttp:profile</b></a>
-or (2)
-a <code>ttp:profile</code> element as a child of the
-<code>head</code> element as defined by
-<a href="#profile-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>. In addition, it must specify a
-<code>ttp:version</code> attribute on its root <code>tt</code> element if it requires
-support for a <a href="#terms-feature">feature</a> not defined by <a href="#ttml1">[TTML1]</a>.</p></div></div><div class="div1">
-<h2><a id="doctypes"></a>4 Document Types</h2><p>This section defines the following TTML <em>Abstract Document Types</em>:</p><ul><li><p><a href="#ttml-content-doctype"><b>4.1 TTML Content Document Type</b></a></p></li><li><p><a href="#ttml-intermediate-doctype"><b>4.2 TTML Intermediate Document Type</b></a></p></li><li><p><a href="#ttml-profile-doctype"><b>4.3 TTML Profile Document Type</b></a></p></li></ul><p>Each <a href="#terms-abstract-document-type">abstract document type</a> consists of the following constraints:</p><ul><li><p>a non-empty collection of element types, where each element type consists of a name,
-a (possibly empty) collection of attributes, and a content specification</p></li><li><p>a non-empty collection of element types that may appear as the document element</p></li></ul><p>An <a href="#terms-abstract-document-instance">abstract document instance</a> may be assessed in terms of validity,
-and is considered to be a <a href="#terms-valid-abstract-document-instance">valid abstract document instance</a> if it
-satisfies the following condition: if after</p><ol class="enumar"><li><p>pruning all element information
-items whose names are not members of the collection of element types defined
-by the associated <a href="#terms-abstract-document-type">abstract document type</a>, then</p></li><li><p>pruning character
-information item children from any remaining element in case that all
-character children of the element denote XML whitespace characters and the element's type
-is defined as empty in the associated <a href="#terms-abstract-document-type">abstract document type</a>, and then</p></li><li><p>pruning all attribute
-information items having expanded names such that the namespace URI of the
-expanded names are not listed in <a href="#namespace-vocab-table"><b>Table 5-1 – Namespaces</b></a>,</p></li></ol><p>then the document element is one of the document
-element types permitted by the associated <a href="#terms-abstract-document-type">abstract document type</a>,
-the descendants of the document
-element satisfy their respective element type's content
-specifications, all required attributes are present, and the declared
-value of each attribute satisfies the type declared by the
-associated <a href="#terms-abstract-document-type">abstract document type</a>.</p><div class="issue"><p class="prefix"><a id="issue-362"></a><b>Issue (issue-362):</b></p><p class="prefix"><b>Attribute Forward Compabitility</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/362">http://www.w3.org/AudioVideo/TT/tracker/issues/362</a></p><p>Enhance step (3) to handle forward compatibility of new attributes introduced into TT namespaces.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>While a conformant processor may not <em>a priori</em> reject a
-conformant <a href="#terms-document-instance">document instance</a>, a given <a href="#terms-document-instance">document instance</a> may be
-constrained by the author or authoring tool to satisfy a more
-restrictive definition of validity.</p></div><div class="div2">
-<h3><a id="ttml-content-doctype"></a>4.1 TTML Content Document Type</h3><p>The TTML Content Document Type is an <a href="#terms-abstract-document-type">abstract document type</a> of a profile
-of the Timed Text Markup Language intended to be used for interchange among distribution systems. This document type
-is defined in terms of the element and attribute vocabulary specified in <a href="#vocabulary"><b>5 Vocabulary</b></a>.</p><p>This specification references two types of schemas that may be used to validate a superset/subset
-of <a href="#terms-timed-text-content-document-instance">timed text content document instances</a>:</p><ul><li><p><a href="#ttml-schema-rnc"><b>C.1 Relax NG Compact (RNC) Schema</b></a></p></li><li><p><a href="#ttml-schema-xsd"><b>C.2 XML Schema Definition (XSD) Schema</b></a></p></li></ul><p>The (root) document element of a TTML Content <a href="#terms-document-instance">document instance</a> must be a
-<code>tt</code> element, as defined by <a href="#document-structure-vocabulary-tt"><b>8.1.1 tt</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The schemas referenced by this specification do not validate all syntactic constraints
-defined by this specification, and, as such, represent a superset of conformant
-TTML Content. In particular, performing validation with one of the above
-referenced schemas may result in a <em>false positive</em> indication of validity.
-For example, both the RNC and XSD schemas specify
-that a <code>tts:fontFamily</code> attribute must
-satisfy the <code>xsd:string</code> XSD data type; however, this data type is a superset
-of the values permitted to be used with the <code>tts:fontFamily</code> attribute.</p><p>In addition, the RNC schema may produce a <em>false negative</em>
-indication of validity when using the <code>xml:id</code> attribute with an element in
-a foreign namespace, thus representing a subset of conformant TTML Content. This is
-due to a specific limitation in expressing wildcard patterns involving <code>xsd:ID</code>
-typed attributes in Relax NG schemas. Note that this specification defines the
-formal validity of a <a href="#terms-document-instance">document instance</a> to be based on an <a href="#terms-abstract-document-instance">abstract document instance</a> from
-which all foreign namespace elements and attributes have been removed. Therefore, the
-exceptional reporting of this false negative does not impact the formal assessment
-of <a href="#terms-document-instance">document instance</a> validity.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>A conforming <a href="#conformance-generic-processor">Generic Processor</a> is required to support the ingestion and processing
-of a <a href="#terms-timed-text-content-document">timed text content document</a>.</p></div></div><div class="div2">
-<h3><a id="ttml-intermediate-doctype"></a>4.2 TTML Intermediate Document Type</h3><p>The TTML Intermediate Document Type is an <a href="#terms-abstract-document-type">abstract document type</a> intended
-to be used to represent the content of a
-<a href="#terms-timed-text-content-document">timed text content document</a>
-in such a manner that all discrete animation, styling, and timing information is denoted in
-a non-hierarchical (flat), temporally linear manner. This document type is defined in terms of the element and attribute vocabulary
-specified in <a href="#isd"><b>I Intermediate Document Syntax</b></a> and <a href="#vocabulary"><b>5 Vocabulary</b></a>.</p><p>This specification references two types of schemas that may be used to validate
-<a href="#terms-timed-text-intermediate-document-instance">timed text intermediate document instances</a>:</p><ul><li><p><a href="#ttml-schema-rnc"><b>C.1 Relax NG Compact (RNC) Schema</b></a></p></li><li><p><a href="#ttml-schema-xsd"><b>C.2 XML Schema Definition (XSD) Schema</b></a></p></li></ul><p>The (root) document element of a TTML Intermediate Synchronic <a href="#terms-document-instance">document instance</a> must be an
-<code>isd:sequence</code> or <code>isd:isd</code> element, as defined by <a href="#isd"><b>I Intermediate Document Syntax</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A conforming <a href="#conformance-generic-processor">Generic Processor</a> is not required to support the ingestion or processing
-of a <a href="#terms-timed-text-intermediate-document">timed text intermediate document</a>.</p></div></div><div class="div2">
-<h3><a id="ttml-profile-doctype"></a>4.3 TTML Profile Document Type</h3><p>The TTML Profile Document Type is an <a href="#terms-abstract-document-type">abstract document type</a> intended
-to be used for defining and communicating constraints on the support or use of TTML features or extensions. This document type
-is defined in terms of the element and attribute vocabulary specified in <a href="#vocabulary"><b>5 Vocabulary</b></a>.</p><p>This specification references two types of schemas that may be used to validate
-<a href="#terms-timed-text-profile-document-instance">timed text profile document instances</a>:</p><ul><li><p><a href="#ttml-schema-rnc"><b>C.1 Relax NG Compact (RNC) Schema</b></a></p></li><li><p><a href="#ttml-schema-xsd"><b>C.2 XML Schema Definition (XSD) Schema</b></a></p></li></ul><p>The (root) document element of a TTML Profile <a href="#terms-document-instance">document instance</a> must be a
-<code>ttp:profile</code> element, as defined by <a href="#profile-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A conforming <a href="#conformance-generic-processor">Generic Processor</a> is recommended, but not required to support the ingestion or processing
-of a <a href="#terms-timed-text-profile-document">timed text profile document</a>. However, a <a href="#terms-content-processor">content processor</a>
-that claims to support the <code>http://www.w3.org/ns/ttml/feature/#profile</code> feature is required to support this (ingestion and processing of
-a <a href="#terms-timed-text-profile-document">timed text profile document</a>).</p></div></div></div><div class="div1">
-<h2><a id="vocabulary"></a>5 Vocabulary</h2><p>This section defines the
-namespaces, profiles, and vocabulary (as an element and attribute
-catalog) of the Timed Text Markup Language (TTML) as follows:</p><ul><li><p><a href="#vocabulary-namespaces"><b>5.1 Namespaces</b></a></p></li><li><p><a href="#vocabulary-profiling"><b>5.2 Profiling</b></a></p></li><li><p><a href="#vocabulary-overview"><b>5.3 Catalog</b></a></p></li></ul><div class="div2">
-<h3><a id="vocabulary-namespaces"></a>5.1 Namespaces</h3><p>The Timed Text Markup Language (TTML) employs a number of
-XML Namespaces <a href="#xmlns10">[XML Namespaces 1.0]</a> for elements and certain
-global attributes. The following table specifies this set of namespaces
-and indicates the default prefix used within this specification and the
-normative URI that denotes each namespace.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In a specific <a href="#terms-document-instance">document instance</a>, it is not required that the default
-prefixes shown below are used. Any prefix or namespace binding that satisfies the constraints
-of XML Namespaces <a href="#xmlns10">[XML Namespaces 1.0]</a>  may be used that is associated with the specified namespace URI.</p></div><a id="namespace-vocab-table"></a><table class="common"><caption>Table 5-1 – Namespaces</caption><col width="30%" span="1"><col span="1"><col span="1"><tbody><tr><th>Name</th><th>Prefix</th><th>Value</th></tr><tr><td>TT</td><td><code>tt:</code></td><td><code>http://www.w3.org/ns/ttml</code></td></tr><tr><td>TT Parameter</td><td><code>ttp:</code></td><td><code>http://www.w3.org/ns/ttml#parameter</code></td></tr><tr><td>TT Style</td><td><code>tts:</code></td><td><code>http://www.w3.org/ns/ttml#styling</code></td></tr><tr><td>TT Metadata</td><td><code>ttm:</code></td><td><code>http://www.w3.org/ns/ttml#metadata</code></td></tr><tr><td>TT Intermediate Synchronic Document</td><td><code>isd:</code></td><td><code>http://www.w3.org/ns/ttml#isd</code></td></tr><tr><td>TT Profile</td><td><em>none</em></td><td><code>http://www.w3.org/ns/ttml/profile/</code></td></tr><tr><td>TT Feature</td><td><em>none</em></td><td><code>http://www.w3.org/ns/ttml/feature/</code></td></tr><tr><td>TT Extension</td><td><em>none</em></td><td><code>http://www.w3.org/ns/ttml/extension/</code></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>If a reference to an element type is used in this specification and the name
-of the element type is not namespace qualified, then the TT Namespace applies.</p><p>If a reference to an attribute is used in this specification and the name
-of the attribute is not namespace qualified, then the attribute is implicitly qualified by
-the element type with which it is used. That is, the attribute resides in the so-called
-<a href="http://www.w3.org/TR/1999/REC-xml-names-19990114/#ns-breakdown"><em>per-element-type namespace partition</em></a>
-<a href="#nsoriginal">[NSOriginal]</a>, the members of which are interpreted in accordance with the definition of the element type on which they appear.</p><p>For certain namespaces defined above, the default prefix
-is specified as <em>none</em> if no XML vocabulary is defined in
-the namespace by this specification (nor expected to be defined in a
-future version of this specification). In such cases, the use of the
-namespace URI is for purposes other than defining XML vocabulary,
-e.g., for designating profiles, features, extensions and for
-dereferencing standard profile definitions.</p></div><p>All TTML Namespaces are <a href="http://www.w3.org/2001/tag/doc/namespaceState#namespacedef"><em>mutable</em></a>
-<a href="#nsstate">[NSState]</a>; all undefined names in these namespaces are reserved for future
-standardization by the W3C.</p></div><div class="div2">
-<h3><a id="vocabulary-profiling"></a>5.2 Profiling</h3><p>This section describes the TTML profiling sub-system and high level requirements that apply to this sub-system. At the end of this section
-appears a sub-section containing examples of profile specifications and examples of how these specifications are referenced and used.</p><div class="div3">
-<h4><a id="vocabulary-profile-introduction"></a>5.2.1 Introduction</h4><p><em>This sub-section is non-normative.</em></p><p>A given profile may be used by a Timed Text Markup Language content author for one of two functions: (1) to declare that a
-<a href="#terms-document-instance">document instance</a> adheres to a collection of constraints on what
-vocabulary is used and how it is used, or (2) to declare that a <a href="#terms-processor">processor</a> must satisfy certain conditions on how
-content is processed. The first of these functions is termed a <a href="#terms-content-profile">content profile</a>, while
-the second is termed a <a href="#terms-processor-profile">processor profile</a>.</p><p>A <a href="#terms-content-profile">content profile</a> is used to allow an author to declare, at authoring time,
-what constraints the author intends to apply to a <a href="#terms-document-instance">document instance</a>. Such a
-declaration permits downstream processors to perform content validation or verification, as well as to guide or limit subsequent
-transformation or editing of content in order to maintain adherence to an author specified content profile. In addition, a
-downstream processor may use a content profile declaration to perform an early determination of its ability to process the features
-implied by the content profile.</p><p>Content profiles are declared by using (1) the <a href="#parameter-attribute-contentProfiles"><code>ttp:contentProfiles</code></a>
-attribute on the root <code>tt</code> element, (2) one or more top-level <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a>
-elements of type <code>content</code>, or (3) a combination of these two mechanisms. If not declared, no content profile is implied.</p><p>A <a href="#terms-processor-profile">processor profile</a> is used to allow an author to declare, at authoring time,
-what processing must be supported when processing a <a href="#terms-document-instance">document instance</a>, such that, if a
-processor is not able to perform the indicated processing, then processing should be aborted. Such a declaration permits downstream
-processors to avoid processing content that cannot be processed in a manner that meets the requirements of the content author.</p><p>Processor profiles are declared by using (1) the <a href="#parameter-attribute-processorProfiles"><code>ttp:processorProfiles</code></a>
-attribute on the root <code>tt</code> element, (2) one or more <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a>
-elements of type <code>processor</code>, or (3) a combination of these two mechanisms.
-If not declared, a processor profile is inferred from a declared content profile or from a
-<a href="#terms-default-profile">default profile</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>It is not a requirement on a conformant <a href="#terms-document-instance">document instance</a> that a processor profile be internally
-declared by use of a <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element or internally referenced by a
-<a href="#parameter-attribute-processorProfiles"><code>ttp:processorProfiles</code></a> attribute. More specifically, it is
-permitted that the <a href="#terms-document-interchange-context">document
-interchange context</a> determines the applicable processor profile through private
-agreement, out-of-band protocol, or common use (between sender and receiver) of a processor profile defined
-by an external specification.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>It is intended that the <code>ttp:processorProfiles</code> attribute be used when
-the author wishes to reference one (or more) of the standard, predefined processor profiles of
-TTML Content, and does not wish to modify (by supersetting or subsetting)
-that profile. This attribute may also be used by an author to indicate the use
-of a non-standard profile, in which case the specified profile designator expresses
-a URI that denotes an externally defined <a href="#terms-profile-definition-document">profile definition document</a>.
-However, it is not required that a conformant TTML <a href="#terms-content-processor">content processor</a> be able
-to dereference such an externally specified profile definition.</p><p>In contrast, it is intended that the <code>ttp:profile</code> element be
-used when the author wishes to make use of a modified predefined profile or
-wishes to include in the <a href="#terms-document-instance">document instance</a> a non-standard profile definition
-not based upon one of the predefined profiles.</p><p>A predefined profile is supersetted by specifying some feature or extension to
-be <code>required</code> (mandatory) that was either not specified in the underlying, baseline
-profile or was specified as <code>optional</code> (voluntary) in the baseline profile.
-A predefined profile is subsetted by specifying some feature or extension to
-be <code>optional</code> (voluntary) that was specified as <code>required</code> (mandatory)
-in the underlying, baseline profile.</p><p>When a baseline profile is modified by subsetting, the resulting, derived profile
-is referred to as a <em>subtractive</em> profile; when modified by supersetting, the result
-is referred to as an <em>additive</em> profile.
-It is also possible to define a derived profile that is simultaneously subtractive
-and additive.</p></div><p>A content author is not limited to using a single profile, but may make reference to multiple profiles of either type, i.e.,
-multiple content profiles and/or multiple processor profiles. When multiple profiles are referenced, their respective specifications
-are combined to form a single effective content profile that applies to the document and a single effective processor profile
-that applies to a processor when processing the document. In addition, an author is not limited to making reference to externally
-defined profiles, but may define one or more profiles inline within a document.</p></div><div class="div3">
-<h4><a id="semantics-profile-examples"></a>5.2.2 Profile Examples</h4><p><em>This sub-section is non-normative.</em></p><table border="1" class="ednote" summary="Editorial note: More profile examples."><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: More profile examples.</b></td><td align="right" valign="top">2014-05-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add more examples depicting new profiling features defined in TTML2.</td></tr></table><p>An example of an author defined
-additive, derived profile of the TTML Presentation
-profile is shown
-below in <a href="#ttml-example-sub-profile"><b>Example Fragment – TTML Additive Profile</b></a>.</p><a id="ttml-example-sub-profile"></a><table class="example"><caption>Example Fragment – TTML Additive Profile</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
- &lt;head&gt;
-   &lt;profile use="ttml2-presentation" xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-     &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-       &lt;feature value="required"&gt;#fontStyle-italic&lt;/feature&gt;
-     &lt;/features&gt;
-   &lt;/profile&gt;
- &lt;/head&gt;
- &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the baseline profile is declared to be
-the TTML Presentation profile, which is then additively modified by making the
-<code>#fontStyle-italic</code> feature required (rather than
-optional as it is defined
-in <a href="#profile-ttml2-presentation"><b>G.2 TTML2 Presentation Profile</b></a>). Note also the resetting of the
-default XMLNS binding on the <code>profile</code> element to the TT Parameter Namespace.</p></div></div><div class="div3">
-<h4><a id="vocabulary-profile-designators"></a>5.2.3 Profile Designators</h4><table border="1" class="ednote" summary="Editorial note: Reference by designator to internally defined profile."><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Reference by designator to internally defined profile.</b></td><td align="right" valign="top">2014-05-26</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Handle case where a designator refers to an internally defined profile.</td></tr></table><p>A profile is referenced in one of two ways according to whether the profile is defined externally to the referring document or
-is defined inline within the referring document. When defined externally, a profile is referenced by means of a
-<a href="#terms-profile-designator">profile designator</a>. When defined internally (inline), a profile is referenced either implicitly
-or by means of <a href="#terms-profile-fragment-identifier">profile fragment identifier</a>.</p><table border="1" class="ednote" summary="Editorial note: Profile Fragment Identifiers."><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Profile Fragment Identifiers.</b></td><td align="right" valign="top">2014-05-26</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Update following to account for use of profile fragment identifier as a profile designator.</td></tr></table><p>A profile designator must adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17. If the profile designator is expressed as a relative URI,
-then it must be absolutized by using the TT Profile Namespace value as
-the base URI.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, if a profile designator is expressed as
-<code>ttml2-presentation</code>, then the absolutized profile designator
-would be
-<code>http://www.w3.org/ns/ttml/profile/ttml2-presentation</code>.</p></div><p>All profile designators which have the TT Profile Namespace as a prefix but are otherwise not listed in
-<a href="#profile-vocab-table"><b>Table 5-2 – Profiles</b></a> are reserved for future standardization, and must not appear in a conformant
-<a href="#terms-document-instance">document instance</a>. Nothwithstanding this constraint, a profile designator is not restricted to the set of designators enumerated
-in <a href="#profile-vocab-table"><b>Table 5-2 – Profiles</b></a>, but may be any URI that feasibly dereferences a TTML <a href="#terms-profile-definition-document">profile definition document</a>
-provided it does not use the TT Profile Namespace as a prefix.</p><div class="div4">
-<h5><a id="vocabulary-profile-standard-designators"></a>5.2.3.1 Standard Designators</h5><p>The Timed Text Markup Language (TTML) employs a number of
-standard, predefined profiles of its
-vocabulary and associated semantics.</p><p>The following table specifies this set of
-profiles, indicating
-a normative name
-and designator for each
-predefined profile,
-and where each of these profiles is formally elaborated in
-<a href="#standard-profiles"><b>G Standard Profiles</b></a>, in <a href="#ttml1">[TTML1]</a>,
-or in another TTWG specification.</p><a id="profile-vocab-table"></a><table class="common"><caption>Table 5-2 – Profiles</caption><col width="25%" span="1"><col span="1"><tbody><tr><th>Name</th><th>Designator</th></tr><tr><td>DFXP Full</td><td><code>http://www.w3.org/ns/ttml/profile/dfxp-full</code></td></tr><tr><td>DFXP Presentation</td><td><code>http://www.w3.org/ns/ttml/profile/dfxp-presentation</code></td></tr><tr><td>DFXP Transformation</td><td><code>http://www.w3.org/ns/ttml/profile/dfxp-transformation</code></td></tr><tr><td>SDP US</td><td><code>http://www.w3.org/ns/ttml/profile/sdp-us</code></td></tr><tr><td>TTML2 Full</td><td><code>http://www.w3.org/ns/ttml/profile/ttml2-full</code></td></tr><tr><td>TTML2 Presentation</td><td><code>http://www.w3.org/ns/ttml/profile/ttml2-presentation</code></td></tr><tr><td>TTML2 Transformation</td><td><code>http://www.w3.org/ns/ttml/profile/ttml2-transformation</code></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>For definitions of the DFXP profiles, see <a href="#ttml1">[TTML1]</a>. For definition of the SDP US profile, see <a href="#sdpus">[SDP US]</a>.</p></div></div></div><div class="div3">
-<h4><a id="semantics-profile-semantics"></a>5.2.4 Profile Semantics</h4><div class="div4">
-<h5><a id="semantics-profile-state"></a>5.2.4.1 Profile State Object Concepts</h5><p>This section defines a number of conceptual state objects used by subsequently defined algorithms (procedures and functions). It is not required that an
-implementation create such objects in the form specified here, but may use any convenient, internal representation that represents equivalent information.</p><dl><dt class="label"><a id="semantics-profile-state-profile-specification"></a>[profile specification]</dt><dd><p>a <a href="#semantics-profile-state-profile-specification"><span class="strong">profile specification</span></a>
-represents the following internal state information that corresponds with
-a <a href="#profile-vocabulary-feature"><code>ttp:feature</code></a> or <a href="#profile-vocabulary-extension"><code>ttp:extension</code></a>
-element</p><dl><dt class="label"><a id="semantics-profile-state-profile-specification-designator"></a>designator</dt><dd><p>an absolute xsd:anyURI denoting a feature or extension designator depending upon the <em><code>type</code></em></p></dd><dt class="label"><a id="semantics-profile-state-profile-specification-type"></a>type</dt><dd><p><code>feature|extension</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-specification-value"></a>value</dt><dd><p><code>optional|required|prohibited</code></p></dd></dl></dd><dt class="label"><a id="semantics-profile-state-combined-profile-specification-set"></a>[combined profile specification set]</dt><dd><p>a <a href="#semantics-profile-state-combined-profile-specification-set"><span class="strong">combined profile specification set</span></a>
-represents the following internal state information
-that corresponds with a set of <a href="#semantics-profile-state-profile-specification"><span class="strong">profile specifications</span></a>,
-additionally recording the constituent
-profiles from which these specifications were obtained (or derived)</p><dl><dt class="label"><a id="semantics-profile-state-combined-profile-specification-set-constituents"></a>constituents</dt><dd><p>ordered list of absolute profile designators, where each designator denotes a constituent profile, i.e.,
-a profile from which this combined profile specification set is composed</p></dd><dt class="label"><a id="semantics-profile-state-combined-profile-specification-set-specifications"></a>specifications</dt><dd><p>ordered list of <a href="#semantics-profile-state-profile-specification"><span class="strong">profile specifications</span></a></p></dd></dl></dd><dt class="label"><a id="semantics-profile-state-empty-profile-specification-set"></a>[empty profile specification set]</dt><dd><p>a <a href="#semantics-profile-state-combined-profile-specification-set"><span class="strong">combined profile specification set</span></a> which 
-<a href="#semantics-profile-state-combined-profile-specification-set-constituents"><span class="strong">constituents</span></a> and
-<a href="#semantics-profile-state-combined-profile-specification-set-specifications"><span class="strong">specifications</span></a> fields are empty sets</p></dd><dt class="label"><a id="semantics-profile-state-profile"></a>[profile]</dt><dd><p>a <a href="#semantics-profile-state-profile"><span class="strong">profile</span></a> represents the following internal state information
-that corresponds with a <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element, whether specified explicitly or implied</p><dl><dt class="label"><a id="semantics-profile-state-profile-designator"></a>designator</dt><dd><p>an absolute profile designator that is associated with (and uniquely labels) this profile</p></dd><dt class="label"><a id="semantics-profile-state-profile-type"></a>type</dt><dd><p><code>content|processor</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-combine"></a>combine</dt><dd><p><code>leastRestrictive|mostRestrictive|replace</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-use"></a>use</dt><dd><p>either <code>null</code> or an absolute profile designator denoting a profile that serves as the baseline profile for this profile</p></dd><dt class="label"><a id="semantics-profile-state-profile-constituents"></a>constituents</dt><dd><p>if profile is a <a href="#terms-nesting-profile">nesting profile</a>, then an ordered list of absolute profile designators, where each designator denotes a
-constituent <a href="#terms-nested-profile">nested profile</a>; otherwise, <code>null</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-specifications"></a>specifications</dt><dd><p>if profile is a <a href="#terms-non-nesting-profile">non-nesting profile</a>, then an ordered list of
-<a href="#semantics-profile-state-profile-specification"><span class="strong">profile specifications</span></a>; otherwise, <code>null</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-combined-specification-set"></a>combined specification set</dt><dd><p>a <a href="#semantics-profile-state-combined-profile-specification-set"><span class="strong">combined profile specification set</span></a> that
-represents the results of combining the specifications specified or referenced by this profile</p></dd></dl></dd></dl></div><div class="div4">
-<h5><a id="semantics-content-profile-processing"></a>5.2.4.2 Content Profile Semantics</h5><table border="1" class="ednote" summary="Editorial note: Validation Processing"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Validation Processing</b></td><td align="right" valign="top">2014-05-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add validation processing procedures.</td></tr></table><dl><dt class="label"><a id="semantics-procedure-construct-effective-content-profile"></a>[construct effective content profile]</dt><dd><p>Every TTML <a href="#terms-document-instance">document instance</a> is associated with an
-<a href="#terms-effective-content-profile">effective content profile</a> which may be used by
-a <a href="#terms-content-processor">content processor</a> to perform any (or all) of the following:</p><ol class="enumar"><li><p>infer an effective processor profile;</p></li><li><p>perform validation processing on the <a href="#terms-document-instance">document instance</a>;</p></li><li><p>constrain transformation processing on the <a href="#terms-document-instance">document instance</a>
-in order to maintain content profile invariants.</p></li></ol><p>The <a href="#terms-effective-content-profile">effective content profile</a> is determined according to the
-<a href="#semantics-procedure-construct-effective-content-profile"><span class="strong">construct effective content profile</span></a> procedure
-defined as follows:</p><ol class="enumar"><li><p>if a <code>ttp:contentProfiles</code> attribute is specified on the root <code>tt</code> element, then</p><ol class="enumla"><li><p>if the <code>ttp:contentProfiles</code> attribute is specified using the <code>all(...)</code> function syntax or
-using no function syntax, i.e., as only a list of designators, then the
-<a href="#terms-effective-content-profile">effective content profile</a> is the combined profile specification set
-produced by combining the combined profile specification sets of the designated profiles, where the <code>mostRestrictive</code>
-content profile combination method applies;</p></li><li><p>otherwise, if the <code>ttp:contentProfiles</code> attribute is specified using the <code>any(...)</code> function syntax, then the
-<a href="#terms-effective-content-profile">effective content profile</a> is the combined profile specification set
-produced by combining the combined profile specification sets of the designated profiles, where the <code>leastRestrictive</code>
-content profile combination method applies;</p></li></ol></li><li><p>otherwise, if one or more <a href="#terms-top-level-profile">top-level</a> <a href="#terms-content-profile">content profiles</a>
-are defined, then the
-<a href="#terms-effective-content-profile">effective content profile</a> is the combined profile specification set
-produced by combining the combined profile specification sets of all such
-<a href="#terms-top-level-profile">top-level</a> <a href="#terms-content-profile">content profiles</a>, where the
-content profile combination method specified by (or the default value of) the <code>ttp:contentProfileCombination</code>
-attribute on the root <code>tt</code> element applies;
-</p></li><li><p>otherwise, the <a href="#terms-effective-content-profile">effective content profile</a> is <code>null</code>;</p></li></ol></dd></dl></div><div class="div4">
-<h5><a id="semantics-processor-profile-processing"></a>5.2.4.3 Processor Profile Semantics</h5><dl><dt class="label"><a id="semantics-procedure-abort-if-unsupported-processor-profile"></a>[abort if unsupported processor profile]</dt><dd><ol class="enumar"><li><p>set <em>EPP</em> to the <a href="#terms-effective-processor-profile">effective processor profile</a> obtained by performing the
-<a href="#semantics-procedure-construct-effective-processor-profile"><span class="strong">construct effective processor profile</span></a> procedure;</p></li><li><p>for each profile specification <em>S</em> in the combined profile specification set of <em>EPP</em>, perform the following steps:</p><ol class="enumla"><li><p>if the <span class="strong">value</span> field of <em>S</em> is <code>required</code>, and the <a href="#terms-content-processor">content processor</a>
-does not support <em>S</em>, then abort processing of the <a href="#terms-document-instance">document instance</a> unless overridden
-by the end-user or some implementation specific parameter traceable to an end-user or to a user or system configuration setting;</p></li></ol></li></ol></dd><dt class="label"><a id="semantics-procedure-construct-effective-processor-profile"></a>[construct effective processor profile]</dt><dd><p>Every TTML <a href="#terms-document-instance">document instance</a> is associated with an
-<a href="#terms-effective-processor-profile">effective processor profile</a> which is used by
-a <a href="#terms-content-processor">content processor</a> to determine whether it meets the
-minimum processing requirements signaled by the content author, and if not, then must abort further
-processing unless overridden by the end-user or an implementation specific parameter traceable to
-an end-user or to a user or system configuration setting.
-The <a href="#terms-effective-processor-profile">effective processor profile</a> is determined according to the
-<a href="#semantics-procedure-construct-effective-processor-profile"><span class="strong">construct effective processor profile</span></a> procedure
-defined as follows:</p><ol class="enumar"><li><p>if a <code>ttp:processorProfiles</code> attribute is specified on the root <code>tt</code> element, then</p><ol class="enumla"><li><p>if the <code>ttp:processorProfiles</code> attribute is specified using the <code>all(...)</code> function syntax or
-using no function syntax, i.e., as only a list of designators, then the
-<a href="#terms-effective-processor-profile">effective processor profile</a> is the combined profile specification set
-produced by combining the combined profile specification sets of the designated profiles, where the <code>mostRestrictive</code>
-processor profile combination method applies;</p></li><li><p>otherwise, if the <code>ttp:processorProfiles</code> attribute is specified using the <code>any(...)</code> function syntax,
-then, for each designated profile, the 
-<a href="#terms-effective-processor-profile">effective processor profile</a> is the combined profile specification set
-of the first profile in the list of designated profiles that is supported by the
-<a href="#terms-content-processor">content processor</a>;</p></li></ol></li><li><p>otherwise, if one or more <a href="#terms-top-level-profile">top-level</a> <a href="#terms-processor-profile">processor profiles</a>
-are defined, then the
-<a href="#terms-effective-processor-profile">effective processor profile</a> is the combined profile specification set
-produced by combining the combined profile specification sets of all such
-<a href="#terms-top-level-profile">top-level</a> <a href="#terms-processor-profile">processor profiles</a>, where the
-processor profile combination method specified by (or the default value of) the <code>ttp:processorProfileCombination</code>
-attribute on the root <code>tt</code> element applies;
-</p></li><li><p>otherwise, if a <code>ttp:profile</code> attribute is specified on the root <code>tt</code> element, then the
-<a href="#terms-effective-processor-profile">effective processor profile</a> is the combined profile specification set
-of the profile designated by this attribute;
-</p></li><li><p>otherwise, the <a href="#terms-effective-processor-profile">effective processor profile</a> is the
-result of performing the <a href="#semantics-procedure-construct-inferred-processor-profile"><span class="strong">construct inferred processor profile</span></a>
-procedure;</p></li></ol></dd><dt class="label"><a id="semantics-procedure-construct-inferred-processor-profile"></a>[construct inferred processor profile]</dt><dd><ol class="enumar"><li><p>set <em>ECP</em> to the <a href="#terms-effective-content-profile">effective content profile</a>;</p></li><li><p>if <em>ECP</em> is not <code>null</code>, then perform the following steps:</p><ol class="enumla"><li><p>if the computed value of the <code>ttp:inferProcessorProfileSource</code> parameter is <code>combine</code>, then
-the <a href="#terms-inferred-processor-profile">inferred processor profile</a> is the result of applying the
-<a href="#semantics-procedure-infer-processor-profile"><span class="strong">infer processor profile</span></a> function
-to the combined profile specification set of <em>ECP</em>;</p></li><li><p>otherwise, if the computed value of the <code>ttp:inferProcessorProfileSource</code> parameter is <code>first</code>, then
-the <a href="#terms-inferred-processor-profile">inferred processor profile</a> is the first inferred processor profile, <em>IPP</em>, produced by applying the
-<a href="#semantics-procedure-infer-processor-profile"><span class="strong">infer processor profile</span></a> function
-to the combined profile specification set of each constituent of <em>ECP</em> such that
-<em>IPP</em> is supported by the <a href="#terms-content-processor">content processor</a>;</p></li></ol></li><li><p>otherwise, the <a href="#terms-inferred-processor-profile">inferred processor profile</a> is the
-result of performing the <a href="#semantics-procedure-construct-default-processor-profile"><span class="strong">construct default processor profile</span></a>
-procedure;</p></li></ol></dd><dt class="label"><a id="semantics-procedure-infer-processor-profile"></a>[infer processor profile](content profile <em>CP</em>)</dt><dd><ol class="enumar"><li><p>initialize inferred processor profile <em>IPP</em> to the empty combined profile specification set;</p></li><li><p>for each profile specification, <em>S</em>, in the combined profile specification set of content profile <em>CP</em>:</p><ol class="enumla"><li><p>map content profile specification <em>S</em> to processor profile specification <em>S'&nbsp;</em> according to the computed
-value of the <code>ttp:inferPresentationProfileMethod</code> parameter and <a href="#infer-processor-profile-method-table"><b>Table 6-2 – Infer Processor Profile Method</b></a>;</p></li><li><p>add <em>S'&nbsp;</em> to the combined profile specification set of <em>IPP</em>;</p></li></ol></li><li><p>return <em>IPP</em> as the inferred processor profile;</p></li></ol></dd><dt class="label"><a id="semantics-procedure-construct-default-processor-profile"></a>[construct default processor profile]</dt><dd><ol class="enumar"><li><p>if the <a href="#terms-document-interchange-context">document interchange context</a> is associated with a
-<a href="#terms-processor-profile">processor profile</a> or with a <a href="#terms-content-profile">content profile</a>
-from which a <a href="#terms-processor-profile">processor profile</a> can be inferred, then the
-<a href="#terms-default-processor-profile">default processor profile</a> is that <a href="#terms-processor-profile">processor profile</a>;</p></li><li><p>otherwise, if the <a href="#terms-content-processor">content processor</a> is primarily characterized as a
-<a href="#terms-presentation-processor">presentation processor</a>, then:</p><ol class="enumla"><li><p>if the <a href="#parameter-attribute-version"><code>ttp:version</code></a> attribute is not specified on the root <code>tt</code> element or
-if the computed value of its parameter property is <code>1</code> (one), then the <a href="#terms-default-processor-profile">default processor profile</a> is
-the <a href="#semantics-profile-state-profile">profile</a> constructed by interning the DFXP Presentation profile
-(<code>http://www.w3.org/ns/ttml/profile/dfxp-presentation</code>);</p></li><li><p>otherwise,
-if the computed value of the <a href="#parameter-attribute-version"><code>ttp:version</code></a> parameter property is <code>2</code> (two),
-the <a href="#terms-default-processor-profile">default processor profile</a> is
-the <a href="#semantics-profile-state-profile">profile</a> constructed by interning the TTML2 Presentation profile
-(<code>http://www.w3.org/ns/ttml/profile/ttml2-presentation</code>);</p></li><li><p>otherwise,
-the <a href="#terms-default-processor-profile">default processor profile</a> is
-the <a href="#semantics-profile-state-profile">profile</a> constructed by interning a TTML presentation profile
-associated with the computed value of <a href="#parameter-attribute-version"><code>ttp:version</code></a>,
-if one is known, or, if not known, then the most recently defined presentation profile;</p></li></ol></li><li><p>otherwise, if the <a href="#terms-content-processor">content processor</a> is primarily characterized as a
-<a href="#terms-transformation-processor">transformation processor</a>, then:</p><ol class="enumla"><li><p>if the <a href="#parameter-attribute-version"><code>ttp:version</code></a> attribute is not specified on the root <code>tt</code> element or
-if the computed value of its parameter property is <code>1</code> (one), then the <a href="#terms-default-processor-profile">default processor profile</a> is
-the <a href="#semantics-profile-state-profile">profile</a> constructed by interning the DFXP Transformation profile
-(<code>http://www.w3.org/ns/ttml/profile/dfxp-transformation</code>);</p></li><li><p>otherwise,
-if the computed value of the <a href="#parameter-attribute-version"><code>ttp:version</code></a> parameter property is <code>2</code> (two),
-the <a href="#terms-default-processor-profile">default processor profile</a> is
-the <a href="#semantics-profile-state-profile">profile</a> constructed by interning the TTML2 Transformation profile
-(<code>http://www.w3.org/ns/ttml/profile/ttml2-transformation</code>);</p></li><li><p>otherwise,
-the <a href="#terms-default-processor-profile">default processor profile</a> is
-the <a href="#semantics-profile-state-profile">profile</a> constructed by interning a TTML transformation profile
-associated with the computed value of <a href="#parameter-attribute-version"><code>ttp:version</code></a>,
-if one is known, or, if not known, then the most recently defined TTML transformation profile;</p></li></ol></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>A <a href="#terms-content-processor">content processor</a> intended to be used with
-one or more distinct versions of TTML greater than version 2 (TTML2) may choose a
-<a href="#terms-default-processor-profile">default processor profile</a> based upon
-a future version of a TTML presentation or transformation profile.</p></div></dd></dl></div></div></div><div class="div2">
-<h3><a id="vocabulary-overview"></a>5.3 Catalog</h3><p>The vocabulary of the Timed Text Markup Language (TTML) is
-defined in the following major catalogs (divisions of vocabulary):</p><ul><li><p><a href="#core-vocabulary-overview"><b>5.3.1 Core Catalog</b></a></p></li><li><p><a href="#extension-vocabulary-overview"><b>5.3.2 Extension Catalog</b></a></p></li></ul><p>The core catalog defines the baseline, core vocabulary of TTML,
-and, in particular, the vocabulary of TTML Content. The extension catalog
-serves as a placeholder for extensions to the core vocabulary defined
-by TTML.</p><div class="div3">
-<h4><a id="core-vocabulary-overview"></a>5.3.1 Core Catalog</h4><p>The core vocabulary catalog is intended to satisfy the needs of
-TTML while providing a baseline vocabulary for future profiles. This vocabulary
-is divided into distinct categories, specified in detail
-in the following sections:</p><ul><li><p><a href="#profile"><b>6 Profile</b></a></p></li><li><p><a href="#parameter"><b>7 Parameter</b></a></p></li><li><p><a href="#content"><b>8 Content</b></a></p></li><li><p><a href="#embedded-content"><b>9 Embedded Content</b></a></p></li><li><p><a href="#styling"><b>10 Styling</b></a></p></li><li><p><a href="#layout"><b>11 Layout</b></a></p></li><li><p><a href="#timing"><b>12 Timing</b></a></p></li><li><p><a href="#animation"><b>13 Animation</b></a></p></li><li><p><a href="#metadata"><b>14 Metadata</b></a></p></li></ul><p>The core element vocabulary specified for use with a <a href="#terms-document-instance">document instance</a> is enumerated in
-<a href="#element-vocab-table"><b>Table 5-3 – Element Vocabulary</b></a>.</p><a id="element-vocab-table"></a><table class="common"><caption>Table 5-3 – Element Vocabulary</caption><col width="25%" span="1"><col span="1"><tbody><tr><th>Module</th><th>Elements</th></tr><tr id="element-vocab-type-animation"><td>
-Animation
-</td><td>
-<a href="#animation-vocabulary-animate">animate</a>,
-<a href="#animation-vocabulary-animation">animation</a>,
-<a href="#animation-vocabulary-set">set</a>
-</td></tr><tr id="element-vocab-type-audio"><td>
-Audio
-</td><td>
-<a href="#data-vocabulary-audio">audio</a>
-</td></tr><tr id="element-vocab-type-content"><td>
-Content
-</td><td>
-<a href="#document-structure-vocabulary-body">body</a>,
-<a href="#content-vocabulary-br">br</a>,
-<a href="#content-vocabulary-div">div</a>,
-<a href="#content-vocabulary-p">p</a>,
-<a href="#content-vocabulary-span">span</a>
-</td></tr><tr id="element-vocab-type-data"><td>
-Data
-</td><td>
-<a href="#data-vocabulary-data">chunk</a>,
-<a href="#data-vocabulary-data">data</a>,
-<a href="#data-vocabulary-resources">resources</a>,
-<a href="#data-vocabulary-source">source</a>
-</td></tr><tr id="element-vocab-type-document"><td>
-Document
-</td><td>
-<a href="#document-structure-vocabulary-tt">tt</a>
-</td></tr><tr id="element-vocab-type-font"><td>
-Font
-</td><td>
-<a href="#data-vocabulary-font">font</a>
-</td></tr><tr id="element-vocab-type-head"><td>
-Head
-</td><td>
-<a href="#document-structure-vocabulary-head">head</a>
-</td></tr><tr id="element-vocab-type-image"><td>
-Image
-</td><td>
-<a href="#data-vocabulary-image">image</a>
-</td></tr><tr id="element-vocab-type-layout"><td>
-Layout
-</td><td>
-<a href="#layout-vocabulary-layout">layout</a>,
-<a href="#layout-vocabulary-region">region</a>
-</td></tr><tr id="element-vocab-type-metadata"><td>
-Metadata
-</td><td>
-<a href="#metadata-vocabulary-metadata">metadata</a>
-</td></tr><tr id="element-vocab-type-metadata-items"><td>
-Metadata Items
-</td><td>
-<a href="#metadata-vocabulary-actor">ttm:actor</a>,
-<a href="#metadata-vocabulary-agent">ttm:agent</a>,
-<a href="#metadata-vocabulary-copyright">ttm:copyright</a>,
-<a href="#metadata-vocabulary-desc">ttm:desc</a>,
-<a href="#metadata-vocabulary-item">ttm:item</a>,
-<a href="#metadata-vocabulary-name">ttm:name</a>,
-<a href="#metadata-vocabulary-title">ttm:title</a>
-</td></tr><tr id="element-vocab-type-profile"><td>Profile</td><td>
-<a href="#profile-vocabulary-features">ttp:features</a>,
-<a href="#profile-vocabulary-feature">ttp:feature</a>,
-<a href="#profile-vocabulary-extensions">ttp:extensions</a>,
-<a href="#profile-vocabulary-extension">ttp:extension</a>,
-<a href="#profile-vocabulary-profile">ttp:profile</a>
-</td></tr><tr id="element-vocab-type-styling"><td>
-Styling
-</td><td>
-<a href="#styling-vocabulary-initial">initial</a>,
-<a href="#styling-vocabulary-styling">styling</a>,
-<a href="#styling-vocabulary-style">style</a>
-</td></tr></tbody></table><p></p><p>Element vocabulary groups that are used in defining content models
-for TTML element types are enumerated in <a href="#element-vocab-group-table"><b>Table 5-4 – Element Vocabulary Groups</b></a>.</p><a id="element-vocab-group-table"></a><table class="common"><caption>Table 5-4 – Element Vocabulary Groups</caption><col width="25%" span="1"><col span="1"><tbody><tr><th>Group</th><th>Elements</th></tr><tr id="element-vocab-group-animation"><td>
-Animation.class
-</td><td>
-<a href="#animation-vocabulary-animate">animate</a> |
-<a href="#animation-vocabulary-set">set</a>
-</td></tr><tr id="element-vocab-group-block"><td>
-Block.class
-</td><td>
-<a href="#content-vocabulary-div">div</a> |
-<a href="#content-vocabulary-p">p</a>
-</td></tr><tr id="element-vocab-group-data"><td>
-Data.class
-</td><td>
-<a href="#data-vocabulary-data">data</a>
-</td></tr><tr id="element-vocab-group-embedded"><td>
-Embedded.class
-</td><td>
-<a href="#data-vocabulary-audio">audio</a>,
-<a href="#data-vocabulary-image">image</a>
-</td></tr><tr id="element-vocab-group-font"><td>
-Font.class
-</td><td>
-<a href="#data-vocabulary-font">font</a>
-</td></tr><tr id="element-vocab-group-inline"><td>
-Inline.class
-</td><td>
-<a href="#content-vocabulary-span">span</a> |
-<a href="#content-vocabulary-span">br</a> |
-<code>#PCDATA</code>
-</td></tr><tr><td>
-Layout.class
-</td><td id="element-vocab-group-layout">
-<a href="#layout-vocabulary-region">region</a>
-</td></tr><tr id="element-vocab-group-metadata"><td>
-Metadata.class
-</td><td>
-<a href="#metadata-vocabulary-metadata">metadata</a> |
-<a href="#metadata-vocabulary-copyright">ttm:agent</a> |
-<a href="#metadata-vocabulary-copyright">ttm:copyright</a> |
-<a href="#metadata-vocabulary-desc">ttm:desc</a> |
-<a href="#metadata-vocabulary-desc">ttm:item</a> |
-<a href="#metadata-vocabulary-title">ttm:title</a>
-</td></tr><tr id="element-vocab-group-profile"><td>Profile.class</td><td><a href="#profile-vocabulary-profile">ttp:profile</a></td></tr></tbody></table><p></p><p>The attribute vocabulary specified for use with the core vocabulary
-catalog is enumerated in
-<a href="#attribute-vocab-table"><b>Table 5-5 – Attribute Vocabulary</b></a>.</p><a id="attribute-vocab-table"></a><table class="common"><caption>Table 5-5 – Attribute Vocabulary</caption><col width="25%" span="1"><col span="1"><tbody><tr><th>Module</th><th>Attributes</th></tr><tr id="attribute-vocab-group-animation-binding"><td>
-Animation Binding Attribute
-</td><td>
-<a href="#animation-attribute-animate">animate</a>
-</td></tr><tr id="attribute-vocab-group-core"><td>
-Core Attributes
-</td><td>
-<a href="#content-attribute-xml-id">xml:id</a>,
-<a href="#content-attribute-xml-lang">xml:lang</a>,
-<a href="#content-attribute-xml-space">xml:space</a>
-</td></tr><tr id="attribute-vocab-group-data"><td>
-Data Attributes
-</td><td>
-<a href="#embedded-content-attribute-encoding">encoding</a>,
-<a href="#embedded-content-attribute-format">format</a>,
-<a href="#embedded-content-attribute-src">src</a>,
-<a href="#embedded-content-attribute-type">type</a>
-</td></tr><tr id="attribute-vocab-group-layout-binding"><td>
-Layout Binding Attribute
-</td><td>
-<a href="#layout-attribute-region">region</a>
-</td></tr><tr id="attribute-vocab-group-metadata"><td>
-Metadata Attributes
-</td><td>
-<a href="#metadata-attribute-agent">ttm:agent</a>,
-<a href="#metadata-attribute-role">ttm:role</a>
-</td></tr><tr id="attribute-vocab-group-parameters"><td>
-Parameter Attributes
-</td><td>
-<a href="#parameter-attribute-cellResolution">ttp:cellResolution</a>,
-<a href="#parameter-attribute-clockMode">ttp:clockMode</a>,
-<a href="#parameter-attribute-dropMode">ttp:dropMode</a>,
-<a href="#parameter-attribute-frameRate">ttp:frameRate</a>,
-<a href="#parameter-attribute-frameRateMultiplier">ttp:frameRateMultipler</a>,
-<a href="#parameter-attribute-markerMode">ttp:markerMode</a>,
-<a href="#parameter-attribute-mediaDuration">ttp:mediaDuration</a>,
-<a href="#parameter-attribute-mediaOffset">ttp:mediaOffset</a>,
-<a href="#parameter-attribute-pixelAspectRatio">ttp:pixelAspectRatio</a>,
-<a href="#parameter-attribute-storageAspectRatio">ttp:storageAspectRatio</a>,
-<a href="#parameter-attribute-subFrameRate">ttp:subFrameRate</a>,
-<a href="#parameter-attribute-tickRate">ttp:tickRate</a>,
-<a href="#parameter-attribute-timeBase">ttp:timeBase</a>,
-</td></tr><tr id="attribute-vocab-group-profile"><td>
-Profile Attributes
-</td><td>
-<a href="#profile-attribute-contentProfiles">ttp:contentProfiles</a>,
-<a href="#profile-attribute-contentProfileCombination">ttp:contentProfileCombination</a>,
-<a href="#profile-attribute-inferProcessorProfileMethod">ttp:inferProcessorProfileMethod</a>,
-<a href="#profile-attribute-inferProcessorProfileSource">ttp:inferProcessorProfileSource</a>,
-<a href="#profile-attribute-permitFeatureNarrowing">ttp:permitFeatureNarrowing</a>,
-<a href="#profile-attribute-permitFeatureWidening">ttp:permitFeatureWidening</a>,
-<a href="#profile-attribute-profile">ttp:profile</a>,
-<a href="#profile-attribute-processorProfiles">ttp:processorProfiles</a>,
-<a href="#profile-attribute-processorProfileCombination">ttp:processorProfileCombination</a>,
-<a href="#profile-attribute-validation">ttp:validation</a>,
-<a href="#profile-attribute-validationAction">ttp:validationAction</a>,
-<a href="#profile-attribute-version">ttp:version</a>
-</td></tr><tr id="attribute-vocab-group-style-binding"><td>
-Style Binding Attribute
-</td><td>
-<a href="#style-attribute-style">style</a>
-</td></tr><tr id="attribute-vocab-group-style"><td>
-Styling Attributes
-</td><td>
-<a href="#style-attribute-backgroundColor">tts:backgroundColor</a>,
-<a href="#style-attribute-backgroundImage">tts:backgroundImage</a>,
-<a href="#style-attribute-backgroundPosition">tts:backgroundPosition</a>,
-<a href="#style-attribute-backgroundRepeat">tts:backgroundRepeat</a>,
-<a href="#style-attribute-border">tts:border</a>,
-<a href="#style-attribute-color">tts:color</a>,
-<a href="#style-attribute-direction">tts:direction</a>,
-<a href="#style-attribute-display">tts:display</a>,
-<a href="#style-attribute-displayAlign">tts:displayAlign</a>,
-<a href="#style-attribute-extent">tts:extent</a>,
-<a href="#style-attribute-fontFamily">tts:fontFamily</a>,
-<a href="#style-attribute-fontKerning">tts:fontKerning</a>,
-<a href="#style-attribute-fontSelectionStrategy">tts:fontSelectionStrategy</a>,
-<a href="#style-attribute-fontShear">tts:fontShear</a>,
-<a href="#style-attribute-fontSize">tts:fontSize</a>,
-<a href="#style-attribute-fontStyle">tts:fontStyle</a>,
-<a href="#style-attribute-fontVariantPosition">tts:fontVariantPosition</a>,
-<a href="#style-attribute-fontWeight">tts:fontWeight</a>,
-<a href="#style-attribute-height">tts:height</a>,
-<a href="#style-attribute-letterSpacing">tts:letterSpacing</a>,
-<a href="#style-attribute-lineHeight">tts:lineHeight</a>,
-<a href="#style-attribute-opacity">tts:opacity</a>,
-<a href="#style-attribute-origin">tts:origin</a>,
-<a href="#style-attribute-overflow">tts:overflow</a>,
-<a href="#style-attribute-padding">tts:padding</a>,
-<a href="#style-attribute-position">tts:position</a>,
-<a href="#style-attribute-ruby">tts:ruby</a>,
-<a href="#style-attribute-rubyAlign">tts:rubyAlign</a>,
-<a href="#style-attribute-rubyOffset">tts:rubyOffset</a>,
-<a href="#style-attribute-rubyPosition">tts:rubyPosition</a>,
-<a href="#style-attribute-showBackground">tts:showBackground</a>,
-<a href="#style-attribute-textAlign">tts:textAlign</a>,
-<a href="#style-attribute-textCombine">tts:textCombine</a>,
-<a href="#style-attribute-textDecoration">tts:textDecoration</a>,
-<a href="#style-attribute-textEmphasis">tts:textEmphasis</a>,
-<a href="#style-attribute-textOrientation">tts:textOrientation</a>,
-<a href="#style-attribute-textOutline">tts:textOutline</a>,
-<a href="#style-attribute-textShadow">tts:textShadow</a>,
-<a href="#style-attribute-unicodeBidi">tts:unicodeBidi</a>,
-<a href="#style-attribute-visibility">tts:visibility</a>,
-<a href="#style-attribute-width">tts:width</a>,
-<a href="#style-attribute-wrapOption">tts:wrapOption</a>,
-<a href="#style-attribute-writingMode">tts:writingMode</a>,
-<a href="#style-attribute-zIndex">tts:zIndex</a>
-</td></tr><tr id="attribute-vocab-group-timing"><td>
-Timing Attributes
-</td><td>
-<a href="#timing-attribute-begin">begin</a>,
-<a href="#timing-attribute-dur">dur</a>,
-<a href="#timing-attribute-end">end</a>,
-<a href="#timing-attribute-timeContainer">timeContainer</a>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>Only those attributes defined as either (1) global, i.e., namespace qualified, or
-(2) shared element-specific, i.e., not namespace qualified but shared across multiple
-element types, are listed in <a href="#attribute-vocab-table"><b>Table 5-5 – Attribute Vocabulary</b></a> above.
-</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>All vocabulary defined by TTML consistently makes use of
-the so-called <em>lowerCamelCase</em> naming convention. In some cases, this results in the
-change of a name when the name was based upon another specification
-that used a different naming convention.</p></div></div><div class="div3">
-<h4><a id="extension-vocabulary-overview"></a>5.3.2 Extension Catalog</h4><p>The extension vocabulary catalog is intended for use by future
-profiles of TTML, and is not further defined
-by this version of this specification.</p><p>In addition to standardized extension vocabulary, a conforming 
-<a href="#terms-document-instance">document instance</a> may contain arbitrary namespace qualified
-elements that reside in any namespace other than those namespaces
-defined for use with this specification. Furthermore, a conforming 
-<a href="#terms-document-instance">document instance</a> may contain arbitrary namespace qualified
-attributes on TTML defined vocabulary where such attributes reside in
-any namespace other than those defined for use with this
-specification.</p></div></div></div><div class="div1">
-<h2><a id="profile"></a>6 Profile</h2><p>This section specifies the <em>profile</em> matter of the
-core vocabulary catalog, where profile matter is to be understood as information that expresses requirements or optionality related to authoring or processing
-a <a href="#terms-timed-text-content-document">timed text content document</a>.</p><div class="div2">
-<h3><a id="profile-element-vocabulary"></a>6.1 Profile Element Vocabulary</h3><p>The following elements, all defined in the TT Parameter
-Namespace, specify parametric information that applies to a <a href="#terms-document-instance">document instance</a>
-or <a href="#terms-content-processor">content processor</a>:</p><ul><li><p><a href="#profile-vocabulary-profile"><b>6.1.1 ttp:profile</b></a></p></li><li><p><a href="#profile-vocabulary-features"><b>6.1.2 ttp:features</b></a></p></li><li><p><a href="#profile-vocabulary-feature"><b>6.1.3 ttp:feature</b></a></p></li><li><p><a href="#profile-vocabulary-extensions"><b>6.1.4 ttp:extensions</b></a></p></li><li><p><a href="#profile-vocabulary-extension"><b>6.1.5 ttp:extension</b></a></p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>The sub-sections of this section are ordered logically (from highest to lowest level construct).</p></div><div class="div3">
-<h4><a id="profile-vocabulary-profile"></a>6.1.1 ttp:profile</h4><p>The <code>ttp:profile</code> element is used to specify a
-<a href="#terms-processor-profile">processor profile</a> or a
-<a href="#terms-content-profile">content profile</a>.
-A <a href="#terms-processor-profile">processor profile</a> specifies a
-collection of required (mandatory) and optional (voluntary) features and extensions that must or
-may be supported by a <a href="#terms-content-processor">content processor</a> in order to process a
-<a href="#terms-document-instance">document instance</a> that makes (or may make) use of such features and
-extensions.
-A <a href="#terms-content-profile">content profile</a> specifies a
-collection of prohibited, required, and optional features and extensions that, respectively,
-must not, must, and may be present in a <a href="#terms-document-instance">document instance</a> that declares its
-adherence to the profile.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The difference between a <em>feature</em> and an
-<em>extension</em> is where it is defined and how it is labeled:
-if defined in this specification (or a future revision thereof) and
-labeled with a feature designation in <a href="#features"><b>E Features</b></a>, then
-it is considered to be a feature; if defined in another specification
-and labeled there with an extension designation, then it is considered
-to be an extension. In general, features are expected to be defined by
-the W3C standards process, while extensions are expected to be defined by
-third parties.</p></div><p>This specification defines two distinct contexts of use for the <code>ttp:profile</code> element:</p><ul><li><p>as a child of the <code>head</code> element or a <code>ttp:profile</code> element within a TTML <a href="#terms-document-instance">document instance</a>;</p></li><li><p>as the root element of a TTML <a href="#terms-profile-definition-document">profile definition document</a>
-instance;</p></li></ul><p>When a <code>ttp:profile</code> element appears within a TTML <a href="#terms-document-instance">document instance</a>,
-its purpose is to express authorial intentions about (1) which
-features and extensions must or may be supported by a recipient
-content processor in order to process that document or (2) which features and extensions must not, must, or may be
-included or otherwise used in that <a href="#terms-document-instance">document instance</a>.</p><p>When a <code>ttp:profile</code> element is used by a TTML <a href="#terms-profile-definition-document">profile definition document</a> instance,
-it serves to publish a machine
-readable specification of a specific TTML profile that may be referenced by TTML <a href="#terms-document-instance">document instances</a>.
-This specification defines a number of standard <em>Profile Definition Documents</em> in
-<a href="#standard-profiles"><b>G Standard Profiles</b></a>.</p><p>The <code>ttp:profile</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group, followed by either (1)
-zero or more <code>ttp:features</code> elements followed by
-zero or more <code>ttp:extensions</code> elements or (2)
-zero or more <code>ttp:profile</code> elements.
-When a <code>ttp:profile</code> element contains a child <code>ttp:profile</code> element, then the child is referred to as
-a <a href="#terms-nested-profile">nested profile</a> and the parent is referred to as a <a href="#terms-nesting-profile">nesting profile</a>;
-otherwise it is referred to as a <a href="#terms-non-nesting-profile">non-nesting profile</a>.</p><a id="elt-syntax-profile"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttp:profile</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:profile
-  combine = (leastRestrictive|mostRestrictive|replace) : replace
-  designator = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  type = (processor|content) : processor
-  use = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, ((<a href="#profile-vocabulary-features">ttp:features</a>*, <a href="#profile-vocabulary-extensions">ttp:extensions</a>*)|<a href="#profile-vocabulary-profile">ttp:profile</a>*)
-&lt;/ttp:profile&gt;
-</pre></div>
-</td></tr></tbody></table><p>The <code>type</code> attribute is used to determine whether a profile is a
-<a href="#terms-processor-profile">processor profile</a> or a
-<a href="#terms-content-profile">content profile</a>. If not specified,
-the profile is considered to be a <a href="#terms-processor-profile">processor profile</a>.
-If a <code>ttp:profile</code> element references a <a href="#terms-baseline-profile">baseline profile</a> or a
-<a href="#terms-nested-profile">nested profile</a>, then the type of the referenced profile must be the same as the type of the referencing profile. For
-example, a <code>ttp:profile</code> element that defines a <a href="#terms-processor-profile">processor profile</a> may only make reference to other
-<a href="#terms-processor-profile">processor profiles</a>, and may not reference a <a href="#terms-content-profile">content profile</a>.</p><p>The <code>combine</code> attribute is used to specify how
-feature or extension specifications are combined in the case that
-multiple specifications apply to the same feature or extension, respectively.</p><p>If the value of the <code>combine</code> attribute is <code>replace</code>, then a
-lexically subsequent feature or extension specification replaces a lexically prior
-specification, where specification elements are ordered as follows:</p><ol class="enumar"><li><p>specifications defined by a <a href="#terms-baseline-profile">baseline profile</a> referenced by a <code>use</code>
-attribute;</p></li><li><p>specifications defined by descendant <code>ttp:profile</code> elements in post-order
-traversal order;</p></li><li><p>specifications defined as descendant <code>ttp:feature</code> or <code>ttp:extension</code>
-elements in post-order traversal order.</p></li></ol><p>If the value is <code>leastRestrictive</code>, then the least restrictive specification value applies;
-if the value is <code>mostRestrictive</code>, then the most restrictive specification value
-applies. The order of restrictiveness is as follows (from least to most):
-<em>optional</em>, <em>required</em>, <em>prohibited</em>.</p><p>If the <code>combine</code> attribute is not specified, then replacement semantics apply.</p><p>If specified, the <code>designator</code> attribute must (1) adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17 and (2) express an absolute URI that denotes a profile designator in
-accordance with <a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>. A <code>designator</code> attribute may
-be specified on a <code>ttp:profile</code> element that appears in a TTML
-<a href="#terms-document-instance">document instance</a>, and, if not specified,
-the defined profile is considered to be an undesignated profile.
-A <code>designator</code> attribute should
-be specified on a <code>ttp:profile</code> element that appears in a TTML
-<a href="#terms-profile-definition-document">profile definition document</a> instance,
-and, if not specified, the defining context (e.g., an external specification) must specify
-a designator in its accompanying definition text.</p><p>If specified, the <code>use</code> attribute must adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, and, furthermore, must denote a profile designator in
-accordance with <a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>. In this case,
-the profile designator must refer to (1) a standard, predefined
-<a href="#terms-profile-definition-document">profile definition document</a> as defined by <a href="#profile"><b>6 Profile</b></a>,
-or (2) a feasibly dereferenceable resource representing a valid <em>Profile Definition
-Document</em> instance. In either case, the referenced profile serves as the
-<a href="#terms-baseline-profile">baseline profile</a> of the specifying <code>ttp:profile</code> element.</p><p>If the <code>use</code> attribute is not specified, then the <a href="#terms-baseline-profile">baseline profile</a>
-of the <code>ttp:profile</code> element must be considered to be
-the empty (null) profile, i.e., a profile definition containing no
-feature or extension specifications.</p><p>The combined specification set <em>CSS</em> of features and extensions of a profile <em>P</em>
-is determined according to the following ordered rules, where merging a specification <em>S</em>
-into <em>CSS</em> entails applying a combination method in accordance with the specified
-(or default) value of the <code>combine</code> attribute, and where merging a combined specification set <em>CSS'&nbsp;</em> into
-<em>CSS</em> entails merging each ordered specification of <em>CSS'&nbsp;</em> into <em>CSS</em>:</p><ol class="enumar"><li><p>initialize <em>CSS</em> to the empty set;</p></li><li><p>if a <code>use</code> attribute is present, then merge
-the combined specification set of the referenced <a href="#terms-baseline-profile">baseline profile</a> into <em>CSS</em>;</p></li><li><p>for each <code>ttp:profile</code> child of the <em>P</em>,
-using a post-order traversal, merge the combined specification set of the child profile
-into <em>CSS</em>;</p></li><li><p>for each <code>ttp:feature</code> and <code>ttp:extension</code> child of the <code>ttp:profile</code> element,
-using a post-order traversal, merge the feature or extension specification
-into <em>CSS</em>.</p></li></ol><p>A conformant TTML processor is not required to be able to
-dereference a <a href="#terms-profile-definition-document">profile definition document</a> that is not one of the
-standard, predefined profiles defined by <a href="#standard-profiles"><b>G Standard Profiles</b></a>.  Furthermore,
-a conformant TTML processor may make use of a built-in, static
-form of each standard, predefined profile so as not to require
-dereferencing a network resource.</p><p>If a TTML processor is unable to dereference a non-standard
-<a href="#terms-profile-definition-document">profile definition document</a>, then it must not further process the
-document without the presence of an explicit override from an end-user
-or some implementation specific parameter traceable to an end-user or
-to a user or system configuration setting. If a TTML processor aborts
-processing of a <a href="#terms-document-instance">document instance</a> due to the inability to
-reference a non-standard <a href="#terms-profile-definition-document">profile definition document</a>, then some
-end-user notification should be given unless the end-user or system
-has disabled such a notification, or if the processor does not permit
-or entail the intervention of an end-user.</p><p>The <code>ttp:profile</code> element is illustrated by the following example.</p><a id="profile-vocabulary-profile-example-1"></a><table class="example"><caption>Example Fragment – ttp:profile</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:profile use="ttml2-presentation"&gt;
-  &lt;ttp:features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;ttp:feature&gt;#text-outline&lt;/ttp:feature&gt;
-  &lt;/ttp:features&gt;
-&lt;/ttp:profile&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the TTML presentation profile is used as the
-baseline profile. This baseline profile is then supersetted (thus
-creating an additive derived profile) by requiring support for
-<code>#text-outline</code> feature.</p></div></div><div class="div3">
-<h4><a id="profile-vocabulary-features"></a>6.1.2 ttp:features</h4><p>The <code>ttp:features</code> element is a container element used to group
-infomation about feature support and usage requirements.</p><p>The <code>ttp:features</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group, followed by
-zero or more <code>ttp:feature</code> elements.</p><a id="elt-syntax-features"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttp:features</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:features
-  xml:base = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a> : <em>TT Feature Namespace</em>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#profile-vocabulary-feature">ttp:feature</a>*
-&lt;/ttp:features&gt;
-</pre></div>
-</td></tr></tbody></table><p>If specified, the <code>xml:base</code>
-attribute must (1) adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, (2) express an absolute URI that
-adheres to <a href="#xmlbase">[XML Base]</a> and,
-(3) express a feature namespace as defined by
-<a href="#feature-designations"><b>E.1 Feature Designations</b></a>. If not specified, the
-<code>xml:base</code> attribute's default
-value applies, which is the TT Feature Namespace.</p><p>The <code>xml:base</code> attribute is
-used to permit the abbreviation of feature designation URIs expressed
-by child <code>ttp:feature</code> elements.</p></div><div class="div3">
-<h4><a id="profile-vocabulary-feature"></a>6.1.3 ttp:feature</h4><p>The <code>ttp:feature</code> element is used to specify
-infomation about support and usage requirements for a particular feature.</p><a id="elt-syntax-feature"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttp:feature</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:feature
-  extends = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  restricts = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  value = (optional|required|<span class="obsoleted">use</span>|prohibited) : <em>see prose below</em>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttp:feature&gt;
-</pre></div>
-</td></tr></tbody></table><p>The children of the <code>ttp:feature</code> element must express a non-empty
-sequence of <a href="#terms-character-information-item">character information items</a> the concatenation of which adheres to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17.</p><p>If specified, the <code>extends</code> attribute and/or the <code>restricts</code>
-attribute must (1) adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, and
-(2) express a feature designation as defined by
-<a href="#feature-designations"><b>E.1 Feature Designations</b></a>.</p><p>The <code>extends</code> attribute may be used to indicate that the feature being defined
-is, from either (or both) a syntactic or (and) semantic perspective, a proper superset of the
-feature referenced by the <code>extends</code> attribute.
-The <code>restricts</code> attribute may be used to indicate that the feature being defined
-is, from either (or both) a syntactic or (and) semantic perspective, a proper subset of the
-feature referenced by the <code>restricts</code> attribute.
-If an <code>extends</code> attribute is specified, then a <code>restricts</code> attribute must
-not be specified on a <code>ttp:feature</code> element; likewise, if a <code>restricts</code> attribute
-is specified, then an <code>extends</code> attribute must not be specified.</p><p>If the URI expressed by (1) the content of the <code>ttp:feature</code>
-element, (2) the <code>extends</code> attribute, or (3) the <code>restricts</code> attribute
-is a relative URI, then, when combined with the
-feature namespace value expressed by the
-<code>xml:base</code> attribute of the
-nearest ancestor <code>ttp:features</code> element, it must express an
-absolute URI.  In either case (original absolute URI or resulting
-absolutized URI), the URI expressed by the <code>ttp:feature</code>
-element must further adhere to the syntax of a feature designation as
-defined by <a href="#feature-designations"><b>E.1 Feature Designations</b></a>, and, furthermore,
-the specific designation that appears in this URI, i.e., the portion of the feature designation
-that starts with the fragment identifier separator '#', must
-be defined by this specification or some published version thereof (that
-has achieved REC status).</p><p>If the URI expressed by the content of the <code>ttp:feature</code> element,
-by the <code>extends</code> attribute, or by the <code>restricts</code> attribute
-is a relative URI, then an <code>xml:base</code> attribute should be
-specified on the nearest ancestor <code>ttp:features</code> element.</p><p>The <code>value</code> attribute specifies constraints on support for or use of
-the designated feature according to the profile type.</p><p>If the profile is a <a href="#terms-processor-profile">processor profile</a>
-then the following semantics apply:</p><ul><li><p>
-if the value of the <code>value</code> attribute
-is <code>optional</code>, then a processor may but need
-not implement or otherwise support the feature in order to process the document;
-</p></li><li><p>if the value is <code>required</code>, then perform the following steps:</p><ol class="enumar"><li><p>if the feature is implemented or otherwise supported by a processor, then continue processing
-the document;</p></li><li><p>otherwise, if
-(1) the <code>extends</code> attribute is specified on the root <code>tt</code> element,
-(2) the value of the <code>extends</code> attribute designates a feature that is implemented or otherwise supported by
-a processor, and
-(3) the computed value of the <a href="#profile-attribute-permitFeatureNarrowing"><code>ttp:permitFeatureNarrowing</code></a>
-profile property of the root <code>tt</code> element is not <code>false</code>,
-then continue processing the document;</p></li><li><p>otherwise, if
-(1) the <code>restricts</code> attribute is specified on the root <code>tt</code> element,
-(2) the value of the <code>restricts</code> attribute designates a feature that is implemented or otherwise supported by
-a processor, and
-(3) the computed value of the <a href="#profile-attribute-permitFeatureWidening"><code>ttp:permitFeatureWidening</code></a>
-profile property of the root <code>tt</code> element is not <code>false</code>,
-then continue processing the document;</p></li><li><p>otherwise, abort processing the document unless overridden by the end-user or some implementation specific parameter
-traceable to an end-user or to a user or system configuration setting.</p></li></ol></li><li><p>
-if the value attribute is not specified, then the feature specification
-must be interpreted as if the value <code>required</code> were specified;
-</p></li></ul><p>If the profile is a <a href="#terms-content-profile">content profile</a>
-then the following semantics apply:</p><ul><li><p>
-if the value of the <code>value</code> attribute
-is <code>optional</code>, then the feature may but need not appear in a document that
-claims conformance with that profile;
-</p></li><li><p>
-if the value of the <code>value</code> attribute
-is <code>required</code>, then the feature must appear in a document that
-claims conformance with that profile;
-</p></li><li><p>
-if the value of the <code>value</code> attribute
-is <code>prohibited</code>, then the feature must not appear in a document that
-claims conformance with that profile;
-</p></li><li><p>
-if the value attribute is not specified, then the feature specification
-must be interpreted as if the value <code>optional</code> were specified;
-</p></li></ul><p>The value <span class="obsoleted"><code>use</code></span> of the <code>value</code> attribute is <span class="obsoleted">obsoleted</span>. If it
-appears in a profile specification, then it must be interpreted as if <code>required</code>
-had been specified.</p><p>If some defined (i.e., standardized) or otherwise well known feature is not specified by
-a <code>ttp:feature</code> element in a content profile, then it must be interpreted as if the feature were specified
-with the <code>value</code> attribute equal to <code>optional</code>. However, if not specified in a processor profile, no claim
-about support or absence of support for the feature is implied.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In particular, if some feature is not present in a content profile definition, then
-it is not to be interpreted as meaning the use of that feature (in a <a href="#terms-document-instance">document instance</a>)
-is disallowed or otherwise prohibited. If a feature is intended to be disallowed by a content profile, then
-it should be specified using the <code>prohibited</code> value.</p></div><p>If a <a href="#terms-document-instance">document instance</a> makes use of a feature defined by
-<a href="#feature-designations"><b>E.1 Feature Designations</b></a> and if the intended use of the
-document requires the recognition and processing of that feature, then
-the document must include a <em>required</em> feature specification in one of its declared or
-referenced profiles.</p><p>The <code>ttp:feature</code> element is illustrated by the following example.</p><a id="profile-vocabulary-feature-example-1"></a><table class="example"><caption>Example Fragment – ttp:feature</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:profile use="http://www.w3.org/ns/ttml/profile/ttml2-presentation"&gt;
-  &lt;ttp:features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    <span class="strong">&lt;ttp:feature value="required"&gt;#fontStyle-italic&lt;/ttp:feature&gt;</span>
-    <span class="strong">&lt;ttp:feature value="required"&gt;#textDecoration-under&lt;/ttp:feature&gt;</span>
-    <span class="strong">&lt;ttp:feature value="prohibited"&gt;#textOutline-blurred&lt;/ttp:feature&gt;</span>
-  &lt;/ttp:features&gt;
-&lt;/ttp:profile&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the TTML presentation profile is used as the
-baseline profile. This baseline profile is then modified by three
-<code>ttp:feature</code> elements in order to (1)
-superset the baseline profile (since neither
-<code>#fontStyle-italic</code> nor <code>#textDecoration-under</code>
-are required by the TTML presentation profile), and
-(2) prohibit use of the <code>#textOutline-blurred</code> feature
-(which is optional in the TTML presentation profile).</p><p>The effect of this example is to express authorial intentions that
-italic font style and text underlining must be
-supported, and that text outline blurring must not be used by a document.</p></div></div><div class="div3">
-<h4><a id="profile-vocabulary-extensions"></a>6.1.4 ttp:extensions</h4><p>The <code>ttp:extensions</code> element is a container element used to group
-infomation about extension support and usage requirements.</p><p>The <code>ttp:extensions</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group, followed by
-zero or more <code>ttp:extension</code> elements.</p><a id="elt-syntax-extensions"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttp:extensions</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:extensions
-  xml:base = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a> : <em>TT Extension Namespace</em>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#profile-vocabulary-extension">ttp:extension</a>*
-&lt;/ttp:extensions&gt;
-</pre></div>
-</td></tr></tbody></table><p>If specified, the <code>xml:base</code>
-attribute must (1) adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, (2) express an absolute URI that
-adheres to <a href="#xmlbase">[XML Base]</a> and,
-(3) express an extension namespace as defined by
-<a href="#extension-designations"><b>F.1 Extension Designations</b></a>. If not specified, the
-<code>xml:base</code> attribute's default
-value applies, which is the TT Extension Namespace.</p><p>The <code>xml:base</code> attribute is
-used to permit the abbreviation of feature designation URIs expressed
-by child <code>ttp:extension</code> elements.</p></div><div class="div3">
-<h4><a id="profile-vocabulary-extension"></a>6.1.5 ttp:extension</h4><p>The <code>ttp:extension</code> element is used to specify
-infomation about support and usage requirements for a particular extension.</p><a id="elt-syntax-extension"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttp:extension</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:extension
-  extends = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  restricts = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  value = (optional|required|<span class="obsoleted">use</span>|prohibited) : <em>see prose below</em>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttp:extension&gt;
-</pre></div>
-</td></tr></tbody></table><p>The children of the <code>ttp:extension</code> element must express a non-empty
-sequence of <a href="#terms-character-information-item">character information items</a> the concatenation of which adheres to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17.</p><p>If specified, the <code>extends</code> attribute and/or the <code>restricts</code>
-attribute must (1) adhere to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, and
-(2) express a feature designation or extension designation as defined by
-<a href="#feature-designations"><b>E.1 Feature Designations</b></a> or <a href="#extension-designations"><b>F.1 Extension Designations</b></a>, respectively.</p><p>The <code>extends</code> attribute may be used to indicate that the extension being defined
-is, from either (or both) a syntactic or (and) semantic perspective, a proper superset of the
-feature or extension referenced by the <code>extends</code> attribute.
-The <code>restricts</code> attribute may be used to indicate that the extension being defined
-is, from either (or both) a syntactic or (and) semantic perspective, a proper subset of the
-feature or extension referenced by the <code>restricts</code> attribute.
-If an <code>extends</code> attribute is specified, then a <code>restricts</code> attribute must
-not be specified on a <code>ttp:extension</code> element; likewise, if a <code>restricts</code> attribute
-is specified, then an <code>extends</code> attribute must not be specified.</p><p>If the URI expressed by (1) the content of the <code>ttp:extension</code>
-element, (2) the <code>extends</code> attribute, or (3) the <code>restricts</code> attribute
-is a relative URI, then, when combined with the
-extension namespace value expressed by the
-<code>xml:base</code> attribute of the
-nearest ancestor <code>ttp:extensions</code> element, it must express an
-absolute URI.  In either case (original absolute URI or resulting
-absolutized URI), the URI expressed by the <code>ttp:extension</code>
-element must further adhere to the syntax of an extension designation as
-defined by <a href="#extension-designations"><b>F.1 Extension Designations</b></a>,
-while the URI expressed by the <code>extends</code> attribute and/or the
-<code>restricts</code> attribute must adhere to the syntax of a feature designation
-or an extension designation as defined by <a href="#feature-designations"><b>E.1 Feature Designations</b></a> or
-<a href="#extension-designations"><b>F.1 Extension Designations</b></a>, respectively.</p><p>If the URI expressed by the content of the <code>ttp:extension</code> element,
-by the <code>extends</code> attribute, or by the <code>restricts</code> attribute
-is a relative URI, then an <code>xml:base</code> attribute should be
-specified on the nearest ancestor <code>ttp:extensions</code> element.</p><p>The <code>value</code> attribute specifies constraints on support for or use of
-the designated extension according to the profile type.</p><p>If the profile is a <a href="#terms-processor-profile">processor profile</a>
-then the following semantics apply:</p><ul><li><p>
-if the value of the <code>value</code> attribute
-is <code>optional</code>, then a processor may but need
-not implement or otherwise support the extension in order to process the document;
-</p></li><li><p>if the value is <code>required</code>, then perform the following steps:</p><ol class="enumar"><li><p>if the extension is implemented or otherwise supported by a processor, then continue processing
-the document;</p></li><li><p>otherwise, if
-(1) the <code>extends</code> attribute is specified on the root <code>tt</code> element,
-(2) the value of the <code>extends</code> attribute designates an extension that is implemented or otherwise supported by
-a processor, and
-(3) the computed value of the <a href="#profile-attribute-permitFeatureNarrowing"><code>ttp:permitFeatureNarrowing</code></a>
-profile property of the root <code>tt</code> element is not <code>false</code>,
-then continue processing the document;</p></li><li><p>otherwise, if
-(1) the <code>restricts</code> attribute is specified on the root <code>tt</code> element,
-(2) the value of the <code>restricts</code> attribute designates an extension that is implemented or otherwise supported by
-a processor, and
-(3) the computed value of the <a href="#profile-attribute-permitFeatureWidening"><code>ttp:permitFeatureWidening</code></a>
-profile property of the root <code>tt</code> element is not <code>false</code>,
-then continue processing the document;</p></li><li><p>otherwise, abort processing the document unless overridden by the end-user or some implementation specific parameter
-traceable to an end-user or to a user or system configuration setting.</p></li></ol></li><li><p>
-if the value attribute is not specified, then the extension specification
-must be interpreted as if the value <code>required</code> were specified;
-</p></li></ul><p>If the profile is a <a href="#terms-content-profile">content profile</a>
-then the following semantics apply:</p><ul><li><p>
-if the value of the <code>value</code> attribute
-is <code>optional</code>, then the extension may but need not appear in a document that
-claims conformance with that profile;
-</p></li><li><p>
-if the value of the <code>value</code> attribute
-is <code>required</code>, then the extension must appear in a document that
-claims conformance with that profile;
-</p></li><li><p>
-if the value of the <code>value</code> attribute
-is <code>prohibited</code>, then the extension must not appear in a document that
-claims conformance with that profile;
-</p></li><li><p>
-if the value attribute is not specified, then the extension specification
-must be interpreted as if the value <code>optional</code> were specified;
-</p></li></ul><p>The value <span class="obsoleted"><code>use</code></span> of the <code>value</code> attribute is <span class="obsoleted">obsoleted</span>. If it
-appears in a profile specification, then it must be interpreted as if <code>required</code>
-had been specified.</p><p>If some well known extension is not specified by
-a <code>ttp:extension</code> element in a content profile, then it must be interpreted as if the extension were specified
-with the <code>value</code> attribute equal to <code>optional</code>. However, if not specified in a processor profile, no claim
-about support or absence of support for the extension is implied.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In particular, if some extension is not present in a content profile definition, then
-it is not to be interpreted as meaning the use of that extension (in a <a href="#terms-document-instance">document instance</a>)
-is disallowed or otherwise prohibited. If an extension is intended to be disallowed by a content profile, then
-it should be specified using the <code>prohibited</code> value.</p></div><p>If a <a href="#terms-document-instance">document instance</a> makes use
-of an extension designatable by <a href="#extension-designations"><b>F.1 Extension Designations</b></a> and if the intended use of the document
-requires the recognition and processing of that extension, then the
-document must include a <em>required</em> extension specification
-in one of its declared or referenced profiles.</p><p>The <code>ttp:extension</code> element is illustrated by the following example.</p><a id="profile-vocabulary-extension-example-1"></a><table class="example"><caption>Example Fragment – ttp:extension</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:profile use="http://www.w3.org/ns/ttml/profile/ttml2-transformation"&gt;
-  &lt;ttp:extensions xml:base="http://example.org/ttml/extension/"&gt;
-    <span class="strong">&lt;ttp:extension value="use"&gt;#prefilter-by-language&lt;/ttp:extension&gt;</span>
-  &lt;/ttp:extensions&gt;
-&lt;/ttp:profile&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the TTML transformation profile is used as
-the baseline profile. This baseline profile is then supersetted by
-specifying that support and use is required for a private extension
-defined in a third party namespace.</p><p>The effect of this example is to express authorial intentions that
-a recipient processor must support the TTML transformation profile and
-must also support and enable an extension defined by a third party.</p></div></div></div><div class="div2">
-<h3><a id="profile-attribute-vocabulary"></a>6.2 Profile Attribute Vocabulary</h3><p>The following attributes are defined in the TT Parameter Namespace.</p><ul><li><p><a href="#profile-attribute-contentProfiles"><b>6.2.1 ttp:contentProfiles</b></a></p></li><li><p><a href="#profile-attribute-contentProfileCombination"><b>6.2.2 ttp:contentProfileCombination</b></a></p></li><li><p><a href="#profile-attribute-inferProcessorProfileMethod"><b>6.2.3 ttp:inferProcessorProfileMethod</b></a></p></li><li><p><a href="#profile-attribute-inferProcessorProfileSource"><b>6.2.4 ttp:inferProcessorProfileSource</b></a></p></li><li><p><a href="#profile-attribute-permitFeatureNarrowing"><b>6.2.5 ttp:permitFeatureNarrowing</b></a></p></li><li><p><a href="#profile-attribute-permitFeatureWidening"><b>6.2.6 ttp:permitFeatureWidening</b></a></p></li><li><p><a href="#profile-attribute-profile"><b>6.2.7 ttp:profile</b></a></p></li><li><p><a href="#profile-attribute-processorProfiles"><b>6.2.8 ttp:processorProfiles</b></a></p></li><li><p><a href="#profile-attribute-processorProfileCombination"><b>6.2.9 ttp:processorProfileCombination</b></a></p></li><li><p><a href="#profile-attribute-validation"><b>6.2.10 ttp:validation</b></a></p></li><li><p><a href="#profile-attribute-validationAction"><b>6.2.11 ttp:validationAction</b></a></p></li><li><p><a href="#profile-attribute-version"><b>6.2.12 ttp:version</b></a></p></li></ul><p>Unless explicitly stated otherwise, linear white-space (LWSP) must
-appear between adjacent non-terminal components of a TT Parameter value
-unless some other delimiter is permitted and used.</p><div class="div3">
-<h4><a id="profile-attribute-contentProfiles"></a>6.2.1 ttp:contentProfiles</h4><p>The <code>ttp:contentProfiles</code> attribute may be used by a content author
-to express one or more <a href="#terms-content-profile">content profiles</a> of
-the Timed Text Markup Language (TTML) where the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a> claims conformance to any or all of the
-specified <a href="#terms-content-profile">content profiles</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax,
-where each <code>profile-designator</code> item adheres to the <code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, and, further, adheres to constraints defined on a profile designator in accordance with
-<a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>.</p><a id="profile-attribute-contentProfiles-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:contentProfiles</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:contentProfiles
-  : designators
-  | "all(" designators ")"
-  | "any(" designators ")"
-
-designators
-  : designator (lwsp designator)*
-
-designator
-  : xsd:anyURI
-
-lwsp
-  : ( ' ' | '\t' | '\n' | '\r' )+
-</pre></div>
-</td></tr></tbody></table><p>If the list of designators is enclosed in the function syntax <code>all(...)</code> or no function syntax is used,
-then conformance is claimed with all designated <a href="#terms-content-profile">content profiles</a>. If the list
-of designators is enclosed in the function syntax <code>any(...)</code>, then conformance is claimed with at least one
-of the designated <a href="#terms-content-profile">content profiles</a>.</p><p>A <code>ttp:contentProfiles</code>
-attribute is considered to be significant only when specified on the
-<code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-contentProfileCombination"></a>6.2.2 ttp:contentProfileCombination</h4><p>The <code>ttp:contentProfileCombination</code> attribute is used to specify the
-method for combining multiple <a href="#terms-content-profile">content profiles</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-contentProfileCombination-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:contentProfileCombination</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:contentProfileCombination
-  : "leastRestrictive"
-  | "mostRestrictive"
-  | "replace"
-</pre></div>
-</td></tr></tbody></table><p>Given two ordered profile specification values, <em>arg1</em> and <em>arg2</em>, and a content profile combination method,
-<a href="#content-profile-combination-table"><b>Table 6-1 – Content Profile Combination</b></a> specifies the result of combining the two specification values, where the order
-of arguments is determined in accordance with the lexical order of
-<a href="#terms-content-profile">content profiles</a> in a <a href="#terms-document-instance">document instance</a>.</p><a id="content-profile-combination-table"></a><table class="common"><caption>Table 6-1 – Content Profile Combination</caption><col width="16.67%" span="1"><col width="16.67%" span="1"><col width="22%" span="1"><col width="22%" span="1"><col width="22%" span="1"><tbody><tr><th><em>arg1</em></th><th><em>arg2</em></th><th><code>leastRestrictive</code></th><th><code>mostRestrictive</code></th><th><code>replace</code></th></tr><tr><td>optional</td><td>optional</td><td>optional</td><td>optional</td><td>optional</td></tr><tr><td>optional</td><td>required</td><td>optional</td><td>required</td><td>required</td></tr><tr><td>optional</td><td>prohibited</td><td>optional</td><td>prohibited</td><td>prohibited</td></tr><tr><td>required</td><td>optional</td><td>optional</td><td>required</td><td>optional</td></tr><tr><td>required</td><td>required</td><td>required</td><td>required</td><td>required</td></tr><tr><td>required</td><td>prohibited</td><td>required</td><td>prohibited</td><td>prohibited</td></tr><tr><td>prohibited</td><td>optional</td><td>optional</td><td>prohibited</td><td>optional</td></tr><tr><td>prohibited</td><td>required</td><td>required</td><td>prohibited</td><td>required</td></tr><tr><td>prohibited</td><td>prohibited</td><td>prohibited</td><td>prohibited</td><td>prohibited</td></tr></tbody></table><p>A <code>ttp:contentProfileCombination</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-inferProcessorProfileMethod"></a>6.2.3 ttp:inferProcessorProfileMethod</h4><p>The <code>ttp:inferProcessorProfileMethod</code> attribute is used to specify the
-method for mapping a content profile specification value to a corresponding processor
-profile specification value.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-inferProcessorProfileMethod-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:inferProcessorProfileMethod</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:inferProcessorProfileMethod
-  : "loose"
-  | "strict"
-</pre></div>
-</td></tr></tbody></table><p>If this parameter's value is <code>loose</code>, then, when inferring a processor profile specification from a content profile specification,
-a loose (liberal) mapping applies.</p><p>If this parameter's value is <code>strict</code>, then, when inferring a processor profile specification from a content profile specification,
-a strict (conservative) mapping applies.</p><p>If not specified, the value of this parameter must be considered
-to be <code>loose</code>.</p><p>Given an input content profile specification value, <em>input</em>, and an infer processor profile method,
-<a href="#infer-processor-profile-method-table"><b>Table 6-2 – Infer Processor Profile Method</b></a> specifies the result of mapping the input specification value.</p><a id="infer-processor-profile-method-table"></a><table class="common"><caption>Table 6-2 – Infer Processor Profile Method</caption><col width="33%" span="1"><col width="33%" span="1"><col width="33%" span="1"><tbody><tr><th><em>input</em></th><th><code>loose</code></th><th><code>strict</code></th></tr><tr><td>optional</td><td>optional</td><td>required</td></tr><tr><td>required</td><td>required</td><td>required</td></tr><tr><td>prohibited</td><td>optional</td><td>optional</td></tr></tbody></table><p>A <code>ttp:inferProcessorProfileMethod</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-inferProcessorProfileSource"></a>6.2.4 ttp:inferProcessorProfileSource</h4><p>The <code>ttp:inferProcessorProfileSource</code> attribute is used to specify the
-source for mapping a content profile specification value to a corresponding processor
-profile specification value.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-inferProcessorProfileSource-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:inferProcessorProfileSource</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:inferProcessorProfileSource
-  : "combined"
-  | "first"
-</pre></div>
-</td></tr></tbody></table><p>If this parameter's value is <code>combined</code>, then, when inferring a processor profile, the combined profile specification
-set of the <a href="#terms-effective-content-profile">effective content profile</a> is used as the source of inference.</p><p>If this parameter's value is <code>first</code>, then, when inferring a processor profile, the first constituent profile of
-the <a href="#terms-effective-content-profile">effective content profile</a>, where the processor profile inferred from that
-constituent profile is supported by the <a href="#terms-content-processor">content processor</a>, is used as the source of inference.</p><p>If not specified, the value of this parameter must be considered
-to be <code>combined</code>.</p><p>A <code>ttp:inferProcessorProfileSource</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-permitFeatureNarrowing"></a>6.2.5 ttp:permitFeatureNarrowing</h4><p>The <code>ttp:permitFeatureNarrowing</code> attribute is used to specify whether
-requirements related to a feature or extension may be satisfied by a (syntactically or semantically) narrower interpretation
-of the feature or extension.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-permitFeatureNarrowing-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:permitFeatureNarrowing</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:permitFeatureNarrowing
-  : <a href="http://www.w3.org/TR/xmlschema-2/#boolean">xsd:boolean</a>                             // see <a href="#xsd-2">[XML Schema Part 2]</a>, §3.2.2
-</pre></div>
-</td></tr></tbody></table><p>If this parameter's value is <code>true</code>, then, a requirement for support of a feature or extension may be satisfied
-if the definition of the feature or extension specifies an <code>extends</code> attribute, and the feature or extension referenced
-by that attribute is supported by a processor.</p><p>If this parameter's value is <code>false</code>, then, a requirement for support of a feature or extension can not be satisfied
-by a more narrowly defined feature or extension specified by an <code>extends</code> attribute.</p><p>If not specified, the value of this parameter must be considered
-to be <code>false</code>.</p><p>A <code>ttp:permitFeatureNarrowing</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-permitFeatureWidening"></a>6.2.6 ttp:permitFeatureWidening</h4><p>The <code>ttp:permitFeatureWidening</code> attribute is used to specify whether
-requirements related to a feature or extension may be satisfied by a (syntactically or semantically) wider interpretation
-of the feature or extension.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-permitFeatureWidening-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:permitFeatureWidening</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:permitFeatureWidening
-  : <a href="http://www.w3.org/TR/xmlschema-2/#boolean">xsd:boolean</a>                             // see <a href="#xsd-2">[XML Schema Part 2]</a>, §3.2.2
-</pre></div>
-</td></tr></tbody></table><p>If this parameter's value is <code>true</code>, then, a requirement for support of a feature or extension may be satisfied
-if the definition of the feature or extension specifies an <code>restricts</code> attribute, and the feature or extension referenced
-by that attribute is supported by a processor.</p><p>If this parameter's value is <code>false</code>, then, a requirement for support of a feature or extension can not be satisfied
-by a more widely defined feature or extension specified by an <code>restricts</code> attribute.</p><p>If not specified, the value of this parameter must be considered
-to be <code>false</code>.</p><p>A <code>ttp:permitFeatureWidening</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-profile"></a>6.2.7 ttp:profile</h4><p>The <code>ttp:profile</code> attribute is <span class="deprecated">deprecated</span>. If creating a TTML document instance for TTML2 (or later versions),
-then the <code>ttp:profile</code> attribute should not be used; instead, the content author should use the <code>ttp:processorProfiles</code>
-attribute, specified at <a href="#profile-attribute-processorProfiles"><b>6.2.8 ttp:processorProfiles</b></a>.</p><p>If used in a document, the <code>ttp:profile</code> attribute
-denotes a <a href="#terms-processor-profile">processor profile</a>
-of the Timed Text Markup Language (TTML) that applies when processing
-a <a href="#terms-document-instance">document instance</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For information on signaling content profile(s), see <a href="#profile-attribute-contentProfiles"><b>6.2.1 ttp:contentProfiles</b></a>.</p></div><p>If specified, the value of this attribute must adhere to the following syntax
-where the <code>designator</code> adheres to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, and, further, must specify a
-profile designator in accordance with
-<a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>.</p><a id="profile-attribute-profile-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:profile</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-<span class="deprecated">ttp:profile</span>
-  : designator
-
-designator
-  : xsd:anyURI
-</pre></div>
-</td></tr></tbody></table><p>A <code>ttp:profile</code>
-attribute is considered to be significant only when specified on the
-<code>tt</code> element.</p><p>If a <a href="#terms-top-level-profile">top-level</a> <a href="#terms-processor-profile">processor profile</a>
-is defined in a <a href="#terms-document-instance">document instance</a>, then the
-<a href="#profile-attribute-profile"><code>ttp:profile</code></a>
-attribute should not be specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-processorProfiles"></a>6.2.8 ttp:processorProfiles</h4><p>The <code>ttp:processorProfiles</code> attribute may be used by a content author
-to express one or more <a href="#terms-processor-profile">processor profiles</a> of
-the Timed Text Markup Language (TTML) where the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a> requires support for each and all
-specified <a href="#terms-processor-profile">processor profiles</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax,
-where each <code>profile-designator</code> item adheres to the <code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17, and, further, adheres to constraints defined on a profile designator in accordance with
-<a href="#vocabulary-profiling"><b>5.2 Profiling</b></a>.</p><a id="profile-attribute-processorProfiles-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:processorProfiles</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:processorProfiles
-  : designators
-  | "all(" designators ")"
-  | "any(" designators ")"
-
-designators
-  : designator (lwsp designator)*
-
-designator
-  : xsd:anyURI
-
-lwsp
-  : ( ' ' | '\t' | '\n' | '\r' )+
-</pre></div>
-</td></tr></tbody></table><p>If the list of designators is enclosed in the function syntax <code>all(...)</code> or no function syntax is used,
-then support is required for all designated <a href="#terms-processor-profile">processor profiles</a>. If the list
-of designators is enclosed in the function syntax <code>any(...)</code>, then support is required for at least one
-of the designated <a href="#terms-processor-profile">processor profiles</a>.</p><p>A <code>ttp:processorProfiles</code>
-attribute is considered to be significant only when specified on the
-<code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-processorProfileCombination"></a>6.2.9 ttp:processorProfileCombination</h4><p>The <code>ttp:processorProfileCombination</code> attribute is used to specify the
-method for combining multiple <a href="#terms-processor-profile">processor profiles</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-processorProfileCombination-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:processorProfileCombination</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:processorProfileCombination
-  : "leastRestrictive"
-  | "mostRestrictive"
-  | "replace"
-</pre></div>
-</td></tr></tbody></table><p>Given two ordered profile specification values, <em>arg1</em> and <em>arg2</em>, and a processor profile combination method,
-<a href="#processor-profile-combination-table"><b>Table 6-3 – Processor Profile Combination</b></a> specifies the result of combining the two specification values, where the order
-of arguments is determined in accordance with the lexical order of
-<a href="#terms-processor-profile">processor profiles</a> in a <a href="#terms-document-instance">document instance</a>.</p><a id="processor-profile-combination-table"></a><table class="common"><caption>Table 6-3 – Processor Profile Combination</caption><col width="16.67%" span="1"><col width="16.67%" span="1"><col width="22%" span="1"><col width="22%" span="1"><col width="22%" span="1"><tbody><tr><th><em>arg1</em></th><th><em>arg2</em></th><th><code>leastRestrictive</code></th><th><code>mostRestrictive</code></th><th><code>replace</code></th></tr><tr><td>optional</td><td>optional</td><td>optional</td><td>optional</td><td>optional</td></tr><tr><td>optional</td><td>required</td><td>optional</td><td>required</td><td>required</td></tr><tr><td>required</td><td>optional</td><td>optional</td><td>required</td><td>optional</td></tr><tr><td>required</td><td>required</td><td>required</td><td>required</td><td>required</td></tr></tbody></table><p>A <code>ttp:processorProfileCombination</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-validation"></a>6.2.10 ttp:validation</h4><p>The <code>ttp:validation</code> attribute is used to specify whether validation processing
-may or must be performed on a <a href="#terms-document-instance">document instance</a> by a
-<a href="#terms-validating-content-processor">validating content processor</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-validation-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:validation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:validation
-  : "required"
-  | "optional"
-  | "prohibited"
-</pre></div>
-</td></tr></tbody></table><p>If this parameter's value is <code>required</code>, then, a <a href="#terms-validating-content-processor">validating content processor</a>
-must perform validation processing on a TTML <a href="#terms-document-instance">document instance</a> prior to performing
-other types of processing, e.g., presentation or transformation processing.</p><p>If this parameter's value is <code>optional</code>, then, a <a href="#terms-validating-content-processor">validating content processor</a>
-may, but need not, perform validation processing on a TTML <a href="#terms-document-instance">document instance</a> prior to performing
-other types of processing, e.g., presentation or transformation processing.</p><p>If this parameter's value is <code>prohibited</code>, then, a <a href="#terms-validating-content-processor">validating content processor</a>
-must not perform validation processing on a TTML <a href="#terms-document-instance">document instance</a> prior to performing
-other types of processing, e.g., presentation or transformation processing, unless the end-user or application overrides this prohibition.</p><p>If validation processing is performed on a TTML <a href="#terms-document-instance">document instance</a> and validation fails, then the computed value of
-the <code>ttp:validationAction</code> parameter property is used to determine what action to take before performing further processing.</p><p>If not specified, the value of this parameter must be considered
-to be <code>optional</code>.</p><p>A <code>ttp:validation</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-validationAction"></a>6.2.11 ttp:validationAction</h4><p>The <code>ttp:validationAction</code> attribute is used to specify what action is to be taken
-by a <a href="#terms-validating-content-processor">validating content processor</a> when
-validation of a <a href="#terms-document-instance">document instance</a> fails.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-validationAction-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:validationAction</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:validationAction
-  : "abort"
-  | "warn"
-  | "ignore"
-</pre></div>
-</td></tr></tbody></table><p>If this parameter's value is <code>abort</code>, then, a <a href="#terms-validating-content-processor">validating content processor</a>
-must abort processing of a TTML <a href="#terms-document-instance">document instance</a> when validation processing fails.</p><p>If this parameter's value is <code>warn</code>, then, a <a href="#terms-validating-content-processor">validating content processor</a>
-should warn the end-user when validation processing fails, and, give the end-user the option to continue or abort processing.</p><p>If this parameter's value is <code>ignore</code>, then, a <a href="#terms-validating-content-processor">validating content processor</a>
-should not abort and should not warn the end-user when validation processing fails.</p><p>If not specified, the value of this parameter is determined as follows:
-if the computed value of the <a href="#profile-attribute-validation"><code>ttp:validation</code></a> parameter property is <code>required</code>,
-then the value must be considered to be <code>abort</code>;
-if it is <code>optional</code>,
-then the value must be considered to be <code>warn</code>;
-otherwise, if it is <code>prohibited</code>,
-then the value must be considered to be <code>ignore</code>.</p><p>A <code>ttp:validationAction</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="profile-attribute-version"></a>6.2.12 ttp:version</h4><p>The <code>ttp:version</code> attribute is used to specify which version of the
-<a href="#terms-timed-text-markup-language">Timed Text Markup Language</a>
-specification was used in authoring a TTML <a href="#terms-document-instance">document instance</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="profile-attribute-version-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:version</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:version
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+                                // <em>value</em> &gt; 0
-</pre></div>
-</td></tr></tbody></table><p>A <code>ttp:version</code> attribute must be specified on the root <code>tt</code>
-element of a <a href="#terms-document-instance">document instance</a> if it
-requires support for a <a href="#terms-feature">feature</a> not defined by <a href="#ttml1">[TTML1]</a>.</p><p>If not specified, the version must be considered to be
-equal to one (1). If specified, then the version must be greater than zero (0). The version associated
-with this version of the <a href="#terms-timed-text-markup-language">Timed Text Markup Language</a>
-specification is two (2).</p><p>A <code>ttp:version</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <a href="#terms-content-processor">content processor</a> typically uses the
-declared version to perform a preliminary assessment of whether it is capable of
-processing a given <a href="#terms-document-instance">document instance</a>.
-However, it does not assume that the <a href="#terms-document-instance">document instance</a>
-actually uses or requires support for a <a href="#terms-feature">feature</a>
-not defined in prior versions. In other
-words, a <a href="#terms-content-processor">content processor</a> does not reject
-a <a href="#terms-document-instance">document instance</a> simply because it declares
-it was authored against a version of the <a href="#terms-timed-text-markup-language">Timed Text Markup Language</a>
-specification that was not yet published at the time the processor was implemented.</p><p>The computed value of the parameter property expresssed by the <code>ttp:version</code> attribute is used by the
-<a href="#semantics-procedure-construct-default-processor-profile"><span class="strong">construct default processor profile</span></a>
-procedure to determine the <a href="#terms-default-processor-profile">default processor profile</a>.</p></div></div></div></div><div class="div1">
-<h2><a id="parameter"></a>7 Parameter</h2><p>This section specifies the <em>parameter</em> matter of the
-core vocabulary catalog, where
-parameters are to be understood as information that is either (1)
-essential or (2) of significant importance for the purpose of
-interpreting the semantics of other types of information expressed by
-core vocabulary items or for establishing a <a href="#terms-document-processing-context">document processing context</a> by means
-of which TTML Content can be related to an external environment.</p><div class="div2">
-<h3><a id="parameter-element-vocabulary"></a>7.1 Parameter Element Vocabulary</h3><p>No parameter element vocabulary is defined in this specification.</p></div><div class="div2">
-<h3><a id="parameter-attribute-vocabulary"></a>7.2 Parameter Attribute Vocabulary</h3><p>The following attributes are defined in the TT Parameter Namespace.</p><ul><li><p><a href="#parameter-attribute-cellResolution"><b>7.2.1 ttp:cellResolution</b></a></p></li><li><p><a href="#parameter-attribute-clockMode"><b>7.2.2 ttp:clockMode</b></a></p></li><li><p><a href="#parameter-attribute-dropMode"><b>7.2.3 ttp:dropMode</b></a></p></li><li><p><a href="#parameter-attribute-frameRate"><b>7.2.4 ttp:frameRate</b></a></p></li><li><p><a href="#parameter-attribute-frameRateMultiplier"><b>7.2.5 ttp:frameRateMultiplier</b></a></p></li><li><p><a href="#parameter-attribute-markerMode"><b>7.2.6 ttp:markerMode</b></a></p></li><li><p><a href="#parameter-attribute-mediaDuration"><b>7.2.7 ttp:mediaDuration</b></a></p></li><li><p><a href="#parameter-attribute-mediaOffset"><b>7.2.8 ttp:mediaOffset</b></a></p></li><li><p><a href="#parameter-attribute-pixelAspectRatio"><b>7.2.9 ttp:pixelAspectRatio</b></a></p></li><li><p><a href="#parameter-attribute-storageAspectRatio"><b>7.2.10 ttp:storageAspectRatio</b></a></p></li><li><p><a href="#parameter-attribute-subFrameRate"><b>7.2.11 ttp:subFrameRate</b></a></p></li><li><p><a href="#parameter-attribute-tickRate"><b>7.2.12 ttp:tickRate</b></a></p></li><li><p><a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a></p></li></ul><p>Unless explicitly stated otherwise, linear white-space (LWSP) must
-appear between adjacent non-terminal components of a TT Parameter value
-unless some other delimiter is permitted and used.</p><div class="div3">
-<h4><a id="parameter-attribute-cellResolution"></a>7.2.1 ttp:cellResolution</h4><p>The <code>ttp:cellResolution</code> attribute may be used by an author
-to express the number of horizontal and vertical cells into which the <a href="#terms-root-container-region">root container region</a>
-area is divided for the purpose of expressing presentation semantics in terms of
-a uniform grid.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-cellResolution-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:cellResolution</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:cellResolution
-  : columns rows                            // <em>columns</em> != 0; <em>rows</em> != 0
-
-columns | rows
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table><p>If not specified, the number of columns and rows must be considered
-to be 32 and 15, respectively. If specified, then columns or rows must not be zero (0).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The choice of values 32 and 15 are based on this being the
-maximum number of columns and rows defined by <a href="#cea608e">[CEA-608-E]</a>.</p></div><p>A <code>ttp:cellResolution</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of a uniform grid is employed only for the purpose of
-measuring lengths and expressing coordinates. In particular, it is not
-assumed that the presentation of text or the alignment of individual
-glyph areas is
-coordinated with this grid. Such alignment is possible, but
-requires the use of a monospaced font and a font size whose EM square exactly
-matches the cell size.</p></div><p>Except where indicated otherwise, when a <a href="#style-value-length">&lt;length&gt;</a> expressed in
-cells denotes a dimension parallel to the inline or block progression dimension,
-the cell's dimension in the inline or block progression dimension applies, respectively.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, if padding (on all four edges) is specified as 0.1c, the cell resolution
-is 20 by 10, and the extent of the <a href="#terms-root-container-region">root container region</a> is 640 by 480, then, assuming top to bottom,
-left to right writing mode, the start and end padding will be (640 / 20) * 0.1 pixels and the
-before and after padding will be (480 / 10) * 0.1 pixels.</p></div></div><div class="div3">
-<h4><a id="parameter-attribute-clockMode"></a>7.2.2 ttp:clockMode</h4><p>The <code>ttp:clockMode</code> attribute is used to specify the
-interpretation of time expressions as real-time time coordinates when
-operating with time base of <code>clock</code> as defined by <a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#timing-time-value-expressions"><b>12.3 Time Value Expressions</b></a> for the
-specification of time expression syntax and semantics.</p></div><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-clockMode-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:clockMode</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:clockMode
-  : "local"
-  | "gps"
-  | "utc"
-</pre></div>
-</td></tr></tbody></table><p>If the time base, defined by <a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a>, is designated as
-<code>clock</code>, then this parameter applies as follows: if the
-parameter's value is <code>local</code>, then time expressions are
-interpreted as local wall-clock time coordinates;
-if <code>utc</code>, then time expressions are
-interpreted as UTC time coordinates
-<a href="#utc">[UTC]</a>;
-if <code>gps</code>, then time expressions are
-interpreted as GPS time coordinates
-<a href="#gps">[GPS]</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The primary difference between GPS time and UTC time is that GPS
-time is not adjusted for leap seconds, while UTC time is adjusted as
-follows: UTC = TAI (<em>Temp Atomique International</em>) + <em>leap seconds
-accumulated since 1972</em>. TAI is maintained by the <em>Bureau
-International des Poids et Mesures</em> (BIPM) in Sevres, France.
-The GPS system time is steered to a Master Clock (MC) at the US Naval
-Observatory which is kept within a close but unspecified
-tolerance of TAI.</p></div><p>If not specified, the value of this parameter must be considered
-to be <code>utc</code>.</p><p>A <code>ttp:clockMode</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="parameter-attribute-dropMode"></a>7.2.3 ttp:dropMode</h4><p>The <code>ttp:dropMode</code> attribute is used to specify
-constraints on the interpretation and use of frame counts
-that correspond with <a href="#smpte12m">[SMPTE 12M]</a> time coordinates when operating
-with time base of <code>smpte</code> as defined by
-<a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-dropMode-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:dropMode</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:dropMode
-  : "dropNTSC"
-  | "dropPAL"
-  | "nonDrop"
-</pre></div>
-</td></tr></tbody></table><p>If the time base, defined by <a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a>, is designated as
-<code>smpte</code>, then this parameter applies as follows: if the
-parameter's value is <code>nonDrop</code>, then, within any given
-second of a time expression, frames count from 0 to
-<em>N−1</em>, where <em>N</em> is the value specified by
-the <code>ttp:frameRate</code> parameter, but while ignoring any value
-specified by the <code>ttp:frameRateMultiplier</code> parameter.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When operating in <code>nonDrop</code>
-mode, a second of a time expression may or may not be equal to a
-second of real time during normal (1x speed) forward playback. If the
-<code>ttp:frameRateMultiplier</code> parameter is specified and is not
-equal to 1:1, then a second of a time expression will either be
-shorter or longer than a second of elapsed play in real
-time.</p></div><p>If this parameter's value is <code>dropNTSC</code>, then, within any
-given second of a time expression except the second <code>00</code>,
-frames count from 0 to <em>N−1</em>, where <em>N</em> is
-the value specified by the <code>ttp:frameRate</code> parameter, but
-while ignoring any value specified by the
-<code>ttp:frameRateMultiplier</code> parameter. If the second of a time
-expression is <code>00</code> and the minute of the time expression is
-not <code>00</code>, <code>10</code>, <code>20</code>, <code>30</code>,
-<code>40</code>, or <code>50</code>, then frame codes <code>00</code>
-and <code>01</code> are dropped during that second; otherwise, these
-frame codes are not dropped.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, when operating in <code>dropNTSC</code>
-mode with <code>ttp:frameRate</code> of <code>30</code>, a discontinuity
-in frame count occurs between consecutive frames as shown in the
-following sequence of time expressions: <code>01:08:59:28</code>,
-<code>01:08:59:29</code>, <code>01:09:00:02</code>,
-<code>01:09:00:03</code>.</p></div><p>If this parameter's value is <code>dropPAL</code>, then, within any
-given second of a time expression except the second <code>00</code>,
-frames count from 0 to <em>N−1</em>, where <em>N</em> is
-the value specified by the <code>ttp:frameRate</code> parameter, but
-while ignoring any value specified by the
-<code>ttp:frameRateMultiplier</code> parameter. If the second of a time
-expression is <code>00</code> and the minute of the time expression is
-even but not <code>00</code>, <code>20</code>, or <code>40</code>,
-then frame codes <code>00</code> through <code>03</code> are dropped
-during that second; otherwise, these frame codes are not dropped.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, when operating in <code>dropPAL</code>
-mode with <code>ttp:frameRate</code> of <code>30</code>, a discontinuity
-in frame count occurs between consecutive frames as shown in the
-following sequence of time expressions: <code>01:09:59:28</code>,
-<code>01:09:59:29</code>, <code>01:10:00:04</code>,
-<code>01:10:00:05</code>.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The <code>dropPAL</code> mode is also known as the
-<em>M/PAL</em> or <em>PAL (M)</em> drop-frame
-code, which uses PAL modulation with the NTSC frame rate of ~29.97
-frames/second. The M/PAL system is used primarily in Brazil.</p></div><p>If not specified, then <code>nonDrop</code> must be assumed to apply.</p><p>A <code>ttp:dropMode</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="parameter-attribute-frameRate"></a>7.2.4 ttp:frameRate</h4><p>The <code>ttp:frameRate</code> attribute is used to specify the frame rate of a related
-media object or the intrinsic frame rate of a <a href="#terms-document-instance">document instance</a> in case it is intended
-to function as an independent media object.</p><div class="issue"><p class="prefix"><a id="issue-333"></a><b>Issue (issue-333):</b></p><p class="prefix"><b>Defaulting Frame Rate Multiplier, Sub Frame Rate</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/333">http://www.w3.org/AudioVideo/TT/tracker/issues/333</a></p><p>If frame rate is defaulted to processing environment, then frame rate multiplier and sub frame rate should be as well.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-frameRate-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:frameRate</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:frameRate
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+                                // <em>value</em> &gt; 0
-</pre></div>
-</td></tr></tbody></table><p>The frame rate that applies to a <a href="#terms-document-instance">document instance</a> is used to
-interpret time expressions that are expressed in <em>frames</em>
-as defined by <a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a>.</p><p>If the <code>media</code> time base applies and the effective frame rate is
-integral, then a frame is interpreted as a division of a second of media
-time, such that if the frame rate is specified as <em>F</em>, then
-a second of media time is divided into <em>F</em> intervals of
-equal duration, where each interval is labeled as frame <em>f</em>,
-with <em>f</em> ∈ [0…<em>F−1</em>].</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#time-expression-semantics-media"><b>H.2 Media Time Base</b></a> for further details
-on the interpretation of time expressions for the <code>media</code> time base.</p></div><p>If not specified, the frame rate must be considered to be equal to some
-application defined frame rate, or if no application defined frame rate applies,
-then thirty (30) frames per second. If specified, then the frame rate must
-be greater than zero (0).</p><p>A <code>ttp:frameRate</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="parameter-attribute-frameRateMultiplier"></a>7.2.5 ttp:frameRateMultiplier</h4><p>The <code>ttp:frameRateMultiplier</code> attribute is used to
-specify a multiplier to be applied to the frame rate specified by a
-<code>ttp:frameRate</code> attribute in order to compute the effective
-frame rate.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-frameRateMultiplier-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:frameRateMultiplier</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:frameRateMultiplier
-  : numerator denominator                   // <em>numerator</em> != 0; <em>denominator</em> != 0
-
-numerator | denominator
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table><p>A frame rate multiplier is used when the desired frame rate cannot
-be expressed as an integral number of frames per second.</p><p>If not specified, the frame rate multiplier must be considered to be equal to one (1:1).
-Both numerator and denominator must be non-zero.</p><p>A <code>ttp:frameRateMultiplier</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The frame rate multiplier used for synchronizing with NTSC <a href="#smpte170m">[SMPTE 170M]</a>
-formatted video objects at 30 frames per second is nominally
-1000:1001. The nominal frame rate of NTSC video is defined as the chrominance
-sub-carrier frequency of 3,579,545.45…Hz (= 5.0MHz × 63/88) times the ratio 2/455 divided by
-the number of horizontal lines per frame of 525, which yields a frame
-rate of 29.970029970029… (= 30 × 1000/1001) frames per
-second. Other frame rate multipliers apply to different regions of
-usage and video format standards.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>Except in the case of PAL/M, the frame rate multiplier used for synchronizing with PAL
-formatted video objects at 25 frames per second is nominally 1:1.</p></div></div><div class="div3">
-<h4><a id="parameter-attribute-markerMode"></a>7.2.6 ttp:markerMode</h4><p>The <code>ttp:markerMode</code> attribute is used to specify
-constraints on the interpretation and use of time expressions
-that correspond with <a href="#smpte12m">[SMPTE 12M]</a> time coordinates when operating
-with time base of <code>smpte</code> as defined by
-<a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-markerMode-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:markerMode</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:markerMode
-  : "continuous"
-  | "discontinuous"
-</pre></div>
-</td></tr></tbody></table><p>If the time base, defined by <a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a>, is designated as
-<code>smpte</code>, then this parameter applies as follows: if the
-parameter's value is <code>continuous</code>, then <a href="#smpte12m">[SMPTE 12M]</a> time coordinates
-may be assumed to be linear and either monotonically increasing or
-decreasing; however, if <code>discontinuous</code>, then any assumption
-must not be made regarding linearity or monotonicity of time coordinates.</p><p>If not specified, the value of this parameter must be considered
-to be <code>discontinuous</code>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The default value for this parameter was originally specified
-(in <a href="http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/">TTML 1.0 First Edition</a>)
-as <code>continuous</code>; however, further evaluation of the state of the industry indicated this
-choice was incorrect, and that the most common default is <code>discontinuous</code>.</p></div><p>A <code>ttp:markerMode</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><p>If a value of <code>continuous</code> applies, then time
-expressions may be converted to real time
-coordinates by taking into account the computed frame rate
-and drop mode as expressed by the <code>ttp:dropMode</code> parameter.
-In this case, the <a href="#terms-content-processor">content processor</a> must create and maintain a
-<a href="#terms-synthetic-smpte-document-syncbase">synthetic smpte document syncbase</a> within which these time
-expressions are interpreted as further described in
-<a href="#semantics-timing"><b>12.4 Timing Semantics</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When operating with <code>smpte</code> time base and
-<code>continuous</code> marker mode, there is an implied time coordinate
-space, the <a href="#terms-synthetic-smpte-document-syncbase">synthetic smpte document syncbase</a>,
-defined by the monotonically increasing (or decreasing) 
-<a href="#smpte12m">[SMPTE 12M]</a> time coordinates, while taking into account
-the computed frame rate and drop mode. All time expressions are interpreted
-in relationship to this time coordinate space based upon
-<a href="#terms-smpte-time-code">smpte time code</a> synchronization events (markers),
-where the <a href="#terms-document-processing-context">document processing context</a> emits these events with implied constraints
-regarding time coordinate monoticity and resynchronization in
-the presence of dropped frames.</p><p>Use of <code>continuous</code> marker mode with the <code>smpte</code>
-time base is different from using the <code>media</code> time base
-because (1) the semantics of the <code>ttp:dropMode</code> parameter
-apply to the former, but not the latter, and (2) <a href="#smpte12m">[SMPTE 12M]</a>
-time coordinates may be applied monotonically to media which has been
-subjected to dilation in time, constriction in time, or reversal in
-time.</p></div><p>If a value of <code>discontinuous</code> applies, then time
-expressions must not be converted to real time
-coordinates, arithmetical operators (addition, multiplication) are not
-defined on time expressions, and, consequently, any (well-formed)
-expression of a duration must be considered to be invalid.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When operating with <code>smpte</code> time base and
-<code>discontinuous</code> marker mode, there is no effective time coordinate
-space; rather, all time expressions are interpreted as labeled
-synchronization events (markers), where the <a href="#terms-document-processing-context">document processing context</a>
-emits these events, which, when they correspond with time
-expressions that denote the same label, cause a temporal interval to
-begin or end accordingly.</p><p>An additional side-effect of operating in <code>discontinuous</code>
-mode is that time expressions of children have no necessary
-relationship with time expressions of their temporal container; that
-is, temporal containers and children of these containers are
-temporally activated and inactivated independently based on the
-occurrence of a labeled synchronization (marker) event.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The notion of marker discontinuity as captured by this parameter
-is logically independent from the method used to count frames as
-expressed by the <code>ttp:dropMode</code> parameter. In particular,
-even if the <code>ttp:dropMode</code> parameter is specified as
-<code>dropNTSC</code> or <code>dropPAL</code>, the marker mode may be
-specified as <code>continuous</code>, even in the presence of frame count
-discontinuities induced by the frame counting method, unless there
-were some other non-linearity or discontinuity in marker labeling, for
-example, two consecutive frames labeled as <code>10:00:00:00</code>
-and <code>10:00:01:00</code>.
-</p></div></div><div class="div3">
-<h4><a id="parameter-attribute-mediaDuration"></a>7.2.7 ttp:mediaDuration</h4><p>The <code>ttp:mediaDuration</code> attribute is used to specify the
-temporal extent (simple duration) of a <a href="#terms-related-media-object">related media object</a>.</p><p>If the temporal extent (simple duration) of the <a href="#terms-related-media-object">related media object</a> is known at authoring time, then this
-attribute should be specified; otherwise, if no <a href="#terms-related-media-object">related media object</a> applies or its
-temporal extent is unknown, then this attribute should not be specified.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-mediaDuration-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:mediaDuration</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:mediaDuration
-  : <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>                        // restricted to <em>offset-time</em> form
-  | "indefinite"
-</pre></div>
-</td></tr></tbody></table><p>If specified, the value of this parameter must either (1) adhere to the <em>offset-time</em> form of
-a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> or (2) take the value <code>indefinite</code>.</p><p>If the value <code>indefinite</code> is specified, then there is no <a href="#terms-related-media-object">related media object</a>,
-the temporal extent (simple duration) of the
-<a href="#terms-related-media-object">related media object</a> is not known at the time this attribute is
-encoded, or the <a href="#terms-related-media-object">related media object</a> has no temporal end point.</p><p>If not specified, the value of this parameter must be considered
-to be <code>indefinite</code>.</p><p>A <code>ttp:mediaDuration</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#timing-time-value-expressions"><b>12.3 Time Value Expressions</b></a> for the
-specification of time expression syntax and semantics.</p></div></div><div class="div3">
-<h4><a id="parameter-attribute-mediaOffset"></a>7.2.8 ttp:mediaOffset</h4><p>The <code>ttp:mediaOffset</code> attribute is used to specify the
-temporal offset between the begin time of the <a href="#terms-root-temporal-extent">root temporal extent</a>
-and the begin time of a <a href="#terms-related-media-object">related media object</a> when operating in a
-<a href="#time-expression-semantics-media">Media Time Base</a>
-or a <a href="#time-expression-semantics-smpte">SMPTE Time Base</a>. It does not apply and
-must not be specified when operating in a <a href="#time-expression-semantics-clock">Clock Time Base</a>.</p><div class="issue"><p class="prefix"><a id="issue-270"></a><b>Issue (issue-270):</b></p><p class="prefix"><b>Media Time Offset</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/270">http://www.w3.org/AudioVideo/TT/tracker/issues/270</a></p><p>Tie up loose ends with respect to definition of media time offset, particulary regarding the definition of the origin and beginning of
-the document temporal extent.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p></p><div class="issue"><p class="prefix"><a id="issue-335"></a><b>Issue (issue-335):</b></p><p class="prefix"><b>Media Time Offset</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/335">http://www.w3.org/AudioVideo/TT/tracker/issues/335</a></p><p>Tie up loose ends with respect to definition of media time offset, particulary regarding the definition of the origin and beginning of
-the document temporal extent.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-mediaOffset-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:mediaOffset</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:mediaOffset
-  : sign? <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>                  // restricted to <em>offset-time</em> form
-
-sign
-  : "+" | "-"
-</pre></div>
-</td></tr></tbody></table><p>If specified, the value of this parameter must adhere to the <em>offset-time</em> form of
-a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> optionally expressed with a sign.
-If not specified, the value of this parameter must be considered
-to be <code>0s</code>.</p><p>If no sign is specified or it is specified as <code>+</code>, then the begin time of the
-<a href="#terms-root-temporal-extent">root temporal extent</a> follows the begin time of the
-<a href="#terms-related-media-object">related media object</a>; otherwise (sign is present and
-specified as <code>-</code>), the begin time of the
-<a href="#terms-root-temporal-extent">root temporal extent</a> precedes the begin time of the
-<a href="#terms-related-media-object">related media object</a>.</p><p>A <code>ttp:mediaOffset</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#timing-time-value-expressions"><b>12.3 Time Value Expressions</b></a> for the
-specification of time expression syntax and semantics.</p></div></div><div class="div3">
-<h4><a id="parameter-attribute-pixelAspectRatio"></a>7.2.9 ttp:pixelAspectRatio</h4><p>The <code>ttp:pixelAspectRatio</code> attribute may be used to express the <a href="#terms-pixel-aspect-ratio">pixel aspect ratio</a> associated with the
-<a href="#terms-authoring-viewport">authoring viewport</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-pixelAspectRatio-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:pixelAspectRatio</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:pixelAspectRatio
-  : numerator demoninator                   // <em>numerator</em> != 0; <em>demoninator</em> != 0
-
-numerator | demoninator
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table><p>If not specified, then square pixels (i.e., aspect ratio 1:1) must be assumed to apply.
-If specified, then both numerator and demoninator must be non-zero.</p><p>A <code>ttp:pixelAspectRatio</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="parameter-attribute-storageAspectRatio"></a>7.2.10 ttp:storageAspectRatio</h4><p>The <code>ttp:storageAspectRatio</code> attribute may be used to express the <a href="#terms-storage-aspect-ratio">storage aspect ratio</a> associated with the
-<a href="#terms-authoring-viewport">authoring viewport</a>.</p><div class="issue"><p class="prefix"><a id="issue-201"></a><b>Issue (issue-201):</b></p><p class="prefix"><b>Maintaining Display Aspect Ratio</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/201">http://www.w3.org/AudioVideo/TT/tracker/issues/201</a></p><p>Tie up loose ends with respect to support for retaining display aspect ratio. See also new values of <a href="#style-attribute-extent"><code>tts:extent</code></a>:
-<code>contain</code> and <code>cover</code>.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-storageAspectRatio-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:storageAspectRatio</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:storageAspectRatio
-  : numerator demoninator                   // <em>numerator</em> != 0; <em>demoninator</em> != 0
-
-numerator | demoninator
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table><p>If specified, then both numerator and demoninator must be non-zero.
-If not specified, then the storage aspect ratio of the <a href="#terms-authoring-viewport">authoring viewport</a> is undefined.</p><p>A <code>ttp:storageAspectRatio</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="parameter-attribute-subFrameRate"></a>7.2.11 ttp:subFrameRate</h4><p>The <code>ttp:subFrameRate</code> attribute is used to specify the sub-frame rate of a related
-media object or the intrinsic sub-frame rate of a <a href="#terms-document-instance">document instance</a> in case it is intended
-to function as an independent media object.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-subFrameRate-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:subFrameRate</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:subFrameRate
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+                                // <em>value</em> &gt; 0
-</pre></div>
-</td></tr></tbody></table><p>The sub-frame rate that applies to a <a href="#terms-document-instance">document instance</a> is used to
-interpret time expressions that are expressed in <em>sub-frames</em>
-as defined by <a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a>.</p><p>If the <code>media</code> time base applies and the effective frame rate is
-integral, a sub-frame is interpreted as a division of a frame of media
-time, such that if the sub-frame rate is specified as <em>S</em>, then
-a frame of media time is divided into <em>S</em> intervals of
-equal duration, where each interval is labeled as sub-frame <em>s</em>,
-with <em>s</em> ∈ [0…<em>S−1</em>].</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#time-expression-semantics-media"><b>H.2 Media Time Base</b></a> for further details
-on the interpretation of time expressions for the <code>media</code> time base.</p></div><p>If not specified, the sub-frame rate must be considered to be
-equal to one (1). If specified, then the sub-frame rate must be greater than zero (0).</p><p>A <code>ttp:subFrameRate</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The sub-frame is sometimes referred to as a <em>field</em> in
-the context of synchronization with an interlaced video media object.</p></div></div><div class="div3">
-<h4><a id="parameter-attribute-tickRate"></a>7.2.12 ttp:tickRate</h4><p>The <code>ttp:tickRate</code> attribute is used to specify the tick rate of a related
-media object or the intrinsic tick rate of content of a <a href="#terms-document-instance">document instance</a> in case it is intended
-to function as an independent media object.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-tickRate-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:tickRate</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:tickRate
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+                                // <em>value</em> &gt; 0
-</pre></div>
-</td></tr></tbody></table><p>The tick rate that applies to a <a href="#terms-document-instance">document instance</a> is used to
-interpret time expressions that are expressed in <em>ticks</em> by
-using the <code>t</code> metric as defined by <a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a>.</p><p>If the <code>media</code> time base applies,
-a tick is interpreted as an integral division of a second of media
-time, such that if the tick rate is specified as <em>T</em>, then
-a second of media time is divided into <em>T</em> intervals of
-equal duration, where each interval is labeled as tick <em>t</em>,
-with <em>t</em> ∈ [0…<em>T−1</em>].</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#time-expression-semantics-media"><b>H.2 Media Time Base</b></a> for further details
-on the interpretation of time expressions for the <code>media</code> time base.</p></div><p>If not specified, then if a frame rate is specified, the tick rate
-must be considered to be the effective frame rate multiplied by the
-sub-frame rate (i.e., ticks are interpreted as sub-frames); or, if no
-frame rate is specified, the tick rate must be considered to be one (1)
-tick per second of media time. If specified, then the tick rate
-must not be zero (0).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>There is no predefined relationship between ticks and frames or
-sub-frames. Ticks are an arbitrary division of seconds that permit
-use of fixed point arithmetic rather than fractional (and potentially
-inexact) expressions of seconds.</p></div><p>A <code>ttp:tickRate</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p></div><div class="div3">
-<h4><a id="parameter-attribute-timeBase"></a>7.2.13 ttp:timeBase</h4><p>The <code>ttp:timeBase</code> attribute is used to specify the
-temporal coordinate system by means of which time expressions are
-interpreted in a <a href="#terms-document-instance">document instance</a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><a id="parameter-attribute-timeBase-syntax"></a><table class="syntax"><caption>Syntax Representation – ttp:timeBase</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:timeBase
-  : "media"
-  | "smpte"
-  | "clock"
-</pre></div>
-</td></tr></tbody></table><p>If the time base is designated as <code>media</code>, then a time
-expression denotes a coordinate in some media object's time line,
-where the media object may be an external media object with which the
-content of a <a href="#terms-document-instance">document instance</a> is to be synchronized, or it may
-be the content of a <a href="#terms-document-instance">document instance</a> itself in a case where
-the timed text content is intended to establish an independent time
-line.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When using a media time base, if that time base is paused or
-scaled positively or negatively, i.e., the media play rate is
-not unity, then it is expected that the
-presentation of associated Timed Text content will be similarly
-paused, accelerated, or decelerated, respectively. The means for
-controlling an external
-media time base is outside the scope of this specification.</p></div><p>If the time base is designated as <code>smpte</code>,
-then a time expression denotes a <a href="#smpte12m">[SMPTE 12M]</a> time
-coordinate with which the content of a <a href="#terms-document-instance">document instance</a> is to
-be synchronized.  In this case, the value of the <code>ttp:markerMode</code> 
-and <code>ttp:dropMode</code> parameters apply, as defined by <a href="#parameter-attribute-markerMode"><b>7.2.6 ttp:markerMode</b></a> and <a href="#parameter-attribute-dropMode"><b>7.2.3 ttp:dropMode</b></a>, respectively.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When the time base is designated as <code>smpte</code>,
-every time expression denotes a media marker value akin to that
-defined by <a href="#smil3">[SMIL 3.0]</a>, § 5.4.3, except instead
-of using an opaque marker name, a structured <a href="#smpte12m">[SMPTE 12M]</a>
-time coordinate serves as the marker name.</p></div><p>If the time base is designated as <code>clock</code>, then the time
-expression denotes a coordinate in some real-world time line as
-established by some real-time clock, such as the local wall-clock time
-or UTC (Coordinated Universal Time) or GPS (Global Positioning System)
-time lines.</p><p>If not specified, the default time base must be considered to be
-<code>media</code>.</p><p>A <code>ttp:timeBase</code> attribute is considered to be significant only
-when specified on the <code>tt</code> element.</p><p>When operating with either <code>media</code> or <code>smpte</code>
-time bases, a diachronic presentation of a <a href="#terms-document-instance">document instance</a> may
-be subject to transformations of the controlling time line, such as
-temporal reversal, dilation (expansion), or constriction
-(compression); however, when operating with the <code>clock</code>
-time base, no transformations are permitted, and diachronic
-presentation proceeds on a linear, monotonically increasing time line
-based on the passage of real time.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Due to there being only one time base parameter that applies to a
-given <a href="#terms-document-instance">document instance</a>, the interpretation of time expressions
-is uniform throughout the <a href="#terms-document-instance">document instance</a>.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#time-expression-semantics"><b>H Time Expression Semantics</b></a> for further details
-on the interpretation of time expressions according to the designated time base.</p></div></div></div></div><div class="div1">
-<h2><a id="content"></a>8 Content</h2><p>This section specifies the <em>content</em> matter of the core
-vocabulary catalog.</p><div class="div2">
-<h3><a id="content-element-vocabulary"></a>8.1 Content Element Vocabulary</h3><p>The following elements specify the structure and principal content aspects of a
-<a href="#terms-document-instance">document instance</a>:</p><ul><li><p><a href="#document-structure-vocabulary-tt"><b>8.1.1 tt</b></a></p></li><li><p><a href="#document-structure-vocabulary-head"><b>8.1.2 head</b></a></p></li><li><p><a href="#document-structure-vocabulary-body"><b>8.1.3 body</b></a></p></li><li><p><a href="#content-vocabulary-div"><b>8.1.4 div</b></a></p></li><li><p><a href="#content-vocabulary-p"><b>8.1.5 p</b></a></p></li><li><p><a href="#content-vocabulary-span"><b>8.1.6 span</b></a></p></li><li><p><a href="#content-vocabulary-br"><b>8.1.7 br</b></a></p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>The sub-sections of this section are ordered logically (from highest to lowest level construct).</p></div><div class="div3">
-<h4><a id="document-structure-vocabulary-tt"></a>8.1.1 tt</h4><p>The <code>tt</code> element serves as the root document element of a <a href="#terms-document-instance">document instance</a>.</p><p>The <code>tt</code> element accepts as its children zero or one <code>head</code> element followed by
-zero or one <code>body</code> element.</p><a id="elt-syntax-tt"></a><table class="syntax"><caption>XML Representation – Element Information Item: tt</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#style-attribute-extent">tts:extent</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#style-attribute-position">tts:position</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang"><span class="reqattr">xml:lang</span></a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>) : default
-  {<em>any attribute in TT Parameter namespace</em>}
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#document-structure-vocabulary-head">head</a>?, <a href="#document-structure-vocabulary-body">body</a>?
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>The <a href="#terms-root-temporal-extent">root temporal extent</a>, i.e., the time interval over which a <a href="#terms-document-instance">document instance</a> is active, has an implicit duration that is equal to the
-implicit duration of the <code>body</code> element of the document, if the <code>body</code> element is present, or zero, if the <code>body</code> element is absent.</p><p>If the <a href="#style-attribute-extent"><code>tts:extent</code></a> attribute is specified on the <code>tt</code>
-element, then it must adhere to <a href="#style-attribute-extent"><b>10.2.11 tts:extent</b></a>, in which case it
-specifies the spatial extent of the <a href="#terms-root-container-region">root container region</a> in
-which <a href="#terms-content-region">content regions</a> are located and presented. If no <code>tts:extent</code>
-attribute is specified, then the spatial extent of the <a href="#terms-root-container-region">root container region</a> is
-considered to be determined by the <a href="#terms-document-processing-context">document processing context</a>.
-The origin of the <a href="#terms-root-container-region">root container region</a> is determined by the <a href="#terms-document-processing-context">document processing context</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In the absence of other requirements, and if a <a href="#terms-related-media-object">related media object</a> exists, then it is recommended
-that the <a href="#terms-document-processing-context">document processing context</a> determine that:</p><ul><li><p>if no <code>tts:extent</code> is specified on the root <code>tt</code> element, the extent of the <a href="#terms-root-container-region">root container region</a> be
-established as equal to the extent of the <a href="#terms-related-media-object-region">related media object region</a>; and</p></li><li><p>the origin of the <a href="#terms-root-container-region">root container region</a> be established so that this region is centered in the
-<a href="#terms-related-media-object-region">related media object region</a>.</p></li></ul></div><div class="note"><p class="prefix"><b>Note:</b></p><p>If an author desires to signal the (storage or image) aspect ratio of the <a href="#terms-root-container-region">root container region</a>
-without specifying its resolution, then this may be accomplished by using metadata specified
-in an external namespace, such as <code>m708:aspectRatio</code> as defined in <a href="#smpte2052">[SMPTE 2052-11]</a>, §5.4.4.
-This would permit, for example, the interchange of information that reflects the
-the semantics of <a href="#cea708e">[CEA-708-E]</a> , §4.5 “Caption Service Metadata”, “ASPECT RATIO”.</p></div><p>If the <a href="#style-attribute-position"><code>tts:position</code></a> attribute is specified on the <code>tt</code>
-element, then it must adhere to <a href="#style-attribute-position"><b>10.2.27 tts:position</b></a>, in which case it
-specifies the position of the <a href="#terms-root-container-region">root container region</a> relative to a reference positioning area.</p><p>Except for the <code>tts:extent</code> and <code>tts:position</code> attributes described above, an attribute in the TT Style Namespace should not
-be specified on the <code>tt</code> element unless it denotes an inheritable style property, in which case such inheritable style property is available
-for <a href="#semantics-style-inheritance-root">root style inheritance</a>. If a non-inheritable style property is specified, then
-it must be ignored for the purpose of non-validation processing. In the case of validation
-processing, such usage should be reported as a warning, or, if strict validation is performed, as an error.</p><p>An <code>xml:lang</code> attribute must be specified on the <code>tt</code> element.
-If the attribute value is empty, it signifies that there is no default language that applies
-to the text contained within the <a href="#terms-document-instance">document instance</a>.</p><p>If no <code>xml:space</code> attribute is specified upon the <code>tt</code> element, then it must
-be considered as if the attribute had been specified with a value of <code>default</code>.</p></div><div class="div3">
-<h4><a id="document-structure-vocabulary-head"></a>8.1.2 head</h4><p>The <code>head</code> element is a container element used to group header matter, including metadata,
-profile, embedded content resources, styling, and layout information.</p><p>The <code>head</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more elements in the
-<a href="#element-vocab-group-profile"><code>Profile.class</code></a> element group,
-followed by zero or one <a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element,
-followed by zero or one <a href="#styling-vocabulary-styling"><code>styling</code></a> element,
-followed by zero or one <a href="#layout-vocabulary-layout"><code>layout</code></a> element,
-followed by zero or one <a href="#animation-vocabulary-animation"><code>animation</code></a> element.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <a href="#terms-document-instance">document instance</a> as a
-whole, and not just the <code>head</code> element.</p><p>Any parameters specified by children in the <code>Parameters.class</code>
-element group applies semantically to the <a href="#terms-document-instance">document instance</a> as a
-whole, and not just the <code>head</code> element.</p><p>A <code>resources</code> child element is used to specify embedded content constructs
-that are referenced from certain style constructs and
-<a href="#terms-embedded-content-element">embedded content elements</a>.</p><p>A <code>styling</code> child element is used to specify style constructs
-that are referenced from other style constructs, by layout constructs, and by
-<a href="#terms-content-element">content elements</a>.</p><p>A <code>layout</code> child element is used to specify layout constructs that
-are referenced by <a href="#terms-content-element">content elements</a>.</p><p>An <code>animation</code> child element is used to specify animation constructs that
-target animatable <a href="#terms-content-element">content element</a>
-or <a href="#element-vocab-type-layout">Layout</a> elements.</p><a id="elt-syntax-head"></a><table class="syntax"><caption>XML Representation – Element Information Item: head</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;head
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-profile">Profile.class</a>*, <a href="#embedded-content-vocabulary-resources">resources</a>?, <a href="#styling-vocabulary-styling">styling</a>?, <a href="#layout-vocabulary-layout">layout</a>?, <a href="#animation-vocabulary-animation">animation</a>?
-&lt;/head&gt;
-</pre></div>
-</td></tr></tbody></table><p>To the extent that time semantics apply to the content of the
-<code>head</code> element, the implied time interval of this element is
-defined to be coterminous with the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p></div><div class="div3">
-<h4><a id="document-structure-vocabulary-body"></a>8.1.3 body</h4><p>The <code>body</code> element functions as a logical container and a temporal
-structuring element for a sequence of textual content units represented as
-logical divisions.</p><p>The <code>body</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more
-elements in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a> element group,
-followed by
-zero or more <code>div</code> elements.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <code>body</code> element and its descendants as a whole.</p><p>Any animation elements specified by children in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a>
-element group apply semantically to the <code>body</code> element.</p><a id="elt-syntax-body"></a><table class="syntax"><caption>XML Representation – Element Information Item: body</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;body
-  <a href="#animation-attribute-animate">animate</a> = IDREFS
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#layout-attribute-region">region</a> = IDREF
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*, <a href="#content-vocabulary-div">div</a>*
-&lt;/body&gt;
-</pre></div>
-</td></tr></tbody></table><p>An author may specify a temporal interval for a <code>body</code> element using
-the <code>begin</code>, <code>dur</code>, and <code>end</code> attributes. If the begin point
-of this interval remains unspecified, then the begin point is interpreted as the beginning
-point of the <a href="#terms-root-temporal-extent">root temporal extent</a>. Similarly, if the end point of this interval remains unspecified, then the
-end point is interpreted as the ending point of the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <a href="#terms-document-instance">document instance</a> referenced from a SMIL presentation
-is expected to follow the same timing rules as apply to other SMIL media
-objects.</p></div><p>If relative begin or end times are specified on the <code>body</code>
-element, then these times are resolved by reference to the beginning and
-ending time of the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p><p>If the <a href="#terms-root-temporal-extent">root temporal extent</a> is shorter than the computed duration of the
-<code>body</code> element, then the active time interval of a <code>body</code> element is
-truncated to the active end point of the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p><p>An author may associate a set of style properties with a
-<code>body</code> element by means of either the <code>style</code>
-attribute or inline style attributes or a combination thereof.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Style properties that are associated with a <code>body</code> element
-in a <a href="#terms-document-instance">document instance</a> are available for style inheritance by
-descendant <a href="#terms-content-element">content elements</a> such as <code>div</code>, <code>p</code>,
-<code>span</code>
-and <code>br</code>.</p></div><p>If no <code>timeContainer</code> attribute is specified on a
-<code>body</code> element, then it must be interpreted as having
-<em>parallel</em>
-time containment semantics.</p></div><div class="div3">
-<h4><a id="content-vocabulary-div"></a>8.1.4 div</h4><p>The <code>div</code> element functions as a logical container and a temporal
-structuring element for a sequence of textual content units represented as
-logical sub-divisions or paragraphs.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When rendered on a continuous (non-paged) visual presentation medium,
-a <code>div</code> element is expected to generate
-one or more block
-areas
-that contain zero or more child block areas
-generated by the <code>div</code> element's
-descendant
-<code>p</code> elements.
-</p><p>If some
-block area generated by a <code>div</code> element does
-not contain any child areas, then it is not expected to be presented.</p></div><p>The <code>div</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more
-elements in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a> element group,
-followed by zero or one
-element in the <a href="#element-vocab-group-layout"><code>Layout.class</code></a> element group,
-followed by zero or more elements in the <a href="#element-vocab-group-block"><code>Block.class</code></a> or
-<a href="#element-vocab-group-embedded"><code>Embedded.class</code></a> element groups.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <code>div</code> element and its descendants as a whole.</p><p>Any animation elements specified by children in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a>
-element group apply semantically to the <code>div</code> element.</p><a id="elt-syntax-div"></a><table class="syntax"><caption>XML Representation – Element Information Item: div</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;div
-  <a href="#animation-attribute-animate">animate</a> = IDREFS
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#layout-attribute-region">region</a> = IDREF
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*, <a href="#element-vocab-group-layout">Layout.class</a>?, (<a href="#element-vocab-group-block">Block.class</a>|<a href="#element-vocab-group-embedded">Embedded.class</a>)*
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p>An author may associate a set of style properties with a <code>div</code> element by means of either
-the <code>style</code> attribute or inline style attributes or a combination thereof.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Style properties that are associated
-with
-a <code>div</code> element in a <a href="#terms-document-instance">document instance</a>
-are available for style inheritance by descendant <a href="#terms-content-element">content elements</a> such as
-<code>div</code>, 
-<code>p</code>,
-<code>span</code>, and
-<code>br</code>.</p></div><p>If a
-<a href="#style-attribute-position"><code>tts:extent</code></a>,
-<a href="#style-attribute-position"><code>tts:origin</code></a>, or
-<a href="#style-attribute-position"><code>tts:position</code></a>
-style attribute is specified on a <code>div</code> element, then that specification must be considered to be
-equivalent to specifying an anonymous <a href="#terms-inline-region">inline region</a> child of the <code>div</code> element, where the
-extent, origin, or position of the corresponding region, also referred to as an <a href="#terms-implied-inline-region">implied inline region</a>, is equal to the
-value of the respective attribute. If any of these style attributes are specified,
-then they apply to the same <a href="#terms-implied-inline-region">implied inline region</a>.
-If both <a href="#style-attribute-position"><code>tts:origin</code></a> and <a href="#style-attribute-position"><code>tts:position</code></a> attributes
-are specified and <a href="#style-attribute-position"><code>tts:position</code></a> is a supported property,
-then the <a href="#style-attribute-position"><code>tts:origin</code></a> attribute must be ignored when constructing the associated
-<a href="#terms-implied-inline-region">implied inline region</a>.</p><p>If no <code>timeContainer</code> attribute is specified on
-a <code>div</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p></div><div class="div3">
-<h4><a id="content-vocabulary-p"></a>8.1.5 p</h4><p>A <code>p</code> element represents a logical paragraph, serving as
-a transition between block level and inline level formatting semantics.</p><p>The <code>p</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more
-elements in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a> element group,
-followed by zero or one
-element in the <a href="#element-vocab-group-layout"><code>Layout.class</code></a> element group,
-followed by zero or more elements in the <a href="#element-vocab-group-inline"><code>Inline.class</code></a> or
-<a href="#element-vocab-group-embedded"><code>Embedded.class</code></a> element groups.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <code>p</code> element and its descendants as a whole.</p><p>Any animation elements specified by children in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a>
-element group apply semantically to the <code>p</code> element.</p><a id="elt-syntax-p"></a><table class="syntax"><caption>XML Representation – Element Information Item: p</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;p
-  <a href="#animation-attribute-animate">animate</a> = IDREFS
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#layout-attribute-region">region</a> = IDREF
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*, <a href="#element-vocab-group-layout">Layout.class</a>?, (<a href="#element-vocab-group-inline">Inline.class</a>|<a href="#element-vocab-group-embedded">Embedded.class</a>)*
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p>An author may associate a set of style properties with a
-<code>p</code> element by means of either the <code>style</code>
-attribute or inline style attributes or a combination thereof.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Style properties that are associated with a <code>p</code> element
-in a <a href="#terms-document-instance">document instance</a> are available for style inheritance by
-descendant <a href="#terms-content-element">content elements</a> such as <code>span</code> and
-<code>br</code>.</p></div><p>If a
-<a href="#style-attribute-position"><code>tts:extent</code></a>,
-<a href="#style-attribute-position"><code>tts:origin</code></a>, or
-<a href="#style-attribute-position"><code>tts:position</code></a>
-style attribute is specified on a <code>p</code> element, then that specification must be considered to be
-equivalent to specifying an anonymous <a href="#terms-inline-region">inline region</a> child of the <code>p</code> element, where the
-extent, origin, or position of the corresponding region, also referred to as an <a href="#terms-implied-inline-region">implied inline region</a>, is equal to the
-value of the respective attribute. If any of these style attributes are specified,
-then they apply to the same <a href="#terms-implied-inline-region">implied inline region</a>.
-If both <a href="#style-attribute-position"><code>tts:origin</code></a> and <a href="#style-attribute-position"><code>tts:position</code></a> attributes
-are specified and <a href="#style-attribute-position"><code>tts:position</code></a> is a supported property,
-then the <a href="#style-attribute-position"><code>tts:origin</code></a> attribute must be ignored when constructing the associated
-<a href="#terms-implied-inline-region">implied inline region</a>.</p><p>If no <code>timeContainer</code> attribute is specified on
-a <code>p</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p><p>If a sequence of children of a <code>p</code> element
-consists solely of <a href="#terms-character-information-item">character information items</a>, then that sequence must
-be considered to be an <em>anonymous span</em> for the purpose of
-applying style properties that apply to <code>span</code> elements.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The presentation semantics of TTML effectively
-implies that a <code>p</code> element constitutes a line break. In particular,
-it is associated with a block-stacking constraint both before the first
-generated line area and after the last generated line area. See
-<a href="#semantics-region-layout-step-2"><b>11.3.1.4 Synchronic Flow Processing</b></a> for further details.</p></div></div><div class="div3">
-<h4><a id="content-vocabulary-span"></a>8.1.6 span</h4><p>The <code>span</code> element functions as a logical container and a temporal
-structuring element for a sequence of textual content units having inline
-level formatting semantics.</p><p>When presented on a visual medium, a <code>span</code> element is intended to
-generate a sequence of inline areas, each containing one or more glyph areas.</p><p>The <code>span</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more
-elements in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a> element group,
-followed by zero or more elements in the <a href="#element-vocab-group-inline"><code>Inline.class</code></a> or
-<a href="#element-vocab-group-embedded"><code>Embedded.class</code></a> element groups.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <code>span</code> element and its descendants as a whole.</p><p>Any animation elements specified by children in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a>
-element group apply semantically to the <code>span</code> element.</p><a id="elt-syntax-span"></a><table class="syntax"><caption>XML Representation – Element Information Item: span</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;span
-  <a href="#animation-attribute-animate">animate</a> = IDREFS
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#layout-attribute-region">region</a> = IDREF
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#content-attribute-xlink-arcrole">xlink:arcrole</a> = <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>+
-  <a href="#content-attribute-xlink-href">xlink:href</a> = <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-  <a href="#content-attribute-xlink-role">xlink:role</a> = <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>+
-  <a href="#content-attribute-xlink-show">xlink:show</a> = (<em>new</em>|<em>replace</em>|<em>embed</em>|<em>other</em>|<em>none</em>) : new
-  <a href="#content-attribute-xlink-title">xlink:title</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*, (<a href="#element-vocab-group-inline">Inline.class</a>|<a href="#element-vocab-group-embedded">Embedded.class</a>)*
-&lt;/span&gt;
-</pre></div>
-</td></tr></tbody></table><p>An author may associate a set of style properties with a
-<code>span</code> element by means of either the <code>style</code>
-attribute or inline style attributes or a combination thereof.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Style properties that are associated with a <code>span</code> element
-in a <a href="#terms-document-instance">document instance</a> are available for style inheritance by
-descendant <a href="#terms-content-element">content elements</a> such as <code>span</code> and
-<code>br</code>.</p></div><p>If no <code>timeContainer</code> attribute is specified on
-a <code>span</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p><p>The linking attributes <code>xlink:*</code> may be used to link a <code>span</code> element with related content, using the
-specified location (<code>href</code>), roles, and title. The behavior of link activation is affected by the <code>xlink:show</code> attribute,
-the precise meaning of which is determined by the <a href="#terms-document-processing-context">document processing context</a>.</p><p>If a <code>span</code> element specifies an <code>xlink:href</code> attribute, then a nested <code>span</code> element descendant must not specify
-an <code>xlink:href</code> attribute, and, if it does, then the latter must be ignored for the purpose of presentation or activation processing.</p></div><div class="div3">
-<h4><a id="content-vocabulary-br"></a>8.1.7 br</h4><p>The <code>br</code> element denotes an explicit line break.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <code>br</code> element and its descendants as a whole.</p><p>Any animation elements specified by children in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a>
-element group apply semantically to the <code>br</code> element.</p><a id="elt-syntax-br"></a><table class="syntax"><caption>XML Representation – Element Information Item: br</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;br
-  <a href="#animation-attribute-animate">animate</a> = IDREFS
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#layout-attribute-region">region</a> = IDREF
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*
-&lt;/br&gt;
-</pre></div>
-</td></tr></tbody></table><p>When presented on a visual medium, the presence of a <code>br</code> element must be
-interpreted as a forced line break.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The visual presentation of a <code>br</code> element is
-intended to produce the same effect as the control character
-<code>CR</code> (U+000D)
-followed by the control code <code>LF</code> (U+000A) when presented on a teletype device.
-Therefore, two <code>br</code> elements in sequence will produce a
-different effect than a single <code>br</code> element.</p></div><p>If no <code>timeContainer</code> attribute is specified on
-a <code>br</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p></div></div><div class="div2">
-<h3><a id="content-attribute-vocabulary"></a>8.2 Content Attribute Vocabulary</h3><p>This section defines the following common attributes used with many or all element types
-in the core vocabulary catalog:</p><ul><li><p><a href="#content-attribute-condition"><b>8.2.1 condition</b></a></p></li><li><p><a href="#content-attribute-xml-id"><b>8.2.7 xml:id</b></a></p></li><li><p><a href="#content-attribute-xml-lang"><b>8.2.8 xml:lang</b></a></p></li><li><p><a href="#content-attribute-xml-space"><b>8.2.9 xml:space</b></a></p></li></ul><p>In addition, this section defines the following linking vocabulary used by certain element types
-in the core vocabulary catalog:</p><ul><li><p><a href="#content-attribute-xlink-arcrole"><b>8.2.2 xlink:arcrole</b></a></p></li><li><p><a href="#content-attribute-xlink-href"><b>8.2.3 xlink:href</b></a></p></li><li><p><a href="#content-attribute-xlink-role"><b>8.2.4 xlink:role</b></a></p></li><li><p><a href="#content-attribute-xlink-show"><b>8.2.5 xlink:show</b></a></p></li><li><p><a href="#content-attribute-xlink-title"><b>8.2.6 xlink:title</b></a></p></li></ul><div class="div3">
-<h4><a id="content-attribute-condition"></a>8.2.1 condition</h4><p>The <code>condition</code> attribute is used to conditionally exclude an element from semantic processing.</p><p>The <code>condition</code> attribute may be used with any element in the core vocabulary catalog
-except profile matter, i.e., elements of the <a href="#element-vocab-type-profile">Profile Module</a>.</p><p>The value of a <code>condition</code> attribute must adhere to a
-<a href="#content-value-condition">&lt;condition&gt;</a> expression.</p><p>For the purpose of presentation processing, if an element specifies a <code>condition</code> attribute, and the
-its <a href="#content-value-condition">&lt;condition&gt;</a> expression value evaluates to <code>false</code>,
-then the semantics of the element and its descendant elements must be ignored.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, if a <a href="#content-vocabulary-p"><code>p</code></a> element specifies a <code>condition</code>
-attribute that evaluates to <code>false</code>, then the content of that element is ignored for presentation purposes.</p></div></div><div class="div3">
-<h4><a id="content-attribute-xlink-arcrole"></a>8.2.2 xlink:arcrole</h4><p>The <code>xlink:arcrole</code> attribute is used as defined by <a href="#xlink11">[XLink 1.1]</a>.</p><p>The <code>xlink:arcrole</code> attribute may be used with any <a href="#content-vocabulary-span"><code>span</code></a> or
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element.</p></div><div class="div3">
-<h4><a id="content-attribute-xlink-href"></a>8.2.3 xlink:href</h4><p>The <code>xlink:href</code> attribute is used as defined by <a href="#xlink11">[XLink 1.1]</a>.</p><p>The <code>xlink:href</code> attribute may be used with any <a href="#content-vocabulary-span"><code>span</code></a> or
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element.</p></div><div class="div3">
-<h4><a id="content-attribute-xlink-role"></a>8.2.4 xlink:role</h4><p>The <code>xlink:role</code> attribute is used as defined by <a href="#xlink11">[XLink 1.1]</a>.</p><p>The <code>xlink:role</code> attribute may be used with any <a href="#content-vocabulary-span"><code>span</code></a> or
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element.</p></div><div class="div3">
-<h4><a id="content-attribute-xlink-show"></a>8.2.5 xlink:show</h4><p>The <code>xlink:show</code> attribute is used as defined by <a href="#xlink11">[XLink 1.1]</a>.</p><p>The <code>xlink:show</code> attribute may be used with any <a href="#content-vocabulary-span"><code>span</code></a> or
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element.</p></div><div class="div3">
-<h4><a id="content-attribute-xlink-title"></a>8.2.6 xlink:title</h4><p>The <code>xlink:title</code> attribute is used as defined by <a href="#xlink11">[XLink 1.1]</a>.</p><p>The <code>xlink:title</code> attribute may be used with any <a href="#content-vocabulary-span"><code>span</code></a> or
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element.</p></div><div class="div3">
-<h4><a id="content-attribute-xml-id"></a>8.2.7 xml:id</h4><p>The <code>xml:id</code> attribute is used as defined by
-<a href="#xmlid">[XML ID]</a>.</p><p>The <code>xml:id</code> attribute may be used with any element in the core vocabulary catalog.</p></div><div class="div3">
-<h4><a id="content-attribute-xml-lang"></a>8.2.8 xml:lang</h4><p>The <code>xml:lang</code> attribute is used as defined by
-<a href="#xml10">[XML 1.0]</a>, §2.12, <em>Language Identification</em>.</p><p>The <code>xml:lang</code> attribute must be specified on the <code>tt</code>
-element and may be specified by an instance of any other element type
-in the core vocabulary catalog except parameter vocabulary.</p></div><div class="div3">
-<h4><a id="content-attribute-xml-space"></a>8.2.9 xml:space</h4><p>The <code>xml:space</code> attribute is used as defined by
-<a href="#xml10">[XML 1.0]</a>, §2.10, <em>White Space Handling</em>.</p><p>The <code>xml:space</code> attribute may be used with any element in
-the core vocabulary catalog except parameter vocabulary.</p><p>The semantics of the value <code>default</code> are fixed to mean that
-when performing presentation processing of a <a href="#terms-document-instance">document instance</a> as
-described by <a href="#semantics-region-layout-step-2"><b>11.3.1.4 Synchronic Flow Processing</b></a>,
-processing must occur as
-if the following properties were specified on the affected
-elements of an equivalent intermediate XSL-FO document:</p><ul><li><p><code>suppress-at-line-break="auto"</code></p></li><li><p><code>linefeed-treatment="treat-as-space"</code></p></li><li><p><code>white-space-collapse="true"</code></p></li><li><p><code>white-space-treatment="ignore-if-surrounding-linefeed"</code></p></li></ul><p>Similarly, the semantics of the value <code>preserve</code> are fixed to mean that
-when performing presentation processing, processing must occur as
-if the following properties were specified on the affected
-elements of an equivalent intermediate XSL-FO document:
-</p><ul><li><p><code>suppress-at-line-break="retain"</code></p></li><li><p><code>linefeed-treatment="preserve"</code></p></li><li><p><code>white-space-collapse="false"</code></p></li><li><p><code>white-space-treatment="preserve"</code></p></li></ul><p>When performing other types of processing intended to eventually
-result in a visual presentation by means other than those described
-in this specification, the semantics of space collapsing and
-preservation as described above should be respected. For other types
-of processing, the treatment of the <code>xml:space</code> attribute
-is processor dependent, but should respect the semantics described
-above if possible.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the above four cited XSL-FO properties are defined by
-by <a href="#xsl11">[XSL 1.1]</a>, § 7.17.3, 7.16.7, 7.16.12, and 7.16.8, respectively.</p></div></div></div><div class="div2">
-<h3><a id="content-value-expressions"></a>8.3 Content Value Expressions</h3><p>Core vocabulary may make use of the following expressions:</p><ul><li><p><a href="#content-value-arguments"><b>8.3.1 &lt;arguments&gt;</b></a></p></li><li><p><a href="#content-value-bound-parameter"><b>8.3.2 &lt;bound-parameter&gt;</b></a></p></li><li><p><a href="#content-value-condition"><b>8.3.3 &lt;condition&gt;</b></a></p></li><li><p><a href="#content-value-condition-function"><b>8.3.4 &lt;condition-function&gt;</b></a></p></li><li><p><a href="#content-value-expression"><b>8.3.5 &lt;expression&gt;</b></a></p></li><li><p><a href="#content-value-media-function"><b>8.3.6 &lt;media-function&gt;</b></a></p></li><li><p><a href="#content-value-parameter-function"><b>8.3.8 &lt;parameter-function&gt;</b></a></p></li><li><p><a href="#content-value-quoted-string"><b>8.3.7 &lt;quoted-string&gt;</b></a></p></li><li><p><a href="#content-value-supports-function"><b>8.3.9 &lt;supports-function&gt;</b></a></p></li></ul><div class="div3">
-<h4><a id="content-value-arguments"></a>8.3.1 &lt;arguments&gt;</h4><p>A &lt;arguments&gt; value is a sub-expression used with a <code>function-expression</code> non-terminal of an
-<a href="#content-value-expression">&lt;expression&gt;</a> value.</p><a id="arguments-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;arguments&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;arguments&gt;
-  : "(" ")"
-  | "(" argument-list ")"
-
-argument-list
-  : <a href="#content-value-expression">&lt;expression&gt;</a>
-  | argument-list "," <a href="#content-value-expression">&lt;expression&gt;</a>
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="content-value-bound-parameter"></a>8.3.2 &lt;bound-parameter&gt;</h4><p>A &lt;bound-parameter&gt; value is one of an enumerated collection of named parameters bound to a value by the
-<a href="#terms-content-processor">content processor</a>.</p><a id="bound-parameter-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;bound-parameter&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;bound-parameter&gt;
-  : forced
-  | mediaAspectRatio
-  | mediaLanguage
-  | userLanguage
-</pre></div>
-</td></tr></tbody></table><dl><dt class="label"><a id="bound-parameter-forced"></a><code>forced</code></dt><dd><p>Evaluates to a boolean value that denotes if the <a href="#terms-content-processor">content processor</a> is operating with
-<a href="#terms-forced-subtitle">forced subtitles</a> enabled.</p></dd><dt class="label"><a id="bound-parameter-mediaAspectRatio"></a><code>mediaAspectRatio</code></dt><dd><p>Evaluates to a numeric value equal to the aspect ratio of the <a href="#terms-related-media-object">related media object</a>.</p></dd><dt class="label"><a id="bound-parameter-mediaLanguage"></a><code>mediaLanguage</code></dt><dd><p>Evaluates to a string value equal to the (primary) language of the <a href="#terms-related-media-object">related media object</a>.</p></dd><dt class="label"><a id="bound-parameter-userLanguage"></a><code>userLanguage</code></dt><dd><p>Evaluates to a string value equal to the (primary) language of the user as determined by the
-<a href="#terms-document-processing-context">document processing context</a>.</p></dd></dl></div><div class="div3">
-<h4><a id="content-value-condition"></a>8.3.3 &lt;condition&gt;</h4><p>A &lt;condition&gt; value is used to specify an expression that evaluates to a binary value
-which is used to determine if the semantics of a
-<a href="#terms-conditionalized-element">conditionalized element</a> is respected or ignored during content processing.</p><a id="condition-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;condition&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;condition&gt;
-  : <a href="#content-value-expression">&lt;expression&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>If a &lt;condition&gt; value contains a <code>function-expression</code> non-terminal, then it must take the form
-of a <a href="#content-value-condition-function">&lt;condition-function&gt;</a> expression.</p></div><div class="div3">
-<h4><a id="content-value-condition-function"></a>8.3.4 &lt;condition-function&gt;</h4><p>A &lt;condition-function&gt; value is a sub-expression that may be used in a <a href="#content-value-condition">&lt;condition&gt;</a> value expression.</p><a id="condition-function-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;condition-function&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;condition-function&gt;
-  | <a href="#content-value-media-function">&lt;media-function&gt;</a>
-  | <a href="#content-value-parameter-function">&lt;parameter-function&gt;</a>
-  | <a href="#content-value-supports-function">&lt;supports-function&gt;</a>
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="content-value-expression"></a>8.3.5 &lt;expression&gt;</h4><p>An &lt;expression&gt; value is a sub-expression of a <a href="#content-value-condition">&lt;condition&gt;</a> value.</p><a id="expression-value-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;expression&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;expression&gt;
-  : logical-or-expression
-
-logical-or-expression
-  : logical-and-expression
-  | logical-or-expression "||" logical-and-expression
-
-logical-and-expression
-  : equality-expression
-  | logical-and-expression "&amp;&amp;" equality-expression
-
-equality-expression
-  : relational-expression
-  | equality-expression "==" relational-expression
-  | equality-expression "!=" relational-expression
-
-relational-expression
-  : additive-expression
-  | relational-expression "&lt;" additive-expression
-  | relational-expression "&gt;" additive-expression
-  | relational-expression "&lt;=" additive-expression
-  | relational-expression "&gt;=" additive-expression
-
-additive-expression
-  : multiplicitive-expression
-  | additive-expression "+" multiplicitive-expression
-  | additive-expression "-" multiplicitive-expression
-
-multiplicitive-expression
-  : unary-expression
-  | multiplicitive-expression "*" unary-expression
-  | multiplicitive-expression "/" unary-expression
-  | multiplicitive-expression "%" unary-expression
-
-unary-expression
-  : primary-or-function-expression
-  | "+" unary-expression
-  | "-" unary-expression
-  | "!" unary-expression
-
-primary-or-function-expression
-  : primary-expression
-  | function-expression
-
-primary-expression
-  : identifier
-  | literal
-  | "(" expression ")"
-
-function-expression
-  : identifier <a href="#content-value-arguments">&lt;arguments&gt;</a>
-
-identifier
-  : <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-
-literal
-  : boolean-literal
-  | numeric-literal
-  | string-literal
-
-boolean-literal
-  : "true"
-  | "false"
-
-numeric-literal
-  : decimal-literal
-
-decimal-literal
-  : decimal-integer-literal "." decimal-digits? exponent-part?
-  | "." decimal-digits exponent-part?
-  | decimal-integer-literal exponent-part?
-
-decimal-integer-literal
-  : "0"
-  | non-zero-digit decimal-digits?
-
-decimal-digits
-  : decimal-digit
-  | decimal-digits decimal-digit
-
-decimal-digit
-  : "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8"
-
-non-zero-digit
-  : "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8"
-
-exponent-part
-  : exponent-indicator signed-integer
-
-exponent-indicator
-  : "e" | "E"
-
-signed-integer
-  : decimal-digits
-  | "+" decimal-digits
-  | "-" decimal-digits
-
-string-literal
-  : <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="content-value-media-function"></a>8.3.6 &lt;media-function&gt;</h4><p>A &lt;media-function&gt; value is a sub-expression that may be used in a <a href="#content-value-condition">&lt;condition&gt;</a> value expression
-in order to perform a media query on the <a href="#terms-related-media-object">related media object</a> or the
-<a href="#terms-document-processing-context">document processing context</a>.</p><a id="media-function-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;media-function&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;media-function&gt;
-  : "media" "(" media-query ")"
-
-media-query
-  : <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>The <code>media-query</code> argument of a &lt;media-function&gt; value expression must adhere to
-the syntax of the <code>media_query_list</code> defined by <a href="#media-queries">[Media Queries]</a>, § 3.</p><p>A &lt;media-function&gt; value expression evaluates to <code>true</code> if the specified media query
-evaluates to <code>true</code>, otherwise, the value expression evaluates to <code>false</code>.</p></div><div class="div3">
-<h4><a id="content-value-quoted-string"></a>8.3.7 &lt;quoted-string&gt;</h4><p>A &lt;quoted-string&gt; value expression is used to specify a double or single quoted string.</p><a id="quoted-string-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;quoted-string&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;quoted-string&gt;
-  : double-quoted-string
-  | single-quoted-string
-
-double-quoted-string
-  : '"' ( [^"\\] | escape )+ '"'
-
-single-quoted-string
-  : "'" ( [^'\\] | escape )+ "'"
-
-escape
-  : '\\' <em>char</em>
-</pre></div>
-
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="content-value-parameter-function"></a>8.3.8 &lt;parameter-function&gt;</h4><p>A &lt;parameter-function&gt; value is a sub-expression that may be used in a <a href="#content-value-condition">&lt;condition&gt;</a> value expression
-in order to obtain a named parameter of the <a href="#terms-document-processing-context">document processing context</a>.</p><a id="parameter-function-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;parameter-function&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;parameter-function&gt;
-  : "parameter" "(" parameter-name ")"
-
-parameter-name
-  : <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>When de-quoted, the <code>parameter-name</code> argument of a &lt;parameter-function&gt; value expression must adhere to an
-<a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>, which must, in turn, be one of the values enumerated
-by <a href="#content-value-bound-parameter">&lt;bound-parameter&gt;</a>.</p><p>A &lt;parameter-function&gt; value expression evaluates to the value associated with (bound to) the
-specified paramater name.</p></div><div class="div3">
-<h4><a id="content-value-supports-function"></a>8.3.9 &lt;supports-function&gt;</h4><p>A &lt;supports-function&gt; value is a sub-expression that may be used in a <a href="#content-value-condition">&lt;condition&gt;</a> value expression
-in order to obtain a boolean value that denotes whether a specified <a href="#terms-feature">feature</a> or <a href="#terms-extension">extension</a>
-is supported or not.</p><a id="supports-function-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;supports-function&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;supports-function&gt;
-  : "supports" "(" feature-or-extension-designator ")"
-
-feature-or-extension-designator
-  : <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>The <code>feature-or-extension-designator</code> argument of a &lt;supports-function&gt; value expression must express
-a feature designation or an extension designation as defined by
-<a href="#feature-designations"><b>E.1 Feature Designations</b></a> and <a href="#extension-designations"><b>F.1 Extension Designations</b></a>, respectively, and where the
-<code>feature-namespace</code> or <code>extension-namespace</code> component of the designation is optional, and, if
-not specified, is considered to be equal to the <em>TT Feature Namespace</em> or <em>TT Extension Namespace</em>,
-respectively.</p><p>A &lt;supports-function&gt; value expression evaluates to <code>true</code> if the specified feature or extension
-designator is (semantically) supported by the <a href="#terms-content-processor">content processor</a>.</p></div></div></div><div class="div1">
-<h2><a id="embedded-content"></a>9 Embedded Content</h2><p>This section specifies the <em>embedded content</em> matter of the core
-vocabulary catalog, where, in this context,
-<em>content</em> is to be understood as data of an arbitrary content type (format)
-and <em>embedded</em> refers to the embedding (inlining) of this data or the embedding
-of a reference to external data.</p><div class="div2">
-<h3><a id="embedded-content-element-vocabulary"></a>9.1 Embedded Content Element Vocabulary</h3><p>The following elements may be used to specify embedded content:</p><ul><li><p><a href="#embedded-content-vocabulary-audio"><b>9.1.1 audio</b></a></p></li><li><p><a href="#embedded-content-vocabulary-chunk"><b>9.1.2 chunk</b></a></p></li><li><p><a href="#embedded-content-vocabulary-data"><b>9.1.3 data</b></a></p></li><li><p><a href="#embedded-content-vocabulary-font"><b>9.1.4 font</b></a></p></li><li><p><a href="#embedded-content-vocabulary-image"><b>9.1.5 image</b></a></p></li><li><p><a href="#embedded-content-vocabulary-resources"><b>9.1.6 resources</b></a></p></li><li><p><a href="#embedded-content-vocabulary-source"><b>9.1.7 source</b></a></p></li></ul><p>The <a href="#embedded-content-vocabulary-data"><b>9.1.3 data</b></a> element serves as
-a generic container element for an <a href="#terms-embedded-data-resource">embedded data resource</a>, which may or may not be fragmented into chunks,
-in which case a data fragment is represented using the <a href="#embedded-content-vocabulary-chunk"><b>9.1.2 chunk</b></a> element.
-The <a href="#embedded-content-vocabulary-audio"><b>9.1.1 audio</b></a>,
-<a href="#embedded-content-vocabulary-font"><b>9.1.4 font</b></a>, and
-<a href="#embedded-content-vocabulary-image"><b>9.1.5 image</b></a> elements are specialized elements used to
-to reference specific types of embedded content.
-The <a href="#embedded-content-vocabulary-resources"><b>9.1.6 resources</b></a> element is used to
-group definitions of embedded content for reference by subsequent elements.
-The <a href="#embedded-content-vocabulary-source"><b>9.1.7 source</b></a> element may be used to
-express the source of embedded content.</p><div class="div3">
-<h4><a id="embedded-content-vocabulary-audio"></a>9.1.1 audio</h4><p>The <code>audio</code> element is used to define an author supplied <a href="#terms-audio-resource">audio resource</a>.</p><p>An <code>audio</code> element may appear in two contexts: (1) as a child of a <a href="#embedded-content-vocabulary-resource"><code>resource</code></a> element and
-(2) as a child of an element in the <a href="#element-vocab-group-block">Block.class</a> element group, namely, as a child of a
-<a href="#content-vocabulary-div"><code>div</code></a> or <a href="#content-vocabulary-p"><code>p</code></a> element, or
-as a child of a <a href="#content-vocabulary-span"><code>span</code></a> element. The former is referred to as an
-<a href="#terms-audio-defining-context">audio defining context</a>, the latter as an <a href="#terms-audio-presentation-context">audio presentation context</a>.</p><p>When an <code>audio</code> element appears in an <a href="#terms-audio-defining-context">audio defining context</a>, it
-serves as a sharable definition of an <a href="#terms-audio-resource">audio resource</a> that may be referenced by other <code>audio</code> elements in the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a>. In this case, the active time interval of the <code>audio</code> element
-is the same as the active time interval of its parent <a href="#embedded-content-vocabulary-resource"><code>resource</code></a> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A sharable definition of an <a href="#terms-audio-resource">audio resource</a> specifies an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute in order to be referenced
-by <code>audio</code> elements in an <a href="#terms-audio-presentation-context">audio presentation context</a>.</p></div><p>When an <code>audio</code> element appears in an <a href="#terms-audio-presentation-context">audio presentation context</a>, it
-serves as a non-sharable definition of an <a href="#terms-audio-resource">audio resource</a> that implies presentation (rendering) semantics, i.e., that it is intended to be played.
-In this case, the active time interval of the <code>audio</code> element is the same as the active time interval of its parent
-<a href="#terms-content-element">content element</a>.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A non-sharable definition of an <a href="#terms-audio-resource">audio resource</a> may or may not specify an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute, but this
-identifier is not referenced by other <code>audio</code> elements, or, if it is, the reference is ignored.</p></div><p>The <code>audio</code> element accepts as its children
-zero or more elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group followed by zero or more
-<a href="#embedded-content-vocabulary-source"><code>source</code></a> elements.</p><a id="elt-syntax-audio"></a><table class="syntax"><caption>XML Representation – Element Information Item: audio</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;audio
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#embedded-content-attribute-format">format</a> = <a href="#embedded-content-value-audio-format">&lt;audio-format&gt;</a>
-  <a href="#embedded-content-attribute-src">src</a> = <a href="#embedded-content-value-audio">&lt;audio&gt;</a>
-  <a href="#embedded-content-attribute-type">type</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#embedded-content-vocabulary-source">source</a>*
-&lt;/audio&gt;
-</pre></div>
-</td></tr></tbody></table><p>An <code>audio</code> element defines an <a href="#terms-audio-resource">audio resource</a> either (1) by referring to an <a href="#terms-external-data-resource">external data resource</a>
-or (2) defining or referring to an <a href="#terms-embedded-data-resource">embedded data resource</a>, where the <a href="#terms-data-resource">data resource</a>
-contains audio content.</p><p>If an <code>audio</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must not specify a
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element. Conversely,
-if an <code>audio</code> element does not specify a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must specify one or more
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> elements.</p><p>If an <code>audio</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute and its value does not refer to a fragment of the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a>, then it should specify a
-a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute, in which case the value of the
-<a href="#embedded-content-attribute-type"><code>type</code></a> attribute must correspond with the media (content) type
-of the referenced resource. Otherwise, a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute must not be specified.</p><p>If a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute is not specified or is specified as a generic type, such as <code>application/octet-stream</code>,
-and additional format information is known about a referenced <a href="#terms-audio-resource">audio resource</a>, then a <a href="#embedded-content-attribute-format"><code>format</code></a> attribute should be specified as a hint to the
-content processor.</p><p>If an <code>audio</code> element includes a child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element, then
-the <a href="#embedded-content-attribute-format"><code>format</code></a> attribute of the <code>source</code> child, if specified, must adhere to the <a href="#embedded-content-value-audio-format">&lt;audio-format&gt;</a>
-value expression.</p><p>The use of the <code>audio</code> element is illustrated by the following example.</p><a id="embedded-content-vocabulary-audio-example-1"></a><table class="example"><caption>Example Fragment – External Audio Resource</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;audio src="http://example.com/audio/description.mp3" type="audio/mp3"/&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p></div><div class="div3">
-<h4><a id="embedded-content-vocabulary-chunk"></a>9.1.2 chunk</h4><p>The <code>chunk</code> element is used to represent a distinct chunk (fragment) of data.</p><p>A <code>chunk</code> element may appear as a child of a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element.</p><a id="elt-syntax-chunk"></a><table class="syntax"><caption>XML Representation – Element Information Item: chunk</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;chunk
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#embedded-content-attribute-encoding">encoding</a> = (base16|base32|base32hex|base64|base64url) : base64
-  length = <a href="http://www.w3.org/TR/xmlschema-2/#nonNegativeInteger">xsd:nonNegativeInteger</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/chunk&gt;
-</pre></div>
-</td></tr></tbody></table><p>If an <a href="#embedded-content-attribute-encoding"><code>encoding</code></a> attribute is specified, then it must denote the actual encoding of the byte sequence represented by the
-<code>chunk</code> element. If no <a href="#embedded-content-attribute-encoding"><code>encoding</code></a> attribute is specified, then the encoding must be considered to be <code>base64</code>.</p><p>If a <code>length</code> attribute is specified, then it must denote the number of decoded bytes in the byte sequence represented by the
-<code>chunk</code> element. When decoding, if a specified length value does not match the number of decoded bytes, then the chunk and its container <code>data</code>
-element must return a zero length byte sequence.
-If no <code>length</code> attribute is specified, then the chunk is considered to have a length equal to the actual number of decoded bytes.</p><p>The use of chunked data is illustrated by the following example.</p><a id="embedded-content-vocabulary-chunk-example-1"></a><table class="example"><caption>Example Fragment – Chunked Data</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;data type="text/plain; charset=us-ascii" length="44"&gt;
-  &lt;chunk length="19"&gt;
-    VGhlIHF1aWNrIGJyb3duIGZveA==
-  &lt;/chunk&gt;
-  &lt;chunk length="25"&gt;
-    IGp1bXBzIG92ZXIgdGhlIGxhenkgZG9nLg==
-  &lt;/chunk&gt;
-&lt;/data&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p></div><div class="div3">
-<h4><a id="embedded-content-vocabulary-data"></a>9.1.3 data</h4><p>The <code>data</code> element functions as a generic container for or reference to arbitrary data.</p><p>A <code>data</code> element may appear in three contexts:
-(1) as a child of a <a href="#embedded-content-vocabulary-resource"><code>resource</code></a> element,
-referred to as a <a href="#terms-data-defining-context">data defining context</a>,
-(2) as a child of a <a href="#metadata-vocabulary-metadata"><code>metadata</code></a> element,
-referred to as a <a href="#terms-data-binding-context-for-metadata">data binding context for metadata</a>, or
-(3) as a child of a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element,
-referred to as a <a href="#terms-data-binding-context-for-source">data binding context for source</a>,
-and where these latter two contexts are referred to collectively as <a href="#terms-data-binding-context">data binding contexts</a>.</p><p>When a <code>data</code> element appears in a <a href="#terms-data-defining-context">data defining context</a>, it
-serves as a sharable definition of a data resource that may be referenced by the <a href="#embedded-content-attribute-src"><code>src</code></a> attribute of
-(1) another <code>data</code> element,
-(2) an <a href="#terms-embedded-content-element">embedded content element</a>, or
-(3) a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element.
-In this case, the contextualized active time interval of the <code>data</code> element is the intersection of
-the active time interval of its parent <a href="#embedded-content-vocabulary-resource"><code>resource</code></a> element and
-the active time interval of its referring element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A sharable definition of a data resource specifies an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute in order to be referenced
-by a fragment identifier used in a <a href="#terms-data-binding-context">data binding context</a>.</p></div><p>When a <code>data</code> element appears in a <a href="#terms-data-binding-context">data binding context</a>, it
-serves as a non-sharable definition of a data resource that implies binding semantics, i.e., that it is intended to bound to (associated with) its immediate context
-of reference. In this case, the active time interval of the <code>data</code> element is the same as the active time interval of its closest ancestor timed element.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A non-sharable definition of a data resource may or may not specify an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute, but this
-identifier is not referenced in other <a href="#terms-data-binding-context">data binding contexts</a>, or, if it is, has no binding semantics.</p></div><p>The <code>data</code> element accepts one of the following three content models:
-(1) one or more text nodes (i.e., <code>#PCDATA</code>),
-(2) zero or more elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group followed by one or more
-<a href="#embedded-content-vocabulary-chunk"><code>chunk</code></a> elements, or
-(3) zero or more elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group followed by one or more
-<a href="#embedded-content-vocabulary-source"><code>source</code></a> elements, where
-the first is referred to as <a href="#terms-simple-data-embedding">simple data embedding</a>,
-the second as <a href="#terms-chunked-data-embedding">chunked data embedding</a>, and
-the third as <a href="#terms-sourced-data-embedding">sourced data embedding</a>.</p><p>When <a href="#terms-simple-data-embedding">simple data embedding</a> is used, the data resource is obtained by decoding the <code>#PCDATA</code> content.
-When <a href="#terms-chunked-data-embedding">chunked data embedding</a> is used, the data resource is obtained by concatenating the byte sequences obtained by decoding each
-child <a href="#embedded-content-vocabulary-chunk"><code>chunk</code></a> element.
-When <a href="#terms-simple-data-embedding">sourced data embedding</a> is used, the data resource is obtained from the the first resolvable
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element. Furthermore,
-a child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element must not
-contain a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element, but may refer to a
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element in a <a href="#terms-data-defining-context">data defining context</a>.</p><a id="elt-syntax-data"></a><table class="syntax"><caption>XML Representation – Element Information Item: data</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;data
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#embedded-content-attribute-encoding">encoding</a> = (base16|base32|base32hex|base64|base64url) : <em>see prose below</em>
-  <a href="#embedded-content-attribute-format">format</a> = <a href="#embedded-content-value-data-format">&lt;data-format&gt;</a>
-  length = <a href="http://www.w3.org/TR/xmlschema-2/#nonNegativeInteger">xsd:nonNegativeInteger</a>
-  <a href="#embedded-content-attribute-src">src</a> = <a href="#embedded-content-value-data">&lt;data&gt;</a>
-  <a href="#embedded-content-attribute-type">type</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a> : <em>see prose below</em>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA | (<a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#embedded-content-vocabulary-chunk">chunk</a>+) | (<a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#embedded-content-vocabulary-source">source</a>+)
-&lt;/data&gt;
-</pre></div>
-</td></tr></tbody></table><p>If simple data embedding is used, i.e., the content of the <code>data</code> element is one or more text nodes, then an
-<a href="#embedded-content-attribute-encoding"><code>encoding</code></a> attribute
-may be specified, and, if not specified, must be considered to be <code>base64</code>.
-If chunked or sourced data embedding is used, i.e., the content of the <code>data</code> element contains any child
-<a href="#embedded-content-vocabulary-chunk">chunk</a> or <a href="#embedded-content-vocabulary-source">source</a> element, then
-an <a href="#embedded-content-attribute-encoding"><code>encoding</code></a> attribute must not be specified, and, if specified, must be ignored
-for the purpose of content processing.</p><p>If a <code>length</code> attribute is specified, then it must denote the number of decoded bytes in the byte sequence represented by the
-<code>data</code> element. When decoding, if a specified length value does not match the number of decoded bytes, then a zero length byte sequence must be returned.
-If no <code>length</code> attribute is specified, then the data resource is considered to have a length equal to the actual number of decoded bytes.
-A <code>length</code> attribute must not be specified when using sourced data embedding.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The intention of the <code>length</code> attribute is to provide a means to perform a simple integrity check on decoded data. Note that this check does not guarantee
-data integrity during transport, i.e., the data could be modified without modifying the length.</p></div><p>If simple or chunked data embedding is used, a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute must be specified,
-and must correspond with the media (content) type of the data resource. In these cases, if there is no defined type, the type <code>application/octet-stream</code>
-should be used. In the case of sourced data embedding, the media (content) type of the resolved <a href="#embedded-content-vocabulary-source">source</a> element
-is used as the type.</p><p>If a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute is not specified or resolved or is specified as a generic type,
-such as <code>application/octet-stream</code>, and additional format information is known about a referenced data resource,
-then a <a href="#embedded-content-attribute-format">format</a> attribute should be specified as a hint to the content processor.</p><p>The use of simple data embedding is illustrated by the following examples.</p><a id="embedded-content-vocabulary-data-example-1"></a><table class="example"><caption>Example Fragment – Simple Data Embedding in Data Defining Context</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;head&gt;
-  &lt;resources&gt;
-    &lt;data xml:id="sharedImageData" type="image/png" length="119"&gt;
-      iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-      YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-    &lt;/data&gt;
-    &lt;image xml:id="sharedImage"&gt;
-      &lt;source src="#sharedImageData"/&gt;
-    &lt;/image&gt;
-  &lt;/resources&gt;
-&lt;/head&gt;
-...
-&lt;body xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;div tts:backgroundImage="#sharedImage"/&gt;
-  &lt;div tts:backgroundImage="#sharedImage"/&gt;
-&lt;/body&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="embedded-content-vocabulary-data-example-2"></a><table class="example"><caption>Example Fragment – Simple Data Embedding in Data Binding Context for Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;div&gt;
-  &lt;metadata xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-    &lt;ttm:desc&gt;caption with metadata containing tunneled CEA-608 data&lt;/ttm:desc&gt;
-    &lt;data format="http://www.smpte-ra.org/schemas/2052-1/2013/smpte-tt#cea608"&gt;
-      gIAVLJQsnSAcIJ0sHCyAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICA
-      gICAgICAgICAgICAgICAgIAVIJQgE/QT9Jehl6FU5VTlc/Rz9CBDIENhcGFw9On06e9u725zgHOA
-      lNCU0Jehl6HEVMRU1iDWIMHjwePj5ePlc3NzcyDQINDy7/Lv6uXq5eP04/QsICwgV8dXx8LIwsit
-      zq3OQ8FDwc2AzYCUcJRwlyOXI6jyqPJ1bnVubulu6W5nbmcg9CD06W3pbeW65bogNCA0IG0gbelu
-      6W6uIK4gMbUxtSBzIHPl4+XjrimuKRUslCwVL5QvgIA=
-    &lt;/data&gt;
-  &lt;/metadata&gt;
-  &lt;p&gt;Test Captions&lt;br/&gt;DTV Access Project, WGHB-NCAM&lt;br/&gt;(running time: 4min. 15sec.)&lt;/p&gt;
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="embedded-content-vocabulary-data-example-3"></a><table class="example"><caption>Example Fragment – Simple Data Embedding in Data Binding Context for Source</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;div&gt;
-  &lt;image&gt;
-    &lt;source&gt;
-      &lt;data type="image/png" length="119"&gt;
-        iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-        YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-      &lt;/data&gt;
-    &lt;/source&gt;
-  &lt;/image&gt;
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p></p></div><div class="div3">
-<h4><a id="embedded-content-vocabulary-font"></a>9.1.4 font</h4><p>The <code>font</code> element is used to define an author supplied <a href="#terms-font-resource">font resource</a>.</p><p>A <code>font</code> element may appear as a child of a <a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element, referred to as a
-<a href="#terms-font-defining-context">font defining context</a>.</p><p>The <code>font</code> element accepts as its children
-zero or more elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group followed by zero or more
-<a href="#embedded-content-vocabulary-source"><code>source</code></a> elements.</p><a id="elt-syntax-font"></a><table class="syntax"><caption>XML Representation – Element Information Item: font</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;font
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  family = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#embedded-content-attribute-format">format</a> = <a href="#embedded-content-value-font-format">&lt;font-format&gt;</a>
-  range = <a href="#embedded-content-value-unicode-range">&lt;unicode-range&gt;</a>
-  style = (normal|italic|oblique)
-  <a href="#embedded-content-attribute-src">src</a> = <a href="#embedded-content-value-font">&lt;font&gt;</a>
-  <a href="#embedded-content-attribute-type">type</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  weight = (normal|bold)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#embedded-content-vocabulary-source">source</a>*
-&lt;/font&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>font</code> element defines a <a href="#terms-font-resource">font resource</a> either (1) by referring to an <a href="#terms-external-data-resource">external data resource</a>
-or (2) defining or referring to an <a href="#terms-embedded-data-resource">embedded data resource</a>, where the <a href="#terms-data-resource">data resource</a>
-contains font content.</p><p>If a <code>font</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must not specify a
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element. Conversely,
-if a <code>font</code> element does not specify a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must specify one or more
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> elements.</p><p>If a <code>font</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute and its value does not refer to a fragment of the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a>, then it should specify a
-a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute, in which case the value of the
-<a href="#embedded-content-attribute-type"><code>type</code></a> attribute must correspond with the media (content) type
-of the referenced resource. Otherwise, a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute must not be specified.</p><p>If a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute is not specified or is specified as a generic type, such as <code>application/octet-stream</code>,
-and additional format information is known about a referenced <a href="#terms-font-resource">font resource</a>, then a <a href="#embedded-content-attribute-format"><code>format</code></a> attribute should be specified as a hint to the
-content processor.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A font format hint might be useful to a content processor to avoid accessing a <a href="#terms-font-resource">font resource</a> it knows it cannot decode.</p></div><p>If a <code>font</code> element includes a child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element, then
-the <a href="#embedded-content-attribute-format"><code>format</code></a> attribute of the <code>source</code> child, if specified, must adhere to the <a href="#embedded-content-value-font-format">&lt;font-format&gt;</a>
-value expression.</p><p>If any of the <code>family</code>, <code>range</code>, <code>style</code>, or <code>weight</code> attributes are specified, then
-they override the family name, supported character ranges, style, and weight of the actual <a href="#terms-font-resource">font resource</a>. In particular,
-if the specified attribute value(s) differ from the value(s) of these font characteristics as encoded in the <a href="#terms-font-resource">font resource</a>, then
-the specified attribute value(s) are to be used instead of the font characteristics encoded in the <a href="#terms-font-resource">font resource</a>.</p><p>If any of the <code>family</code>, <code>range</code>, <code>style</code>, or <code>weight</code> attributes are not specified, then their values
-must be considered to be equal to the value(s) of the same named font characteristics encoded in the <a href="#terms-font-resource">font resource</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Authors are advised to use subset fonts wherever possible. A subset font is a syntactically valid <a href="#terms-font-resource">font resource</a> that
-removes unreferenced glyphs and unreferenced glyph metrics. In general, a subset font is tied to a specific document, since it may have been generated
-based on the actual character content of that document.</p></div><table border="1" class="ednote" summary="Editorial note: Font Loading Semantics"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Font Loading Semantics</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Specify font loading semantics, making as much use as possible (by reference) of material found at
-<a href="http://dev.w3.org/csswg/css-fonts/#font-face-loading">CSS Font Module Level 3, Font Loading Guidelines</a>.</td></tr></table><p>The use of the <code>font</code> element is illustrated by the following example.</p><a id="embedded-content-vocabulary-font-example-1"></a><table class="example"><caption>Example Fragment – Font</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;head&gt;
-  &lt;resources&gt;
-    &lt;data xml:id="lastResortFont" type="application/font-woff"&gt;
-      ... <em>base64 encoded data</em> ...
-    &lt;/data&gt;
-    &lt;font family="MyFont" range="u+20-7f,u+90-9f"&gt;
-      &lt;source src="http://example.com/fonts/myfont.otf" format="opentype"/&gt;
-      &lt;source src="#lastResortFont"/&gt;
-    &lt;/font&gt;
-  &lt;/resources&gt;
-&lt;/head&gt;
-...
-&lt;p tts:fontFamily="MyFont"&gt;use my font or last resort font&lt;/p&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p></div><div class="div3">
-<h4><a id="embedded-content-vocabulary-image"></a>9.1.5 image</h4><p>The <code>image</code> element is used to define an author supplied <a href="#terms-image-resource">image resource</a>.</p><p>An <code>image</code> element may appear in two contexts: (1) as a child of a <a href="#embedded-content-vocabulary-resource"><code>resource</code></a> element and
-(2) as a child of an element in the <a href="#element-vocab-group-block">Block.class</a> element group, namely, as a child of a
-<a href="#content-vocabulary-div"><code>div</code></a> or <a href="#content-vocabulary-p"><code>p</code></a> element, or
-as a child of a <a href="#content-vocabulary-span"><code>span</code></a> element. The former is referred to as an
-<a href="#terms-image-defining-context">image defining context</a>, the latter as an <a href="#terms-image-presentation-context">image presentation context</a>.</p><p>When an <code>image</code> element appears in an <a href="#terms-image-defining-context">image defining context</a>, it
-serves as a sharable definition of an <a href="#terms-image-resource">image resource</a> that may be referenced by another <code>image</code> element or by
-a <a href="#style-attribute-backgroundImage"><code>tts:backgroundImage</code></a> style attribute
-in the <a href="#terms-enclosing-document-instance">enclosing document instance</a>. In this case, the active time interval of the <code>image</code> element
-is the same as the active time interval of its parent <a href="#embedded-content-vocabulary-resource"><code>resource</code></a> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A sharable definition of an <a href="#terms-image-resource">image resource</a> specifies an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute in order to be referenced
-by an <code>image</code> element or by a <a href="#style-attribute-backgroundImage"><code>tts:backgroundImage</code></a> style attribute
-in an <a href="#terms-image-presentation-context">image presentation context</a>.</p></div><p>When an <code>image</code> element appears in an <a href="#terms-image-presentation-context">image presentation context</a>, it
-serves as a non-sharable definition of an <a href="#terms-image-resource">image resource</a> that implies presentation (rendering) semantics.
-In this case, the active time interval of the <code>image</code> element is the same as the active time interval of its parent
-<a href="#terms-content-element">content element</a>.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A non-sharable definition of an <a href="#terms-image-resource">image resource</a> may or may not specify an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute, but this
-identifier is not referenced by other <code>image</code> elements, or, if it is, the reference is ignored.</p></div><p>When an <code>image</code> element appears as a child of a <a href="#contentt-vocabulary-div"><code>div</code></a> element, then its presentation
-produces a block area in which the image is rendered; i.e., a block boundary is implied before and after the <code>image</code> element. In contrast,
-when an <code>image</code> element appears as a child of a <a href="#contentt-vocabulary-p"><code>p</code></a> or <a href="#contentt-vocabulary-span"><code>span</code></a>
-element, then its presentation produces an inline area in which the image is rendered; i.e., no block boundary is implied before and after the <code>image</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In <a href="#css2">[CSS2]</a>, these semantics would correspond to an <code>image</code> element being associated with a <code>display</code> style property with a
-value of <code>block</code> or <code>inline</code>, respectively.</p></div><p>The presentation of an <a href="#terms-image-resource">image resource</a> referenced by a
-<a href="#style-attribute-backgroundImage"><code>tts:backgroundImage</code></a> style attribute must not affect content layout.</p><p>The <code>image</code> element accepts as its children
-zero or more elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group followed by zero or more
-<a href="#embedded-content-vocabulary-source"><code>source</code></a> elements.</p><a id="elt-syntax-image"></a><table class="syntax"><caption>XML Representation – Element Information Item: image</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;image
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#embedded-content-attribute-format">format</a> = <a href="#embedded-content-value-image-format">&lt;image-format&gt;</a>
-  <a href="#embedded-content-attribute-src">src</a> = <a href="#embedded-content-value-image">&lt;image&gt;</a>
-  <a href="#embedded-content-attribute-type">type</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xlink-arcrole">xlink:arcrole</a> = <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>+
-  <a href="#content-attribute-xlink-href">xlink:href</a> = <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-  <a href="#content-attribute-xlink-role">xlink:role</a> = <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>+
-  <a href="#content-attribute-xlink-show">xlink:show</a> = (<em>new</em>|<em>replace</em>|<em>embed</em>|<em>other</em>|<em>none</em>) : new
-  <a href="#content-attribute-xlink-title">xlink:title</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#embedded-content-vocabulary-source">source</a>*
-&lt;/image&gt;
-</pre></div>
-</td></tr></tbody></table><p>An <code>image</code> element defines an <a href="#terms-image-resource">image resource</a> either (1) by referring to an <a href="#terms-external-data-resource">external data resource</a>
-or (2) defining or referring to an <a href="#terms-embedded-data-resource">embedded data resource</a>, where the <a href="#terms-data-resource">data resource</a>
-contains image content.</p><p>If an <code>image</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must not specify a
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element. Conversely,
-if an <code>image</code> element does not specify a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must specify one or more
-child <a href="#embedded-content-vocabulary-source"><code>source</code></a> elements.</p><p>If an <code>image</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute and its value does not refer to a fragment of the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a>, then it should specify a
-a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute, in which case the value of the
-<a href="#embedded-content-attribute-type"><code>type</code></a> attribute must correspond with the media (content) type
-of the referenced resource. Otherwise, a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute must not be specified.</p><p>If a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute is not specified or is specified as a generic type, such as <code>application/octet-stream</code>,
-and additional format information is known about a referenced <a href="#terms-image-resource">image resource</a>, then a <a href="#embedded-content-attribute-format"><code>format</code></a> attribute should be specified as a hint to the
-content processor.</p><p>If an <code>image</code> element includes a child <a href="#embedded-content-vocabulary-source"><code>source</code></a> element, then
-the <a href="#embedded-content-attribute-format"><code>format</code></a> attribute of the <code>source</code> child, if specified, must adhere to the <a href="#embedded-content-value-image-format">&lt;image-format&gt;</a>
-value expression.</p><p>An <code>image</code> element may specify either (both)
-<a href="#style-attribute-width"><code>tts:width</code></a> or (and) 
-<a href="#style-attribute-height"><code>tts:height</code></a> style attributes in order to specify the presentation width or height of the image when
-intrinsic width or height information is not available or is intended to be overridden. If (either or both of) these attributes are specified on both an
-<code>image</code> element in an <a href="#terms-image-presentation-context">image presentation context</a> and on the
-<code>image</code> element in an <a href="#terms-image-defining-context">image defining context</a> to which the former refers, then
-these attributes specified on the former take precedence over those specified on the latter.</p><p>The linking attributes <code>xlink:*</code> may be used to link an <code>image</code> element with related content, using the
-specified location (<code>href</code>), roles, and title. The behavior of link activation is affected by the <code>xlink:show</code> attribute,
-the precise meaning of which is determined by the <a href="#terms-document-processing-context">document processing context</a>.</p><p>The use of the <code>image</code> element is illustrated by the following examples.</p><a id="embedded-content-vocabulary-image-example-1"></a><table class="example"><caption>Example Fragment – External Image Resources</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;div&gt;
-  &lt;p&gt;This division has a content image that appears as a block area after this paragraph.&lt;/p&gt;
-  &lt;image src="http://example.com/images/caption.png" type="image/png"/&gt;
-&lt;div&gt;
-...
-&lt;div tts:backgroundImage="http://example.com/images/background.png"&gt;
-  &lt;p&gt;This division has a background image that appears under this paragraph.&lt;/p&gt;
-&lt;div&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p><a id="embedded-content-vocabulary-image-example-2"></a><table class="example"><caption>Example Fragment – Sharable Embedded Image Resource</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;head&gt;
-  &lt;resources&gt;
-    &lt;data xml:id="caption" type="image/png" length="119"&gt;
-      iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-      YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-    &lt;/data&gt;
-  &lt;/resources&gt;
-&lt;/head&gt;
-&lt;body&gt;
-  &lt;div&gt;
-    &lt;p&gt;
-      &lt;image&gt;
-        &lt;source src="#caption"/&gt;
-      &lt;/image&gt;
-    &lt;p&gt;
-    ...
-    &lt;p&gt;
-      &lt;image&gt;
-        &lt;source src="#caption"/&gt;
-      &lt;/image&gt;
-    &lt;p&gt;
-  &lt;/div&gt;
-&lt;/body&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="embedded-content-vocabulary-image-example-3"></a><table class="example"><caption>Example Fragment – External Image Resource with Non-Sharable Image Fallback</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;div&gt;
-  &lt;image&gt;
-    &lt;source src="http://example.com/images/caption.png" type="image/png"/&gt;
-    &lt;source&gt;
-      &lt;data type="image/png" length="119"&gt;
-        iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-        YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-      &lt;/data&gt;
-    &lt;/source&gt;
-  &lt;/image&gt;
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p></p></div><div class="div3">
-<h4><a id="embedded-content-vocabulary-resources"></a>9.1.6 resources</h4><p>The <code>resources</code> element is a container element used to group
-definitions of embedded content, including metadata that applies to this embedded content.</p><p>The <code>resources</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more elements in the
-<a href="#element-vocab-group-data"><code>Data.class</code></a>,
-<a href="#element-vocab-group-data"><code>Embedded.class</code></a>, or
-<a href="#element-vocab-group-data"><code>Font.class</code></a> element groups.</p><a id="elt-syntax-resources"></a><table class="syntax"><caption>XML Representation – Element Information Item: resources</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;resources
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, (<a href="#element-vocab-group-data">Data.class</a>|<a href="#element-vocab-group-embedded">Embedded.class</a>|<a href="#element-vocab-group-font">Font.class</a>)*
-&lt;/resources&gt;
-</pre></div>
-</td></tr></tbody></table><p>To the extent that time semantics apply to the content of the
-<code>resources</code> element, the implied time interval of this element is
-defined to be coterminous with the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p></div><div class="div3">
-<h4><a id="embedded-content-vocabulary-source"></a>9.1.7 source</h4><p>The <code>source</code> element is used to specify the source of an <a href="#terms-embedded-content-resource">embedded content resource</a>.</p><p>The <code>source</code> element accepts as its children
-zero or more elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group followed by zero or one
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element.</p><p>If a <code>source</code> element specifies a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must not specify a
-child <a href="#embedded-content-vocabulary-data"><code>data</code></a> element, in which case it is referred to as
-an <a href="#terms-external-source">external source</a> if the <a href="#embedded-content-attribute-src"><code>src</code></a> attribute refers to an external resource, or
-a <a href="#terms-non-nested-embedded-source">non-nested embedded source</a>
-if the <a href="#embedded-content-attribute-src"><code>src</code></a> attribute refers to an embedded resource
-in the <a href="#terms-enclosing-document-instance">enclosing document instance</a>.</p><p>If a <code>source</code> element does not specify a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute, then it must specify a
-child <a href="#embedded-content-vocabulary-data"><code>data</code></a> element, in which case it is referred to as
-a <a href="#terms-nested-embedded-source">nested embedded source</a>.</p><p>A <code>source</code> element must not have an ancestor <code>source</code> element.</p><a id="elt-syntax-source"></a><table class="syntax"><caption>XML Representation – Element Information Item: source</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;source
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#embedded-content-attribute-format">format</a> = <a href="#embedded-content-value-data-format">&lt;data-format&gt;</a>
-  <a href="#embedded-content-attribute-src">src</a> = <a href="#embedded-content-value-data">&lt;data&gt;</a>
-  <a href="#embedded-content-attribute-type">type</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#embedded-content-vocabulary-data">data</a>?
-&lt;/source&gt;
-</pre></div>
-</td></tr></tbody></table><p>If a <a href="#embedded-content-attribute-format"><code>format</code></a> attribute is specified, then it provides additional hint information about the format (i.e., formal syntax) of the
-embedded content. Such information may be useful in cases where no standard media (content) type label has been defined. Depending on the
-context of use of a <code>source</code> element, the values of this attribute may be further constrained.</p><p>If a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute is specified and its value refers to a fragment of the <a href="#terms-enclosing-document-instance">enclosing document instance</a>,
-then there must be a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element child of a <a href="#document-structure-vocabulary-resources"><code>resources</code></a>
-element which is identified by that fragment, i.e., has an <code>xml:id</code> attribute the value of which matches the fragment identifier.</p><p>If a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute is specified and its value does not refer to a fragment of the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a>, then
-a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute should be specified, in which case it must correspond with the media (content) type
-of the referenced resource.</p><p>If a <a href="#embedded-content-attribute-src"><code>src</code></a> attribute is specified and its value does refer to a fragment of the
-<a href="#terms-enclosing-document-instance">enclosing document instance</a>, then
-a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute must not be specified; rather, the content type of the embedded resource is determined by
-the value of the <a href="#embedded-content-attribute-type"><code>type</code></a> attribute on the referenced or embedded
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element.</p><p>The use of the <code>source</code> element is illustrated by the following examples.</p><a id="embedded-content-vocabulary-source-example-1"></a><table class="example"><caption>Example Fragment – External Source</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;image&gt;
-  &lt;source src="http://example.com/images/caption.png" type="image/png"/&gt;
-&lt;/image&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p><a id="embedded-content-vocabulary-source-example-2"></a><table class="example"><caption>Example Fragment – Non-Nested Embedded Source</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;data xml:id="caption" type="image/png" length="119"&gt;
-  iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-  YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-&lt;/data&gt;
-...
-&lt;image&gt;
-  &lt;source src="#caption"/&gt;
-&lt;/image&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p><a id="embedded-content-vocabulary-source-example-3"></a><table class="example"><caption>Example Fragment – Nested Embedded Source</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;image&gt;
-  &lt;source&gt;
-    &lt;data type="image/png" length="119"&gt;
-      iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-      YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-    &lt;/data&gt;
-  &lt;/source&gt;
-&lt;/image&gt;
-...
-</pre></div>
-</td></tr></tbody></table></div></div><div class="div2">
-<h3><a id="embedded-content-attribute-vocabulary"></a>9.2 Embedded Content Attribute Vocabulary</h3><p>This section defines the following attributes for use with certain <a href="#terms-embedded-content-element">embedded content elements</a>
-and <a href="#terms-embedded-data-element">data elements</a>:</p><ul><li><p><a href="#embedded-content-attribute-encoding"><b>9.2.1 encoding</b></a></p></li><li><p><a href="#embedded-content-attribute-format"><b>9.2.2 format</b></a></p></li><li><p><a href="#embedded-content-attribute-src"><b>9.2.3 src</b></a></p></li><li><p><a href="#embedded-content-attribute-type"><b>9.2.4 type</b></a></p></li></ul><div class="div3">
-<h4><a id="embedded-content-attribute-encoding"></a>9.2.1 encoding</h4><p>The <code>encoding</code> attribute is used to specify the encoding format of data.</p><p>The <code>encoding</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#embedded-content-vocabulary-chunk"><code>chunk</code></a></p></li><li><p><a href="#embedded-content-vocabulary-data"><code>data</code></a></p></li></ul><p>If specified, the value of an <code>encoding</code> attribute must take one of the following values as defined by
-<a href="#data-encodings">[Data Encodings]</a>:</p><ul><li><p><code>base16</code></p></li><li><p><code>base32</code></p></li><li><p><code>base32hex</code></p></li><li><p><code>base64</code></p></li><li><p><code>base64url</code></p></li></ul><p>If not specified, then <code>base64</code> semantics apply.</p></div><div class="div3">
-<h4><a id="embedded-content-attribute-format"></a>9.2.2 format</h4><p>The <code>format</code> attribute is used to specify hints about the media (content) format of
-an embedded content resource beyond media (content) type information
-provided by a <a href="#embedded-content-attribute-type"><code>type</code></a> attribute.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <code>format</code> attribute is useful in the absence of a registered media (content) type,
-e.g., when no media (content) type is available or a generic type is used, such as
-<code>application/octet-stream</code>.</p></div><p>The <code>format</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#embedded-content-vocabulary-audio"><code>audio</code></a></p></li><li><p><a href="#embedded-content-vocabulary-data"><code>data</code></a></p></li><li><p><a href="#embedded-content-vocabulary-font"><code>font</code></a></p></li><li><p><a href="#embedded-content-vocabulary-image"><code>image</code></a></p></li><li><p><a href="#embedded-content-vocabulary-source"><code>source</code></a></p></li></ul><p>The value of a <code>format</code> attribute must adhere to a
-<a href="#embedded-content-value-data-format">&lt;data-format&gt;</a> expression.</p><p>Depending on the context of use, additional constraints may apply.</p></div><div class="div3">
-<h4><a id="embedded-content-attribute-src"></a>9.2.3 src</h4><p>The <code>src</code> attribute is used to specify the location or an identifier that maps to the location of data resource.</p><p>The <code>src</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#embedded-content-vocabulary-audio"><code>audio</code></a></p></li><li><p><a href="#embedded-content-vocabulary-data"><code>data</code></a></p></li><li><p><a href="#embedded-content-vocabulary-font"><code>font</code></a></p></li><li><p><a href="#embedded-content-vocabulary-image"><code>image</code></a></p></li><li><p><a href="#embedded-content-vocabulary-source"><code>source</code></a></p></li></ul><p>If specified, the value of a <code>src</code> attribute must adhere to the value syntax of the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>, §3.2.17.</p><p>Depending on the context of use, additional constraints may apply.</p></div><div class="div3">
-<h4><a id="embedded-content-attribute-type"></a>9.2.4 type</h4><p>The <code>type</code> attribute is used to specify the media (content) type of data resource, and may express additional
-parameters that characterize the data.</p><p>The <code>type</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#embedded-content-vocabulary-audio"><code>audio</code></a></p></li><li><p><a href="#embedded-content-vocabulary-data"><code>data</code></a></p></li><li><p><a href="#embedded-content-vocabulary-font"><code>font</code></a></p></li><li><p><a href="#embedded-content-vocabulary-image"><code>image</code></a></p></li></ul><p>If specified, the value of a <code>type</code> attribute must adhere to the value syntax of the <code>Content-Type</code>
-MIME header defined by <a href="#mime">[MIME]</a>, §5.1.</p><p>If not specified, then the media (content) type is unknown or deliberately unspecified.</p><p>When decoding a data resource for which a <code>type</code> attribute is specified, then content processing
-must respect the specified type whether it is correct or not. That is, if a <code>type</code> attribute mis-specifies the
-type of a data resource, then content processing must not attempt to override that type by performing content
-sniffing.</p></div></div><div class="div2">
-<h3><a id="embedded-content-value-expressions"></a>9.3 Embedded Content Value Expressions</h3><p>Embedded content elements as well as certain style property values make use of the following expressions:</p><ul><li><p><a href="#embedded-content-value-audio"><b>9.3.1 &lt;audio&gt;</b></a></p></li><li><p><a href="#embedded-content-value-audio-format"><b>9.3.2 &lt;audio-format&gt;</b></a></p></li><li><p><a href="#embedded-content-value-data"><b>9.3.3 &lt;data&gt;</b></a></p></li><li><p><a href="#embedded-content-value-data-format"><b>9.3.4 &lt;data-format&gt;</b></a></p></li><li><p><a href="#embedded-content-value-font"><b>9.3.5 &lt;font&gt;</b></a></p></li><li><p><a href="#embedded-content-value-font-format"><b>9.3.6 &lt;font-format&gt;</b></a></p></li><li><p><a href="#embedded-content-value-image"><b>9.3.7 &lt;image&gt;</b></a></p></li><li><p><a href="#embedded-content-value-image-format"><b>9.3.8 &lt;image-format&gt;</b></a></p></li><li><p><a href="#embedded-content-value-unicode-range"><b>9.3.9 &lt;unicode-range&gt;</b></a></p></li></ul><p>In the syntax representations defined in this section, no
-linear whitespace (LWSP) is implied or permitted between tokens
-unless explicitly specified.</p><div class="div3">
-<h4><a id="embedded-content-value-audio"></a>9.3.1 &lt;audio&gt;</h4><p>An &lt;audio&gt; value expression is used to specify an <a href="#terms-audio-resource">audio resource</a> by reference.</p><a id="audio-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;audio&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;audio&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If an &lt;audio&gt; value expression takes the form of a <a href="#terms-fragment-identifier">fragment identifier</a>,
-then that fragment identifier must reference an <a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element that is a child of a
-<a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element in the <a href="#terms-enclosing-document-instance">enclosing document instance</a>.</p></div><div class="div3">
-<h4><a id="embedded-content-value-audio-format"></a>9.3.2 &lt;audio-format&gt;</h4><p>An &lt;audio-format&gt; expression is used to specify the format of a <a href="#terms-audio-resource">audio resource</a>. Additional format information is useful in the case
-of <a href="#terms-audio-resource">audio resources</a> that lack a registered media (content) type.</p><a id="audio-format-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;audio-format&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;audio-format&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-  | <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If a format expression takes the form of an <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>,
-then it must express an absolute URI.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not standardize the set of format tokens for use with audio content. Authors are encouraged to
-use tokens in common use, or absent that, to add a prefix <code>"x-"</code> to form a private use token.</p></div></div><div class="div3">
-<h4><a id="embedded-content-value-data"></a>9.3.3 &lt;data&gt;</h4><p>A &lt;data&gt; value expression is used to specify a data resource by reference.</p><a id="data-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;data&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;data&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If a &lt;data&gt; value expression takes the form of a <a href="#terms-fragment-identifier">fragment identifier</a>,
-then that fragment identifier must reference an <a href="#embedded-content-vocabulary-data"><code>data</code></a> element that is a child of a
-<a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element in the <a href="#terms-enclosing-document-instance">enclosing document instance</a>.</p></div><div class="div3">
-<h4><a id="embedded-content-value-data-format"></a>9.3.4 &lt;data-format&gt;</h4><p>A &lt;data-format&gt; expression is used to specify the format of a data resource. Additional format information is useful in the case
-of data resources that lack a registered media (content) type.</p><a id="data-format-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;data-format&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;data-format&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-  | <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If a format expression takes the form of an <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>,
-then it must express an absolute URI.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not standardize the set of format tokens for use with data content. Authors are encouraged to
-use tokens in common use, or absent that, to add a prefix <code>"x-"</code> to form a private use token.</p></div></div><div class="div3">
-<h4><a id="embedded-content-value-font"></a>9.3.5 &lt;font&gt;</h4><p>An &lt;font&gt; expression is used to specify a <a href="#terms-font-resource">font resource</a> by reference.</p><a id="font-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;font&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;font&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If a &lt;font&gt; expression takes the form of a <a href="#terms-fragment-identifier">fragment identifier</a>,
-then that fragment identifier must reference a <a href="#embedded-content-vocabulary-font"><code>font</code></a> element that is a child of a
-<a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element in the <a href="#terms-enclosing-document-instance">enclosing document instance</a>.</p></div><div class="div3">
-<h4><a id="embedded-content-value-font-format"></a>9.3.6 &lt;font-format&gt;</h4><p>A &lt;font-format&gt; expression is used to specify the format of a <a href="#terms-font-resource">font resource</a>. Additional format information is useful in the case
-of <a href="#terms-font-resource">font resources</a> due that lack a registered media (content) type.</p><a id="font-format-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;font-format&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;font-format&gt;
-  : eot                                     // embedded opentype
-  | otf                                     // opentype
-  | ttf                                     // truetype
-  | woff                                    // web open font format
-  | <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-  | <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If a format expression takes the form of an <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>,
-then it must express an absolute URI.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification standardizes a limited set of format tokens for use with font content. In case none of
-these tokens are appropriate, authors are encouraged to use tokens in common use, or absent that, to add a
-prefix <code>"x-"</code> to form a private use token.</p></div></div><div class="div3">
-<h4><a id="embedded-content-value-image"></a>9.3.7 &lt;image&gt;</h4><p>An &lt;image&gt; expression is used to specify an <a href="#terms-image-resource">image resource</a> by reference.</p><a id="image-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;image&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;image&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If an &lt;image&gt; expression takes the form of a <a href="#terms-fragment-identifier">fragment identifier</a>,
-then that fragment identifier must reference an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element that is a child of a
-<a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element in the <a href="#terms-enclosing-document-instance">enclosing document instance</a>.</p></div><div class="div3">
-<h4><a id="embedded-content-value-image-format"></a>9.3.8 &lt;image-format&gt;</h4><p>An &lt;image-format&gt; expression is used to specify the format of a <a href="#terms-image-resource">image resource</a>. Additional format information is useful in the case
-of <a href="#terms-image-resource">image resources</a> that lack a registered media (content) type.</p><a id="image-format-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;image-format&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;image-format&gt;
-  : <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-  | <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>
-</pre></div>
-</td></tr></tbody></table><p>If a format expression takes the form of a <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>,
-then it must express an absolute URI.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not standardize the set of format tokens for use with image content. Authors are encouraged to
-use tokens in common use, or absent that, to add a prefix <code>"x-"</code> to form a private use token.</p></div></div><div class="div3">
-<h4><a id="embedded-content-value-unicode-range"></a>9.3.9 &lt;unicode-range&gt;</h4><p>A &lt;unicode-range&gt; expression is used to specify a collection of Unicode codepoints by enumerating singleton codepoints or ranges of codepoints.</p><a id="unicode-range-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;unicode-range&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;unicode-range&gt;
-  : range ("," range)*
-
-range
-  : codepoint
-  | codepoint "-" codepoint
-
-codepoint
-  : ("U"|"u") "+" hexdigit-or-wildcard{1,6}
-
-hexdigit-or-wildcard
-  : <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a>
-  | "?"
-</pre></div>
-</td></tr></tbody></table><p>No LWSP is permitted within a <code>codepoint</code> sub-expression.</p></div></div></div><div class="div1">
-<h2><a id="styling"></a>10 Styling</h2><p>This section specifies the <em>styling</em> matter of the core
-vocabulary catalog, where
-styling is to be understood as a separable layer of information that applies to
-content and that denotes authorial intentions about the presentation of
-that content.</p><p>Styling attributes are included in TTML to enable authorial intent of presentation
-to be included within a self-contained document. This section describes
-the semantics of style presentation in terms of a standard processing
-model. TTML Processors are not required to present <a href="#terms-document-instance">document instances</a> in any particular way; 
-but an implementation of this model by a TTML <a href="#terms-presentation-processor">presentation processor</a>
-that provides externally observable results that are consistent with this model is
-likely to lead to a user experience that closely resembles the experience intended by
-the documents' authors.</p><p>The semantics of TTML style presentation are described in terms of the model 
-in <a href="#xsl11">[XSL 1.1]</a>. The effects of the attributes in this section 
-are intended to be compatible with the layout and formatting model of XSL; however, Presentation agents
-may use any technology to satisfy the authorial intent of the document. In particular 
-since <a href="#css2">[CSS2]</a> is a subset of this model, a CSS processor may be used 
-for the features that the models have in common.</p><p>No normative use of an
-<code>&lt;?xml-stylesheet ... ?&gt;</code> processing instruction is defined
-by this specification.</p><div class="div2">
-<h3><a id="styling-element-vocabulary"></a>10.1 Styling Element Vocabulary</h3><p>The following elements specify the structure and principal styling aspects of a
-<a href="#terms-document-instance">document instance</a>:</p><ul><li><p><a href="#styling-vocabulary-initial"><b>10.1.1 initial</b></a></p></li><li><p><a href="#styling-vocabulary-style"><b>10.1.2 style</b></a></p></li><li><p><a href="#styling-vocabulary-styling"><b>10.1.3 styling</b></a></p></li></ul><div class="div3">
-<h4><a id="styling-vocabulary-initial"></a>10.1.1 initial</h4><p>The <code>initial</code> element is used to modify the initial value of one or more style properties, i.e, to specify use of different value(s) than
-the specification defined initial value(s).</p><p>The <code>initial</code> element accepts as its children zero or more <code>metadata</code> elements.</p><a id="elt-syntax-initial"></a><table class="syntax"><caption>XML Representation – Element Information Item: initial</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;initial
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*
-&lt;/initial&gt;
-</pre></div>
-</td></tr></tbody></table><p>The <code>initial</code> element is illustrated by the following example, wherein
-the initial value of the <code>tts:color</code> property is defined to be <code>yellow</code>.</p><a id="style-vocabulary-initial-example-1"></a><table class="example"><caption>Example Fragment – <code>initial</code></caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;head&gt;
-  &lt;styling&gt;
-    <span class="strong">&lt;initial tts:color="yellow"/&gt;</span>
-  &lt;styling&gt;
-&lt;head&gt;
-...
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="styling-vocabulary-style"></a>10.1.2 style</h4><p>The <code>style</code> element is used to define
-a set of style specifications expressed as a
-specified style set in accordance with
-<a href="#semantics-style-resolution-processing-sss"><b>10.4.4.2 Specified Style Set Processing</b></a>.</p><p>The <code>style</code> element accepts as its children zero or more <code>metadata</code> elements.</p><a id="elt-syntax-style"></a><table class="syntax"><caption>XML Representation – Element Information Item: style</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;style
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*
-&lt;/style&gt;
-</pre></div>
-</td></tr></tbody></table><p>If a <code>style</code> element appears as a descendant of a
-<code>region</code> element, then the <code>style</code> element must be
-ignored for the purpose of computing referential styles as defined by
-<a href="#semantics-style-association-referential"><b>10.4.1.2 Referential Styling</b></a> and <a href="#semantics-style-association-chained-referential"><b>10.4.1.3 Chained Referential Styling</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>That is to say, when referential styling is used by an element to
-refer to a <code>style</code> element, then the referenced <code>style</code>
-element must appear as a descendant of the <code>styling</code> element, and
-not in any other context.</p></div></div><div class="div3">
-<h4><a id="styling-vocabulary-styling"></a>10.1.3 styling</h4><p>The <code>styling</code> element is a container element used to group
-styling matter, including metadata that applies to styling matter.</p><p>The <code>styling</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more <code>initial</code> elements,
-followed by zero or more <code>style</code> elements.</p><a id="elt-syntax-styling"></a><table class="syntax"><caption>XML Representation – Element Information Item: styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;styling
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#styling-vocabulary-initial">initial</a>*, <a href="#styling-vocabulary-style">style</a>*
-&lt;/styling&gt;
-</pre></div>
-</td></tr></tbody></table><p>To the extent that time semantics apply to the content of the
-<code>styling</code> element, the implied time interval of this element is
-defined to be coterminous with the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p></div></div><div class="div2">
-<h3><a id="styling-attribute-vocabulary"></a>10.2 Styling Attribute Vocabulary</h3><p>This section defines the <a href="#style-attribute-style"><b>10.2.1 style</b></a> attribute used
-with certain animation elements, <a href="#terms-content-element">content elements</a>, certain layout elements, and style definition elements.</p><p>In addition, this section specifies the following attributes in the TT Style Namespace
-for use with style definition elements, certain layout elements, and <a href="#terms-content-element">content elements</a>
-that support inline style specifications:</p><ul><li><p><a href="#style-attribute-backgroundColor"><b>10.2.2 tts:backgroundColor</b></a></p></li><li><p><a href="#style-attribute-backgroundImage"><b>10.2.3 tts:backgroundImage</b></a></p></li><li><p><a href="#style-attribute-backgroundPosition"><b>10.2.4 tts:backgroundPosition</b></a></p></li><li><p><a href="#style-attribute-backgroundRepeat"><b>10.2.5 tts:backgroundRepeat</b></a></p></li><li><p><a href="#style-attribute-border"><b>10.2.6 tts:border</b></a></p></li><li><p><a href="#style-attribute-color"><b>10.2.7 tts:color</b></a></p></li><li><p><a href="#style-attribute-direction"><b>10.2.8 tts:direction</b></a></p></li><li><p><a href="#style-attribute-display"><b>10.2.9 tts:display</b></a></p></li><li><p><a href="#style-attribute-displayAlign"><b>10.2.10 tts:displayAlign</b></a></p></li><li><p><a href="#style-attribute-extent"><b>10.2.11 tts:extent</b></a></p></li><li><p><a href="#style-attribute-fontFamily"><b>10.2.12 tts:fontFamily</b></a></p></li><li><p><a href="#style-attribute-fontKerning"><b>10.2.13 tts:fontKerning</b></a></p></li><li><p><a href="#style-attribute-fontShear"><b>10.2.15 tts:fontShear</b></a></p></li><li><p><a href="#style-attribute-fontSelectionStrategy"><b>10.2.14 tts:fontSelectionStrategy</b></a></p></li><li><p><a href="#style-attribute-fontSize"><b>10.2.16 tts:fontSize</b></a></p></li><li><p><a href="#style-attribute-fontStyle"><b>10.2.17 tts:fontStyle</b></a></p></li><li><p><a href="#style-attribute-fontVariantPosition"><b>10.2.18 tts:fontVariantPosition</b></a></p></li><li><p><a href="#style-attribute-fontWeight"><b>10.2.19 tts:fontWeight</b></a></p></li><li><p><a href="#style-attribute-height"><b>10.2.20 tts:height</b></a></p></li><li><p><a href="#style-attribute-letterSpacing"><b>10.2.21 tts:letterSpacing</b></a></p></li><li><p><a href="#style-attribute-lineHeight"><b>10.2.22 tts:lineHeight</b></a></p></li><li><p><a href="#style-attribute-opacity"><b>10.2.23 tts:opacity</b></a></p></li><li><p><a href="#style-attribute-origin"><b>10.2.24 tts:origin</b></a></p></li><li><p><a href="#style-attribute-overflow"><b>10.2.25 tts:overflow</b></a></p></li><li><p><a href="#style-attribute-padding"><b>10.2.26 tts:padding</b></a></p></li><li><p><a href="#style-attribute-position"><b>10.2.27 tts:position</b></a></p></li><li><p><a href="#style-attribute-ruby"><b>10.2.28 tts:ruby</b></a></p></li><li><p><a href="#style-attribute-rubyAlign"><b>10.2.29 tts:rubyAlign</b></a></p></li><li><p><a href="#style-attribute-rubyOffset"><b>10.2.30 tts:rubyOffset</b></a></p></li><li><p><a href="#style-attribute-rubyPosition"><b>10.2.31 tts:rubyPosition</b></a></p></li><li><p><a href="#style-attribute-showBackground"><b>10.2.32 tts:showBackground</b></a></p></li><li><p><a href="#style-attribute-textAlign"><b>10.2.33 tts:textAlign</b></a></p></li><li><p><a href="#style-attribute-textCombine"><b>10.2.34 tts:textCombine</b></a></p></li><li><p><a href="#style-attribute-textDecoration"><b>10.2.35 tts:textDecoration</b></a></p></li><li><p><a href="#style-attribute-textEmphasis"><b>10.2.36 tts:textEmphasis</b></a></p></li><li><p><a href="#style-attribute-textOrientation"><b>10.2.37 tts:textOrientation</b></a></p></li><li><p><a href="#style-attribute-textOutline"><b>10.2.38 tts:textOutline</b></a></p></li><li><p><a href="#style-attribute-textShadow"><b>10.2.39 tts:textShadow</b></a></p></li><li><p><a href="#style-attribute-unicodeBidi"><b>10.2.40 tts:unicodeBidi</b></a></p></li><li><p><a href="#style-attribute-visibility"><b>10.2.41 tts:visibility</b></a></p></li><li><p><a href="#style-attribute-width"><b>10.2.42 tts:width</b></a></p></li><li><p><a href="#style-attribute-wrapOption"><b>10.2.43 tts:wrapOption</b></a></p></li><li><p><a href="#style-attribute-writingMode"><b>10.2.44 tts:writingMode</b></a></p></li><li><p><a href="#style-attribute-zIndex"><b>10.2.45 tts:zIndex</b></a></p></li></ul><table border="1" class="ednote" summary="Editorial note: Additional Border Styling Attributes"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Additional Border Styling Attributes</b></td><td align="right" valign="top">2013-08-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Consider adding support for <code>tts:borderColor</code>, <code>tts:borderStyle</code>, and <code>tts:borderWidth</code>
-in order to provide a means to independently express styling of the four different borders (top, right, bottom, left). As currently specified, i.e., with only the
-<code>tts:border</code> attribute, one can only express the four borders using the same color, style, and width.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Clip, Origin, Size"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Clip, Origin, Size</b></td><td align="right" valign="top">2014-11-27</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Consider adding support for <code>tts:backgroundClip</code>,
-<code>tts:backgroundOrigin</code>, and
-<code>tts:backgroundSize</code>.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: Additional Width/Height Related Attributes"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Additional Width/Height Related Attributes</b></td><td align="right" valign="top">2014-11-30</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Given the addition of <code>tts:width</code> and <code>tts:height</code>, consider also adding
-<code>tts:minWidth</code>, <code>tts:maxWidth</code>, <code>tts:minHeight</code>, and <code>tts:minHeight</code>.</td></tr></table><p>Unless explicitly permitted by an element type definition, an attribute in the TT Style Namespace should not be specified on an element
-unless it either applies to that element or denotes an inheritable style property. If it does not apply to that element
-and does not denote an inheritable style property, then it must be ignored for the purpose of non-validation processing.
-In the case of validation processing, such usage should be reported as a warning, or, if strict validation is performed,
-as an error.</p><p>Unless explicitly stated otherwise, linear white-space (LWSP) must
-appear between adjacent non-terminal components of a value of a TT
-Style property value unless some other delimiter is permitted and used.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification makes use of <em>lowerCamelCased</em> local
-names for style attributes that
-are based upon like-named properties defined by <a href="#xsl11">[XSL 1.1]</a>.
-This convention is likewise extended to token values of such
-properties.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>An inheritable style property may be expressed as a specified attribute on the
-root <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element or on a
-<a href="#terms-content-element">content element</a> type
-independently of whether the property applies to that
-element type. This capability permits the expression of an inheritable
-style property on ancestor elements to which the property
-does not apply.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>Due to the general syntax of this specification (and the schemas it references) with respect
-to how style attributes are specified, particularly for the purpose of supporting inheritance,
-it is possible for an author to inadvertently specify a non-inheritable style attribute on
-an element that applies neither to that element or any of its descendants while still remaining
-conformant from a content validity perspective. Content authors may wish to make use of TTML
-content verification tools that detect and warn about such usage.</p></div><div class="div3">
-<h4><a id="style-attribute-style"></a>10.2.1 style</h4><p>The <code>style</code> attribute is used by referential style association
-to reference one or more <code>style</code> elements each of which define a style (property) set.</p><p>The <code>style</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#animation-vocabulary-animate"><code>animate</code></a></p></li><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-br"><code>br</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#animation-vocabulary-set"><code>set</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li><li><p><a href="#styling-vocabulary-style"><code>style</code></a></p></li></ul><p>If specified, the value of a <code>style</code> attribute must
-adhere to the <code>IDREFS</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§ 3.3.10, and, furthermore, each IDREF must reference a <code>style</code> element
-which has a <code>styling</code> element as an ancestor.</p><p>If the same IDREF, <em>ID<sub>1</sub></em>, appears more than one time in the value of a <code>style</code>
-attribute, then there should be an intervening IDREF, <em>ID<sub>2</sub></em>, where 
-<em>ID<sub>2</sub></em> is not equal to <em>ID<sub>1</sub></em>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This constraint is intended to discourage the use of redundant referential styling while still
-allowing the same style to be referenced multiple times in order to potentially override prior
-referenced styles, e.g., when an intervening, distinct style is referenced in the IDREFS list.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>See the specific element type definitions that permit use of the
-<code>style</code> attribute, as well as <a href="#semantics-style-association-referential"><b>10.4.1.2 Referential Styling</b></a> and <a href="#semantics-style-association-chained-referential"><b>10.4.1.3 Chained Referential Styling</b></a>, for
-further information on its semantics.</p></div></div><div class="div3">
-<h4><a id="style-attribute-backgroundColor"></a>10.2.2 tts:backgroundColor</h4><p>The <code>tts:backgroundColor</code> attribute is used to specify a style property that
-defines the background color of a region or an area generated by content flowed into a region.</p><div class="issue"><p class="prefix"><a id="issue-302"></a><b>Issue (issue-302):</b></p><p class="prefix"><b>Line Area Background Height</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/302">http://www.w3.org/AudioVideo/TT/tracker/issues/302</a></p><p>Fix definition of block progression dimension of background area of a line area. Neither XSL-FO nor CSS are sufficiently precise.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-backgroundColor"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-color">&lt;color&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>transparent</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The <code>tts:backgroundColor</code> style is illustrated by the following example.</p><a id="style-attribute-backgroundColor-example-1"></a><table class="example"><caption>Example Fragment – Background Color</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="306px 114px"/&gt;
-  &lt;style <span class="strong">tts:backgroundColor="red"</span>/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:padding="3px 40px"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1" <span class="strong">tts:backgroundColor="purple"</span> tts:textAlign="center"&gt;
-  Twinkle, twinkle, little bat!&lt;br/&gt;
-  How &lt;span <span class="strong">tts:backgroundColor="green"</span>&gt;I wonder&lt;/span&gt; where you're at!
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-backgroundColor-example-1-images"></a><table class="example-images"><caption>Example Rendition – Background Color</caption><tbody><tr><td><img src="images/backgroundColor.png" alt="TTML backgroundColor style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.8.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-backgroundImage"></a>10.2.3 tts:backgroundImage</h4><p>The <code>tts:backgroundImage</code> attribute is used to specify a style property that
-designates a background <a href="#non-content-image">non-content image</a> to be rendered as
-the background image of a region or an area generated by content flowed into a region.</p><p>A <code>tts:backgroundImage</code> attribute should not make reference to a <a href="#content-image">content image</a>
-used to represent actual content, such as a raster image rendering of a caption. Rather, the use of <code>tts:backgroundImage</code>
-should be limited to styling the background of an element where the content is represented by other means. If it is necessary
-to represent content using a raster image, then it should be expressed by means of an <a href="#embedded-content-vocabulary-image"><code>image</code></a>
-element in a block or inline context.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-backgroundImage"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#embedded-content-value-image">&lt;image&gt;</a> |
-none
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>An <a href="#embedded-content-value-image">&lt;image&gt;</a> expression used with this style property may directly reference an external <a href="#terms-image-resource">image resource</a>;
-however, authors should refrain from doing so, and instead, constrain their usage to only refer to <a href="#embedded-content-vocabulary-image"><code>image</code></a>
-children of a <a href="#embedded-content-vocabulary-resources"><code>resources</code></a> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Referring indirectly to an image by means of an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element makes it possible to
-specify an image as an <a href="#terms-embedded-data-resource">embedded data resource</a>, and specify
-additional information about the image, such as its content type, etc. Furthermore, by exploiting the use of multiple
-<a href="#embedded-content-vocabulary-source"><code>source</code></a> children in an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element,
-it becomes possible to specify resolution specific images and fallback <a href="#terms-image-resource">image resources</a>.</p></div><p>The <code>tts:backgroundImage</code> style is illustrated by the following example.</p><a id="style-attribute-backgroundImage-example-1"></a><table class="example"><caption>Example Fragment – Background Image using Embedded Image Resource</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;head&gt;
-  &lt;resources&gt;
-    &lt;image xml:id="embeddedImage"&gt;
-      &lt;source&gt;
-        &lt;data type="image/png" length="119"&gt;
-          iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-          YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-        &lt;/data&gt;
-      &lt;/source&gt;
-    &lt;/image&gt;
-  &lt;/resources&gt;
-&lt;/head&gt;
-...
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="306px 114px"/&gt;
-  &lt;style tts:backgroundImage="red"/&gt;
-  &lt;style <span class="strong">tts:backgroundImage="#embeddedImage"</span>/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:padding="3px 40px"/&gt;
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Image Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Image Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundImage example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.8.3.</p></div></div><div class="div3">
-<h4><a id="style-attribute-backgroundPosition"></a>10.2.4 tts:backgroundPosition</h4><p>The <code>tts:backgroundPosition</code> attribute is used to specify a style property that
-defines whether and how a background image is positioned in a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-backgroundPosition"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-position">&lt;position&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>0% 0%</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>see prose</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>A percentage value component for a horizontal position offset is relative to the width of the
-positioning area minus the width of the background image.
-A percentage value component for a vertical position offset is relative to the height of the
-positioning area minus the height of the background image.
-The positioning area corresponds with the padding rectangle (padding box) of each area generated
-by applicable element.</p><p>The <code>tts:backgroundPosition</code> style is illustrated by the following example.</p><a id="style-attribute-backgroundPosition-example-1"></a><table class="example"><caption>Example Fragment – Background Position</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="306px 114px"/&gt;
-  &lt;style tts:backgroundImage="#embeddedImage"/&gt;
-  &lt;style <span class="strong">tts:backgroundPosition="center"</span>/&gt;
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Position Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Position Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundPosition example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#css2">[CSS2]</a>, § 14.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-backgroundRepeat"></a>10.2.5 tts:backgroundRepeat</h4><p>The <code>tts:backgroundRepeat</code> attribute is used to specify a style property that
-defines whether and how a background image is repeated (tiled) into a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-backgroundRepeat"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>repeat</code> |
-<code>repeatX</code> |
-<code>repeatY</code> |
-<code>noRepeat</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>repeat</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The <code>tts:backgroundRepeat</code> style is illustrated by the following example.</p><a id="style-attribute-backgroundRepeat-example-1"></a><table class="example"><caption>Example Fragment – Background Repeat</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="306px 114px"/&gt;
-  &lt;style tts:backgroundImage="#embeddedImage"/&gt;
-  &lt;style <span class="strong">tts:backgroundRepeat="repeatX"</span>/&gt;
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Repeat Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Repeat Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundRepeat example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.8.4.</p></div></div><div class="div3">
-<h4><a id="style-attribute-border"></a>10.2.6 tts:border</h4><p>The <code>tts:border</code> attribute is used to specify a style property that
-defines the border of a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-border"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-[
-<a href="#style-value-borderWidth">&lt;borderWidth&gt;</a> ||
-<a href="#style-value-borderStyle">&lt;borderStyle&gt;</a> ||
-<a href="#style-value-borderColor">&lt;borderColor&gt;</a>
-]
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous (color and width only)</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If no border width is specified in the value of the <code>tts:border</code> property,
-then the border width must be interpreted as if a width of
-<code>medium</code> were specified.</p><p>If a computed value of the border width associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the one-dimensional Euclidean distance between
-the computed border width and the supported border width is minimized on a per-edge basis. If there are multiple closest supported values equally distant from
-the computed value for a given edge, then the value least distant from 0, i.e., the least border width, is used.</p></div><p>If no border style is specified in the value of the <code>tts:border</code> property,
-then the border style must be interpreted as if a style of
-<code>none</code> were specified.</p><p>If a computed value of the border style associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>solid</code>.</p><p>If no border color is specified in the value of the <code>tts:border</code> property,
-then the border color must be interpreted as if a color equal
-to the computed value of the element's <code>tts:color</code> style property were specified.</p><p>The <code>tts:border</code> style is illustrated by the following example.</p><a id="style-attribute-border-example-1"></a><table class="example"><caption>Example Fragment – Border</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="306px 114px"/&gt;
-  &lt;style <span class="strong">tts:border="2px solid red"</span>/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:padding="3px 40px"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1" <span class="strong">tts:border="4px solid green"</span> tts:textAlign="center"&gt;
-  Twinkle, twinkle, little bat!&lt;br/&gt;
-  How &lt;span <span class="strong">tts:border="8px solid blue"</span>&gt;I wonder&lt;/span&gt; where you're at!
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Border Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Border Example Image</b></td><td align="right" valign="top">2013-08-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of border example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.31.3.</p></div></div><div class="div3">
-<h4><a id="style-attribute-color"></a>10.2.7 tts:color</h4><p>The <code>tts:color</code> attribute is used to specify a style property that
-defines the foreground color of marks associated with an area generated by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-color"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-color">&lt;color&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td>see prose</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The initial value of the <code>tts:color</code> property
-is considered to be implementation dependent. In the absence of
-end-user preference information, a conformant <a href="#terms-presentation-processor">presentation processor</a>
-should use an initial value that is highly contrastive to the
-background color of the <a href="#terms-root-container-region">root container region</a>.</p><p>The <code>tts:color</code> style is illustrated by the following example.</p><a id="style-attribute-color-example-1"></a><table class="example"><caption>Example Fragment – Color</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style <span class="strong">tts:color="white"</span>/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  In spring, when woods are &lt;span <span class="strong">tts:color="green"</span>&gt;getting green&lt;/span&gt;,&lt;br/&gt;
-  I'll try and tell you what I mean.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-color-example-1-images"></a><table class="example-images"><caption>Example Rendition – Color</caption><tbody><tr><td><img src="images/color.png" alt="TTML color style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.18.1.</p></div></div><div class="div3">
-<h4><a id="style-attribute-direction"></a>10.2.8 tts:direction</h4><p>The <code>tts:direction</code> attribute is used to specify a style property that
-defines the directionality of an embedding or override according to
-the Unicode bidirectional algorithm.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-direction"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>ltr</code> |
-<code>rtl</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>ltr</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>ltr</code>.</p><p>The <code>tts:direction</code> style is illustrated by the following example.</p><a id="style-attribute-direction-example-1"></a><table class="example"><caption>Example Fragment – Direction</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="265px 84px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  Little birds are playing&lt;br/&gt;
-  Bagpipes on the shore,&lt;br/&gt;
-  &lt;span tts:unicodeBidi="bidiOverride" <span class="strong">tts:direction="rtl"</span>&gt;where the tourists snore.&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-direction-example-1-images"></a><table class="example-images"><caption>Example Rendition – Direction</caption><tbody><tr><td>
-<img src="images/direction.png" alt="TTML direction style property">
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.29.1.</p></div></div><div class="div3">
-<h4><a id="style-attribute-display"></a>10.2.9 tts:display</h4><p>The <code>tts:display</code> attribute is used to specify a style property that
-defines whether an element is a candidate for layout and composition
-in a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-display"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<code>none</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>auto</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If the value of this attribute is <code>auto</code>,
-then the affected element is a candidate for region layout and
-presentation; however, if the value is <code>none</code>, then the
-affected element and its descendants must be considered ineligible for region
-layout and presentation.</p><p>The <code>tts:display</code> style is illustrated by the following example.</p><a id="style-attribute-display-example-1"></a><table class="example"><caption>Example Fragment – Display</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="369px 119px"
-            tts:backgroundColor="black"
-            tts:color="white"
-            tts:displayAlign="before"
-            tts:textAlign="start"/&gt;
-&lt;/region&gt;
-...
-&lt;div region="r1"&gt;
-  &lt;p dur="5s"&gt;
-    [[[
-    &lt;span <span class="strong">tts:display="none"</span>&gt;
-      &lt;set begin="1s" dur="1s" <span class="strong">tts:display="auto"</span>/&gt;
-      Beautiful soup,
-    &lt;/span&gt;
-    &lt;span <span class="strong">tts:display="none"</span>&gt;
-      &lt;set begin="2s" dur="1s" <span class="strong">tts:display="auto"</span>/&gt;
-      so rich and green,
-    &lt;/span&gt;
-    &lt;span <span class="strong">tts:display="none"</span>&gt;
-      &lt;set begin="3s" dur="1s" <span class="strong">tts:display="auto"</span>/&gt;
-      waiting in a hot tureen!
-    &lt;/span&gt;
-    ]]]
-  &lt;/p&gt;
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-display-example-1-images"></a><table class="example-images"><caption>Example Rendition – Display</caption><tbody><tr><td>
-<img src="images/display_0.png" alt="TTML display style property - [0,1)">
-</td></tr><tr><td>
-<img src="images/display_1.png" alt="TTML display style property - [1,2)">
-</td></tr><tr><td>
-<img src="images/display_2.png" alt="TTML display style property - [2,3)">
-</td></tr><tr><td>
-<img src="images/display_3.png" alt="TTML display style property - [3,4)">
-</td></tr><tr><td>
-<img src="images/display_4.png" alt="TTML display style property - [4,5)">
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#css2">[CSS2]</a>, § 9.2.4.</p></div></div><div class="div3">
-<h4><a id="style-attribute-displayAlign"></a>10.2.10 tts:displayAlign</h4><p>The <code>tts:displayAlign</code> attribute is used to specify a style property that
-defines the alignment of block areas in the block progression direction.</p><table border="1" class="ednote" summary="Editorial note: Justification in Block Progression Dimension"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Justification in Block Progression Dimension</b></td><td align="right" valign="top">2015-01-14</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add <code>justify</code> value to support justification in block progression dimension.</td></tr></table><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-displayAlign"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>before</code> |
-<code>center</code> |
-<code>after</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>before</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>before</code>.</p><p>The <code>tts:displayAlign</code> style is illustrated by the following example.</p><a id="style-attribute-displayAlign-example-1"></a><table class="example"><caption>Example Fragment – Display Align</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="128px 66px" tts:origin="0px 0px"
-       tts:backgroundColor="black" tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:displayAlign="before"</span>/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="192px 66px" tts:origin="128px 66px"/&gt;
-       tts:backgroundColor="green" tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:displayAlign="after"</span>/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r3"&gt;
-  &lt;style tts:extent="128px 66px"/&gt; style tts:origin="0px 132px"
-       tts:backgroundColor="black" tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:displayAlign="before"</span>/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r4"&gt;
-  &lt;style tts:extent="192px 66px" tts:origin="128px 198px"/&gt;
-       tts:backgroundColor="green" tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:displayAlign="after"</span>/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-&lt;/region&gt;
-...
-&lt;div&gt;
-  &lt;p region="r1"&gt;I sent a message to the fish:&lt;/p&gt;
-  &lt;p region="r2"&gt;I told them&lt;br/&gt; "This is what I wish."&lt;/p&gt;
-  &lt;p region="r3"&gt;The little fishes of the sea,&lt;/p&gt;
-  &lt;p region="r4"&gt;They sent an&lt;br/&gt; answer back to me.&lt;/p&gt;
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-displayAlign-example-1-images"></a><table class="example-images"><caption>Example Rendition – Display Align</caption><tbody><tr><td><img src="images/displayAlign.png" alt="TTML displayAlign style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.14.4.</p></div></div><div class="div3">
-<h4><a id="style-attribute-extent"></a>10.2.11 tts:extent</h4><p>The <code>tts:extent</code> attribute is used to specify the
-<em>width</em> and <em>height</em> of a region area. It may also be used to specify the extent of
-the <a href="#terms-root-container-region">root container region</a>, which has the effect of defining
-the <a href="#terms-document-coordinate-space">document coordinate space</a>.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-extent"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<code>contain</code> |
-<code>cover</code> |
-<a href="#style-value-measure">&lt;measure&gt;</a> <a href="#style-value-measure">&lt;measure&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>relative to width and height of <a href="#terms-root-container-region">root container region</a></td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If the value of this attribute consists of two <a href="#style-value-measure">&lt;measure&gt;</a>
-specifications, then they must be interpreted as <em>width</em>
-and <em>height</em>, where the first specification is the
-<em>width</em>, and the second specification is the <em>height</em>.</p><p>The <a href="#style-value-measure">&lt;measure&gt;</a> value(s) used to express extent must be non-negative.</p><p>If the value of this attribute is <code>auto</code>, then the computed value
-of the style property must be considered to be the same as the extent of the <a href="#terms-root-container-region">root container region</a>.</p><table border="1" class="ednote" summary="Editorial note: Semantics of contain and cover"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Semantics of contain and cover</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Define semantics of new <code>contain</code> and <code>cover</code> values.</td></tr></table><p>The extent of the <a href="#terms-root-container-region">root container region</a> is determined either by a
-<code>tts:extent</code> specified on the <code>tt</code> element, if
-present, or as described by <a href="#document-structure-vocabulary-tt"><b>8.1.1 tt</b></a> if not present.
-If <code>tts:extent</code> is specified on the <code>tt</code> element, then
-the width and height must be expressed in terms of two <a href="#style-value-length">&lt;length&gt;</a> specifications,
-and these specifications must be expressed as non-percentage, definite lengths using pixel units.</p><p>If a <code>tts:extent</code> attribute is specified on a <code>div</code> or <code>p</code> element, then that specification must be considered to be
-equivalent to specifying an anonymous <a href="#terms-inline-region">inline region</a> child of the <code>div</code> or <code>p</code> element, where the
-extent of the corresponding region, also referred to as an <a href="#terms-implied-inline-region">implied inline region</a>, is equal to the
-value of this attribute.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed extent and the supported extent is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value most distant from [0,0], i.e., of greatest extent, is used.</p><p>This rule for resolving <em>closest supported value</em> makes use of the nearest larger rather than nearest smaller supported distance.
-The rationale for this difference in treatment is
-that use of a larger extent ensures that the affected content will be contained in the region area without causing region overflow,
-while use of a smaller extent makes region overflow more likely.</p></div><p>The <code>tts:extent</code> style is illustrated by the following example.</p><a id="style-attribute-extent-example-1"></a><table class="example"><caption>Example Fragment – Extent</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style <span class="strong">tts:extent="330px 122px"</span>/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  'Tis the voice of the Lobster:&lt;br/&gt;
-  I heard him declare,&lt;br/&gt;
-  "You have baked me too brown,&lt;br/&gt;
-  I must sugar my hair."
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-extent-example-1-images"></a><table class="example-images"><caption>Example Rendition – Extent</caption><tbody><tr><td><img src="images/extent.png" alt="TTML extent style property"></td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-attribute-fontFamily"></a>10.2.12 tts:fontFamily</h4><p>The <code>tts:fontFamily</code> attribute is used to specify a style property that
-defines the font family from which glyphs are selected for glyph areas generated
-by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontFamily"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-(<a href="#style-value-familyName">&lt;familyName&gt;</a> | <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a>)
-(<code>","</code>
-&nbsp;(<a href="#style-value-familyName">&lt;familyName&gt;</a> | <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a>))*
-</td></tr><tr><td><em>Initial:</em></td><td><code>default</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The initial value, <code>default</code>, is a generic font family name, and is
-further described in <a href="#style-value-genericFamilyName"><b>10.3.11 &lt;genericFamilyName&gt;</b></a> below.</p></div><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported, then a
-<a href="#terms-presentation-processor">presentation processor</a> must attempt to map the computed font family
-to a supported font family that has similar typographic
-characteristics, or, in the absence of such a mapping, it must
-use the value <code>default</code>.</p><p>The <code>tts:fontFamily</code> style is illustrated by the following example.</p><a id="style-attribute-fontFamily-example-1"></a><table class="example"><caption>Example Fragment – Font Family</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="474px 146px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-  &lt;style <span class="strong">tts:fontFamily="proportionalSansSerif"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;div region="r1"&gt;
-  &lt;p&gt;
-    "The time has come," the Walrus said,&lt;br/&gt;
-    "to talk of many things:
-  &lt;/p&gt;
-  &lt;p tts:textAlign="end" <span class="strong">tts:fontFamily="monospaceSerif"</span>&gt;
-    Of shoes, and ships, and sealing wax,&lt;br/&gt;
-    Of cabbages and kings,
-  &lt;/p&gt;
-  &lt;p&gt;
-    And why the sea is boiling hot,&lt;br/&gt;
-    and whether pigs have wings."
-  &lt;/p&gt;
-&lt;/div&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-fontFamily-example-1-images"></a><table class="example-images"><caption>Example Rendition – Font Family</caption><tbody><tr><td><img src="images/fontFamily.png" alt="TTML fontFamily style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.9.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-fontKerning"></a>10.2.13 tts:fontKerning</h4><p>The <code>tts:fontKerning</code> attribute is used to specify a style property that
-determines whether font kerning is applied when positioning glyph areas.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontKerning"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-<code>normal</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>normal</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If the value of this attribute is <code>normal</code>, then kerning should be applied if kerning data is available.
-If the value of this attribute is <code>none</code>, then kerning should not be applied whether or not kerning data is available.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>normal</code>.</p><p>The <code>tts:fontKerning</code> style is illustrated by the following
-example.</p><table border="1" class="ednote" summary="Editorial note: Font Kerning Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Font Kerning Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:fontKerning.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#css3-fonts">[CSS Fonts]</a>,
-§ 6.3.</p></div></div><div class="div3">
-<h4><a id="style-attribute-fontSelectionStrategy"></a>10.2.14 tts:fontSelectionStrategy</h4><table border="1" class="ednote" summary="Editorial note: Define tts:fontSelectionStrategy"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Define tts:fontSelectionStrategy</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Define <code>tts:fontSelectionStrategy</code> style property based on
-the XSL 1.1 <a href="http://www.w3.org/TR/xsl/#font-selection-strategy">font-selection-strategy</a> and
-recent <a href="http://lists.w3.org/Archives/Public/public-tt/2014Nov/0051.html">TTWG ML thread</a>.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: Font Selection"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Font Selection</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Specify font selection semantics, including how multiple author defined <a href="#terms-font-resource">font resources</a> combine
-with (local) platform defined <a href="#terms-font-resource">font resources</a> to obtain an ordered list of <a href="#terms-font-resource">font resources</a> for performing
-character to glyph mapping.</td></tr></table></div><div class="div3">
-<h4><a id="style-attribute-fontShear"></a>10.2.15 tts:fontShear</h4><p>The <code>tts:fontShear</code> attribute is used to specify a style property that
-determines whether and how a shear transformation is applied to glyph areas.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontShear"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-length">&lt;percentage&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>0%</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>see prose</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If the value of this attribute is <code>0%</code>, then no shear transformation is applied; if the value is <code>100%</code>, then a 2D shear transformation
-of 90 degrees is applied in the axis associated with the inline progression direction; if the value is <code>-100%</code>, then a shear transformation
-of -90 degrees is applied. If the absolute value of the specified percentage is greater than 100%, then it must be interpreted as if 100% were specified with
-the appropriate sign.</p><p>If the inline progression direction corresponds to the X axis, then the 2D shear transformation is described by the following matrix:</p><div class="exampleInner"><pre>
-| 1 <em>a</em> 0 |
-| 0 1 0 |
-| 0 0 1 |
-</pre></div><p>where <em>a</em> is equal to the tangent of the shear angle.</p><p>If the inline progression direction corresponds to the Y axis, then the 2D shear transformation is described by the following matrix:</p><div class="exampleInner"><pre>
-| 1 0 0 |
-| <em>a</em> 1 0 |
-| 0 0 1 |
-</pre></div><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The <code>tts:fontShear</code> style is illustrated by the following
-example.</p><table border="1" class="ednote" summary="Editorial note: Font Shear Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Font Shear Example</b></td><td align="right" valign="top">2015-01-07</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:fontShear.</td></tr></table></div><div class="div3">
-<h4><a id="style-attribute-fontSize"></a>10.2.16 tts:fontSize</h4><p>The <code>tts:fontSize</code> attribute is used to specify a style property
-that defines the font size for glyphs that are selected for glyph areas
-generated by content flowed into a region.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontSize"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a>?
-</td></tr><tr><td><em>Initial:</em></td><td><code>1c</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>if not <a href="#content-vocabulary-span"><code>region</code></a> element,
-then relative to parent element's font size; otherwise, relative to the
-<a href="#terms-computed-cell-size">computed cell size</a></td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If a single <a href="#style-value-length">&lt;length&gt;</a> value is specified, then this length applies
-equally to horizontal and vertical scaling of a glyph's EM square; if two
-<a href="#style-value-length">&lt;length&gt;</a> values are specified, then the first expresses the horizontal
-scaling and the second expresses vertical scaling.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Use of independent horizontal and vertical font sizes is expected to be used
-with cell based units in order to denote fonts that are two rows in height and
-one column in width.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>A glyph's EM square is conventionally defined as the EM square of the font that contains the glyph. That is,
-glyphs do not have an EM square that is distinct from their font's EM square.</p></div><p>If horizontal and vertical sizes are expressed independently, then the
-units of the <a href="#style-value-length">&lt;length&gt;</a> values must be the same.</p><p>The <a href="#style-value-length">&lt;length&gt;</a> value(s) used to express font size must be non-negative.</p><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed font size and the supported font size is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value most distant from 0 (single length specification) or [0,0] (two length specifications) is used,
-i.e., the largest font size, is used.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The expression <code>1c</code> means one cell, where <code>'c'</code> expresses
-the <em>cell</em> length unit as defined by <a href="#style-value-length"><b>10.3.14 &lt;length&gt;</b></a>.
-When a single &lt;length&gt; is expressed using cell units, then it refers to the height of
-the <a href="#terms-computed-cell-size">computed cell size</a>.
-When two &lt;length&gt; values are expressed using cell units, then the first refers to the width of
-the <a href="#terms-computed-cell-size">computed cell size</a>, and the second refers to the height of the
-<a href="#terms-computed-cell-size">computed cell size</a>.</p></div><p>The <code>tts:fontSize</code> style is illustrated by the following example.</p><a id="style-attribute-fontSize-example-1"></a><table class="example"><caption>Example Fragment – Font Size</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="299px 97px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style <span class="strong">tts:fontSize="18px"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  Then fill up the glasses&lt;br/&gt;
-  with treacle and ink,&lt;br/&gt;
-  Or anything else&lt;br/&gt;
-  that is &lt;span <span class="strong">tts:fontSize="24px"</span>&gt;pleasant&lt;/span&gt; to drink.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-fontSize-example-1-images"></a><table class="example-images"><caption>Example Rendition – Font Size</caption><tbody><tr><td><img src="images/fontSize.png" alt="TTML fontSize style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.9.4. The addition of a second length component to permit specifying font
-width and height independently is an extension introduced by TTML.</p></div></div><div class="div3">
-<h4><a id="style-attribute-fontStyle"></a>10.2.17 tts:fontStyle</h4><p>The <code>tts:fontStyle</code> attribute is used to specify a style property that
-defines the font style to apply to glyphs that are selected for glyph areas generated
-by content flowed into a region, where the mapping from font
-style value to specific font face or style parameterization is not determined
-by this specification.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontStyle"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<code>italic</code> |
-<code>oblique</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>normal</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>Use of the value <code>oblique</code>
-denotes a shear transformation (at an unspecified
-angle) in the inline progression dimension.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>normal</code>.</p><p>The <code>tts:fontStyle</code> style is illustrated by the following example.</p><a id="style-attribute-fontStyle-example-1"></a><table class="example"><caption>Example Fragment – Font Style</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="331px 84px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  In autumn, when the leaves are brown,&lt;br/&gt;
-  Take pen and ink, and &lt;span <span class="strong">tts:fontStyle="italic"</span>&gt;write it down.&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-fontStyle-example-1-images"></a><table class="example-images"><caption>Example Rendition – Font Style</caption><tbody><tr><td><img src="images/fontStyle.png" alt="TTML fontStyle style property"></td></tr></tbody></table><p></p><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.9.7.</p></div></div><div class="div3">
-<h4><a id="style-attribute-fontVariantPosition"></a>10.2.18 tts:fontVariantPosition</h4><p>The <code>tts:fontVariantPosition</code> attribute is used to enable the selection
-of typographic subscript and superscript glyphs.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontVariantPosition"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<code>sub</code> |
-<code>super</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>normal</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>normal</code>.</p><table border="1" class="ednote" summary="Editorial note: Font Position Variant Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Font Position Variant Example</b></td><td align="right" valign="top">2014-09-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add example source and rendering of tts:fontVariantPosition.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#css3-fonts">[CSS Fonts]</a>,
-§ 6.5.</p></div></div><div class="div3">
-<h4><a id="style-attribute-fontWeight"></a>10.2.19 tts:fontWeight</h4><p>The <code>tts:fontWeight</code> attribute is used to specify a style property
-that defines the font weight to apply to glyphs that are selected for glyph
-areas generated by content flowed into a region, where the mapping from font
-weight value to specific font face or weight parameterization is not determined
-by this specification.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-fontWeight"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<code>bold</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>normal</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>normal</code>.</p><p>The <code>tts:fontWeight</code> style is illustrated by the following example.</p><a id="style-attribute-fontWeight-example-1"></a><table class="example"><caption>Example Fragment – Font Weight</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="376px 95px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  They told me you had been to her,&lt;br/&gt;
-  &lt;span <span class="strong">tts:fontWeight="bold"</span>&gt;and mentioned me to him:&lt;/span&gt;&lt;br/&gt;
-  She gave me a good character&lt;br/&gt;
-  &lt;span <span class="strong">tts:fontWeight="bold"</span>&gt;but said I could not swim.&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-fontWeight-example-1-images"></a><table class="example-images"><caption>Example Rendition – Font Weight</caption><tbody><tr><td><img src="images/fontWeight.png" alt="TTML fontWeight style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.9.9.</p></div></div><div class="div3">
-<h4><a id="style-attribute-height"></a>10.2.20 tts:height</h4><p>The <code>tts:height</code> attribute is used to specify the
-<em>height</em> of an area generated by content flowed into a region.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The term <em>height</em> is interpreted in a writing mode relative manner
-such that <em>height</em> always corresponds to a measure in the block
-progression direction. Therefore, in horizontal writing modes, <em>height</em> expresses a vertical measure,
-while, in vertical writing mode, <em>height</em> expresses a horizontal measure,
-where horizontal and vertical are always interpreted in an absolute sense.</p></div><p>If a <code>tts:height</code> attribute is specified on a <a href="#content-vocabulary-span"><code>span</code></a> element,
-then that <a href="#content-vocabulary-span"><code>span</code></a> element must be processed using
-<a href="#terms-inline-block-display">inline block display</a> semantics for the purpose of presentation processing.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-height"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-measure">&lt;measure&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>,
-<a href="#embedded-content-vocabulary-image"><code>image</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>see prose</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If a <a href="#style-value-measure">&lt;measure&gt;</a> is expressed as a <a href="#style-value-length">&lt;length&gt;</a> value, then it must be non-negative.</p><p>The <code>tts:height</code> style is illustrated by the following example.</p><table border="1" class="ednote" summary="Editorial note: Height Percentage"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Height Percentage</b></td><td align="right" valign="top">2014-11-29</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Specify resolution of percentage value.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: Height Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Height Example</b></td><td align="right" valign="top">2014-11-29</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:height.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.15.6, and <a href="#css3-box">[CSS Box Model]</a>, § 9</p></div></div><div class="div3">
-<h4><a id="style-attribute-letterSpacing"></a>10.2.21 tts:letterSpacing</h4><p>The <code>tts:letterSpacing</code> attribute is used to specify a style property that
-increases or decreases the nominal distance between glyph areas.</p><p>Letter spacing has no affect at the beginning or ending of a line area, and must not
-be applied to zero-width glyphs. Furthermore, letter spacing must not cause normally connected glyphs,
-e.g., as used in cursive scripts or with cursive fonts, to become disconnected.</p><p>Letter spacing is applied independently from kerning and justification. Depending upon the font(s) in use,
-the script(s) being presented, and the capabilities of a presentation processor, either or both kerning and
-justification may be applied in addition to letter spacing.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-letterSpacing"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>normal</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The value <code>normal</code> corresponds to specifying a <a href="#style-value-length">&lt;length&gt;</a> value of zero (0),
-i.e., neither expand nor compress adjacent glyph spacing.</p><p>If a <a href="#style-value-length">&lt;length&gt;</a> value is expressed as a positive scalar,
-then the spaces between adjacent glyphs are expanded by an additional amount equal to that scalar value.
-If expressed as a negative scalar,
-then the spaces between adjacent glyphs are compressed by an additional amount equal to that scalar value, possibly resulting
-in overlapping glyph areas, up to a maximum amount that results an effective advance of zero (0).</p><p>If a computed value of the letter spacing associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the one-dimensional Euclidean distance between
-the computed letter spacing and the supported letter spacing is minimized. If there are multiple closest supported values equally distant from
-the computed value for a given edge, then the value least distant from 0 is used.</p></div><p>The <code>tts:letterSpacing</code> style is illustrated by the following
-example.</p><table border="1" class="ednote" summary="Editorial note: Letter Spacing Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Letter Spacing Example</b></td><td align="right" valign="top">2014-11-30</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:letterSpacing.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#css3-text">[CSS Text]</a>,
-§ 8.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-lineHeight"></a>10.2.22 tts:lineHeight</h4><p>The <code>tts:lineHeight</code> attribute is used to specify a style property that
-defines the inter-baseline separation between line areas generated by content flowed into a region.</p><div class="issue"><p class="prefix"><a id="issue-284"></a><b>Issue (issue-284):</b></p><p class="prefix"><b>Normal Line Height Multiplier</b></p><p><b>Source</b>: <a href="https://www.w3.org/AudioVideo/TT/tracker/issues/284">https://www.w3.org/AudioVideo/TT/tracker/issues/284</a></p><p>Re-visit choice of 120% versus 125% for multiplier used in interpreting <code>normal</code> line height.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-lineHeight"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>normal</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to this element's font size</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If the value of this attribute is <code>normal</code>, then the
-computed value of this style property is determined as follows:</p><ol class="enumar"><li><p>
-Let <em>P</em> be the <code>p</code> element to which this style property applies.
-</p></li><li><p>
-Let <em>FF</em> be the computed value of the <code>tts:fontFamily</code> style property that applies to <em>P</em>.
-</p></li><li><p>
-Let <em>FS</em> be the computed value of the <code>tts:fontSize</code> style property that applies to <em>P</em>.
-</p></li><li><p>
-Let <em>F0</em> be the first font obtained when sequentially mapping each font family in <em>FF</em> to a set of available fonts,
-where this set of available fonts is constrained as needed to satisfy the computed values of the <code>tts:fontStyle</code> and <code>tts:fontWeight</code>
-style properties that apply to <em>P</em>.
-</p></li><li><p>
-If <em>F0</em> is associated with font metrics that specify altitude <em>A</em>, descent <em>D</em>, and line gap <em>G</em>,
-then set <em>LH</em> to the sum of scaled(<em>A</em>), scaled(<em>D</em>), and scaled(<em>G</em>),
-where scaled(<em>X</em>) denotes font metric <em>X</em> scaled according to font size <em>FS</em>.
-</p></li><li><p>
-Otherwise, set <em>LH</em> to 125% of <em>FS</em>.
-</p></li><li><p>
-Set the computed value of this style property to <em>LH</em>.
-</p></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>If a content author wishes to avoid the possibility of different interpretations of <code>normal</code>, for example, due to differences in
-the set of available fonts, then it is recommended that a 
-<a href="#style-value-length">&lt;length&gt;</a> value expression be used to explicitly specify line height value.</p></div><p>If specified as a <a href="#style-value-length">&lt;length&gt;</a>, then the length must
-be non-negative.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed line height and the supported line height is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value most distant from 0, i.e., the largest line height, is used.</p></div><p>The <code>tts:lineHeight</code> style is illustrated by the following example.</p><a id="style-attribute-lineHeight-example-1"></a><table class="example"><caption>Example Fragment – Line Height</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="255px 190px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="16px"/&gt;
-  &lt;style <span class="strong">tts:lineHeight="32px"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  He thought he saw an elephant,&lt;br/&gt;
-  That practised on a fife:&lt;br/&gt;
-  He looked again, and found it was&lt;br/&gt;
-  A letter from his wife.&lt;br/&gt;
-  "At length I realise," he said,&lt;br/&gt;
-  "The bitterness of Life.
-"&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-lineHeight-example-1-images"></a><table class="example-images"><caption>Example Rendition – Line Height</caption><tbody><tr><td><img src="images/lineHeight.png" alt="TTML lineHeight style property"></td></tr></tbody></table><p></p><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.16.4. Furthermore, it is the intention of this specification that the
-allocation rectangle of a line be consistent with the <span class="strong">per-inline-height-rectangle</span>
-as defined by <a href="#xsl11">[XSL 1.1]</a>, § 4.5, i.e., that a CSS-style line box stacking strategy be used.
-</p></div></div><div class="div3">
-<h4><a id="style-attribute-opacity"></a>10.2.23 tts:opacity</h4><p>The <code>tts:opacity</code> attribute is used to specify a style property that
-defines the opacity (or conversely, the transparency)
-of marks associated with a region or an area generated by content flowed into a region.</p><p>When presented onto a visual medium, the opacity of the region is applied uniformly and on a linear scale
-to all marks produced by content targeted to the
-region after having applied applied any content element specific opacity to areas generated by that content.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-opacity"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-alpha">&lt;alpha&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>1.0</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>The <code>tts:opacity</code> style is illustrated by the following example.</p><table border="1" class="ednote" summary="Editorial note: Enhance Opacity Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Enhance Opacity Example</b></td><td align="right" valign="top">2013-08-26</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Enhance opacity example to demonstrate opacity on content elements.</td></tr></table><p></p><a id="style-attribute-opacity-example-1"></a><table class="example"><caption>Example Fragment – Opacity</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1" dur="5s"&gt;
-  &lt;set begin="0s" dur="1s" <span class="strong">tts:opacity="1.00"</span>/&gt;
-  &lt;set begin="1s" dur="1s" <span class="strong">tts:opacity="0.75"</span>/&gt;
-  &lt;set begin="2s" dur="1s" <span class="strong">tts:opacity="0.50"</span>/&gt;
-  &lt;set begin="3s" dur="1s" <span class="strong">tts:opacity="0.25"</span>/&gt;
-  &lt;set begin="4s" dur="1s" <span class="strong">tts:opacity="0.00"</span>/&gt;
-  &lt;style tts:extent="304px 77px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  The sun was shining on the sea
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-opacity-example-1-images"></a><table class="example-images"><caption>Example Rendition – Opacity</caption><tbody><tr><td>
-<img src="images/opacity_0.png" alt="TTML opacity style property - [0,1)">
-</td></tr><tr><td>
-<img src="images/opacity_1.png" alt="TTML opacity style property - [1,2)">
-</td></tr><tr><td>
-<img src="images/opacity_2.png" alt="TTML opacity style property - [2,3)">
-</td></tr><tr><td>
-<img src="images/opacity_3.png" alt="TTML opacity style property - [3,4)">
-</td></tr><tr><td>
-<img src="images/opacity_4.png" alt="TTML opacity style property - [4,5)">
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#css3-color">[CSS3 Color]</a>,
-§ 3.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-origin"></a>10.2.24 tts:origin</h4><p>The <code>tts:origin</code> attribute is used to specify the
-<em>x</em> and <em>y</em> coordinates of the origin of a
-region area with respect to the origin of the <a href="#terms-root-container-region">root container region</a>.</p><p>If both <code>tts:origin</code> and <a href="#style-attribute-position"><code>tts:position</code></a> attributes are
-specified on an element and <a href="#style-attribute-position"><code>tts:position</code></a> is a supported property,
-then the <code>tts:origin</code> attribute must be ignored for the purpose of presentation processing.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-origin"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>relative to width and height of <a href="#terms-root-container-region">root container region</a></td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If the value of this attribute consists of two <a href="#style-value-length">&lt;length&gt;</a> specifications,
-then they must be interpreted as <em>x</em> and <em>y</em> coordinates, where the first specification
-is the <em>x</em> coordinate, and the second specification is the <em>y</em> coordinate.</p><p>If the value of this attribute is <code>auto</code>, then the computed value
-of the style property must be considered to be the same as the origin of the <a href="#terms-root-container-region">root container region</a>.</p><p>If a <code>tts:origin</code> attribute is specified on a <code>div</code> or <code>p</code> element, then that specification must be considered to be
-equivalent to specifying an anonymous <a href="#terms-inline-region">inline region</a> child of the <code>div</code> or <code>p</code> element, where the
-origin of the corresponding region, also referred to as an <a href="#terms-implied-inline-region">implied inline region</a>, is equal to the
-value of this attribute.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed origin and the supported origin is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value least distant from [0,0], i.e., closest to the coordinate space origin, is used.</p></div><p>The <code>tts:origin</code> style is illustrated by the following example.</p><a id="style-attribute-origin-example-1"></a><table class="example"><caption>Example Fragment – Origin</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style <span class="strong">tts:origin="40px 40px"</span>/&gt;
-  &lt;style tts:extent="308px 92px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  "To dine!" she shrieked in dragon-wrath.&lt;br/&gt;
-  "To swallow wines all foam and froth!&lt;br/&gt;
-   To simper at a table-cloth!"
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-origin-example-1-images"></a><table class="example-images"><caption>Example Rendition – Origin</caption><tbody><tr><td><img src="images/origin.png" alt="TTML origin style property"></td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-attribute-overflow"></a>10.2.25 tts:overflow</h4><p>The <code>tts:overflow</code> attribute is used to specify a style property that
-defines whether a region area is clipped or not if the descendant areas of the region overflow
-its extent.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-overflow"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>visible</code> |
-<code>hidden</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>hidden</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute is <code>visible</code>, then content should
-not be clipped outside of the affected region.
-If the value is <code>hidden</code>, then content should
-be clipped outside of the affected region.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Unless a manual line break element <code>br</code> is used by the content author,
-a paragraph of a given region will generate no more than one line area in that
-region if the computed values of the <code>tts:overflow</code> and <code>tts:wrapOption</code>
-style properties of the region are <code>visible</code> and <code>noWrap</code>,
-respectively.</p></div><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>hidden</code>.</p><p>The <code>tts:overflow</code> style is illustrated by the following example.</p><a id="style-attribute-overflow-example-1"></a><table class="example"><caption>Example Fragment – Overflow</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="232px 40px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="red"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="18px"/&gt;
-  &lt;style tts:wrapOption="noWrap"/&gt;
-  &lt;style <span class="strong">tts:overflow="visible"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="232px 40px"/&gt;
-  &lt;style tts:origin="0px 43px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="red"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="18px"/&gt;
-  &lt;style tts:wrapOption="noWrap"/&gt;
-  &lt;style <span class="strong">tts:overflow="hidden"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  "But wait a bit," the Oysters cried,&lt;br/&gt;
-  "Before we have our chat;
-&lt;/p&gt;
-&lt;p region="r2"&gt;
-  For some of us are out of breath,&lt;br/&gt;
-  And all of us are fat!"
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-overflow-example-1-images"></a><table class="example-images"><caption>Example Rendition – Overflow</caption><tbody><tr><td><img src="images/overflow.png" alt="TTML overflow style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the <code>tts:noWrap</code> is set to
-<code>noWrap</code> to prevent automatic line wrapping (breaking);
-if this were not specified, then overflow would occur in the block
-progression direction as opposed to the inline progression direction.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.21.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-padding"></a>10.2.26 tts:padding</h4><p>The <code>tts:padding</code> attribute is used to specify padding (or inset)
-space on one or more sides of a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-padding"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-length">&lt;length&gt;</a> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>0px</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>relative to width and height of containing region</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If the value of this attribute consists of one <a href="#style-value-length">&lt;length&gt;</a> specification,
-then that length applies to all edges of the affected areas. If the value
-consists of two <a href="#style-value-length">&lt;length&gt;</a> specifications, then the first applies to the
-before and after edges, and the second applies to the start and end edges.
-If three <a href="#style-value-length">&lt;length&gt;</a> specifications are provided, then the first applies to the
-before edge, the second applies to the start and end edges, and the third applies
-to the after edge.
-If four <a href="#style-value-length">&lt;length&gt;</a> specifications are provided, then they apply to before, end,
-after, and start edges, respectively.</p><p>The <a href="#style-value-length">&lt;length&gt;</a> value(s) used to express padding must be non-negative.</p><p>If padding is applied to a <a href="#content-vocabulary-span"><code>span</code></a> element, and content from that element
-is divided across multiple line areas, then the specified padding must be applied at each line break boundary. In contrast,
-within a single line area, if multiple inline areas are generated by the element, then the specified padding must be applied at
-the first and/or last generated inline area within a line area the inline progression order of the containing block level element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The behavior of padding on a <a href="#content-vocabulary-span"><code>span</code></a> element corresponds with the use of
-a CSS <code>box-decoration-break</code> property with the value <code>clone</code> at line breaks and the value <code>slice</code>
-at non-terminal, i.e., non-first and non-last, inline area boundaries, as defined by <a href="#css3-frag">[CSS Fragmentation]</a>, § 5.4.</p></div><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the one-dimensional Euclidean distance between
-the computed padding and the supported padding is minimized on a per-edge basis. If there are multiple closest supported values equally distant from
-the computed value for a given edge, then the value least distant from 0, i.e., the least padding, is used.</p></div><p>The <code>tts:padding</code> style is illustrated by the following example.</p><table border="1" class="ednote" summary="Editorial note: Enhance Padding Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Enhance Padding Example</b></td><td align="right" valign="top">2013-08-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Enhance padding example to demonstrate padding on content elements.</td></tr></table><p></p><a id="style-attribute-padding-example-1"></a><table class="example"><caption>Example Fragment – Padding</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="446px 104px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-  &lt;style <span class="strong">tts:padding="10px 40px"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1" tts:backgroundColor="red"&gt;
-  Just the place for a Snark! I have said it twice:&lt;br/&gt;
-  That alone should encourage the crew.&lt;br/&gt;
-  Just the place for a Snark! I have said it thrice:&lt;br/&gt;
-  What I tell you three times is true.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p>When rendering an area to which padding applies, the background color that
-applies to the area is rendered into the padded portion of the area.</p><a id="style-attribute-padding-example-1-images"></a><table class="example-images"><caption>Example Rendition – Padding</caption><tbody><tr><td>
-<img src="images/padding.png" alt="TTML padding style property">
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.31.15, except that individual shorthand values map to writing
-mode relative padding values as defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.8.31, 7.8.32, 7.8.33, and 7.8.34.</p></div></div><div class="div3">
-<h4><a id="style-attribute-position"></a>10.2.27 tts:position</h4><p>The <code>tts:position</code> attribute is used as an alternative way to specify the position
-of a region area with respect the <a href="#terms-root-container-region">root container region</a>.</p><p>If both <code>tts:position</code> and <a href="#style-attribute-origin"><code>tts:origin</code></a> attributes are
-specified on an element and <code>tts:position</code> is a supported property,
-then the <code>tts:origin</code> attribute must be ignored for the purpose of presentation processing.</p><p>This attribute may be specified by any element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-position"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-position">&lt;position&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>center</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>see prose</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>A percentage value component for a horizontal position offset is relative to the width of the
-positioning area minus the width of the associated region.
-A percentage value component for a vertical position offset is relative to the height of the
-positioning area minus the height of the associated region.</p><p>The following image depicts a position value "75% 50%", where the rectangle with dashed line denotes the positioning area and the rectangle
-with solid line denotes the region being positioned. In this case the region is positioned such that a vertical line located at 75% of its width coincides with
-a vertical line located at 75% of the width of the positioning area, and a horizontal line located at 50% of its height coincides with
-a vertical line located at 50% of the width of the posititoning area.</p><a id="style-attribute-position-percentage-based-positioning"></a><table class="example-images"><caption>Percentage Based Positioning</caption><tbody><tr><td>
-<img src="images/position_0.png" alt="TTML position style property using percentages">
-</td></tr></tbody></table><p>If specified on a <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element, then, if a
-<a href="#terms-related-media-object">related media object</a> exists, the positioning area corresponds with
-the <a href="#terms-related-media-object-region">related media object region</a>, or, if no
-<a href="#terms-related-media-object">related media object</a> exists, the positioning area corresponds with
-an unspecified presentation region determined by the <a href="#terms-document-processing-context">document processing context</a>.
-For other applicable element types, the positioning area corresponds with the content rectangle (content box)
-of the <a href="#terms-root-container-region">root container region</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The <a href="#terms-root-container-region">root container region</a> has no border or padding; consequently, its border, padding, and
-content rectangles (boxes) are coterminous.</p></div><p>If a horizontal or vertical position offset is specified by a <code>tts:position</code> attribute in the form of a scalar value
-on a <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element, then that value must be expressed using pixel (<code>px</code>) units,
-in which case a pixel must be interpreted as a pixel in the <a href="#terms-presentation-context-coordinate-space">presentation context coordinate space</a>
-(and not a pixel in the <a href="#terms-document-coordinate-space">document coordinate space</a>).</p><p>If a <code>tts:position</code> attribute is specified on a <a href="#content-vocabulary-div"><code>div</code></a> or
-<a href="#content-vocabulary-p"><code>p</code></a> element, then that specification must be considered to be
-equivalent to specifying an anonymous <a href="#terms-inline-region">inline region</a> child of the <code>div</code> or <code>p</code> element, where the
-position of the corresponding region, also referred to as an <a href="#terms-implied-inline-region">implied inline region</a>, is equal to the
-value of this attribute.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed position and the supported position is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value least distant from [0,0], i.e., closest to the coordinate space position, is used.</p></div><p>The <code>tts:position</code> style is illustrated by the following example, which positions a region so that it is
-centered in the horizontal dimension and has a bottom edge 10% above the bottom of the positioning area in the vertical dimension.</p><a id="style-attribute-position-example-1"></a><table class="example"><caption>Example Fragment – Position</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style <span class="strong">tts:position="center bottom 10%"</span>/&gt;
-  &lt;style tts:extent="308px 92px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  "To dine!" she shrieked in dragon-wrath.&lt;br/&gt;
-  "To swallow wines all foam and froth!&lt;br/&gt;
-   To simper at a table-cloth!"
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Position Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Position Example Image</b></td><td align="right" valign="top">2014-11-28</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of position example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-the <code>background-position</code> property defined by <a href="#css3-bb">[CSS Backgrounds and Borders]</a>, § 3.6.</p></div></div><div class="div3">
-<h4><a id="style-attribute-ruby"></a>10.2.28 tts:ruby</h4><p>The <code>tts:ruby</code> attribute is used to specify the application of ruby
-styling.</p><p>This attribute may be specified by any element type that permits use of attributes in the TT Style Namespace; however,
-this attribute applies as a style property only to those element types indicated in the following table.</p><a id="style-property-details-ruby"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-<code>container</code> |
-<code>base</code> |
-<code>baseContainer</code> |
-<code>text</code> |
-<code>textContainer</code> |
-<code>delimiter</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p></p><p>If the value of this attribute is <code>none</code>, then no ruby semantics apply; otherwise, the ruby semantics enumerated by
-<a href="#ruby-semantics-mapping-table"><b>Table 8-1 – Ruby Semantics Mapping</b></a> apply.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>none</code>.</p><a id="ruby-semantics-mapping-table"></a><table class="common"><caption>Table 8-1 – Ruby Semantics Mapping</caption><col width="25%" span="1"><col width="25%" span="1"><col width="25%" span="1"><col width="25%" span="1"><col span="1"><tbody><tr><th>Category</th><th>tts:ruby</th><th>Annotation <a href="#ruby">[Ruby]</a></th><th>CSS display <a href="#cssruby">[CSS Ruby]</a></th></tr><tr><td>Ruby Container</td><td><code>container</code></td><td><code>ruby</code></td><td><code>ruby</code></td></tr><tr><td>Ruby Base Content</td><td><code>base</code></td><td><code>rb</code></td><td><code>ruby-base</code></td></tr><tr><td>Ruby Text Content</td><td><code>text</code></td><td><code>rt</code></td><td><code>ruby-text</code></td></tr><tr><td>Ruby Base Container</td><td><code>baseContainer</code></td><td><code>rbc</code></td><td><code>ruby-base-container</code></td></tr><tr><td>Ruby Text Container</td><td><code>textContainer</code></td><td><code>rtc</code></td><td><code>ruby-text-container</code></td></tr><tr><td>Ruby Fallback Delimiter</td><td><code>delimiter</code></td><td><code>rp</code></td><td><code>none</code> | <code>inline</code></td></tr></tbody></table><p>When using <code>tts:ruby</code>, the following nesting constraints apply:</p><ul><li><p>if the computed value of <code>tts:ruby</code> is <code>container</code>, then the
-computed value of <code>tts:ruby</code> of all ancestor elements is <code>none</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>container</code>, then the
-computed value of <code>tts:ruby</code> of its first child element is <code>baseContainer</code>
-or <code>base</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>baseContainer</code>, then the
-computed value of <code>tts:ruby</code> of its parent element is <code>container</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>baseContainer</code>, then the
-computed value of <code>tts:ruby</code> of its first child element is <code>base</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>baseContainer</code>, then its
-preceding sibling is <code>null</code> (i.e., no preceding sibling);</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>textContainer</code>, then the
-computed value of <code>tts:ruby</code> of its parent element is <code>container</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>textContainer</code>, then the
-computed value of <code>tts:ruby</code> of its first child element is either <code>text</code> or <code>delimiter</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>textContainer</code>, then the
-computed value of <code>tts:ruby</code> of its preceding sibling is <code>baseContainer</code> or
-<code>textContainer</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>textContainer</code>, then the
-computed value of <code>tts:ruby</code> of no more than one sibling is <code>textContainer</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>base</code>, then the
-computed value of <code>tts:ruby</code> of its parent element is either <code>container</code> or
-<code>baseContainer</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>base</code>, then its
-preceding sibling is either <code>null</code> (i.e., no preceding sibling) or the
-computed value of <code>tts:ruby</code> of its preceding sibling is <code>base</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>base</code> and the
-computed value of <code>tts:ruby</code> of its parent element is <code>container</code>,
-then the computed value of <code>tts:ruby</code> of no sibling is <code>base</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>base</code>, then the
-computed value of <code>tts:ruby</code> of no descendant element is not <code>none</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>text</code>, then the
-computed value of <code>tts:ruby</code> of its parent element is either <code>container</code> or
-<code>textContainer</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>text</code>, then the
-computed value of <code>tts:ruby</code> of its preceding sibling is <code>base</code>,
-<code>text</code>, or <code>delimiter</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>text</code> and the
-computed value of <code>tts:ruby</code> of its parent element is <code>container</code>,
-then the computed value of <code>tts:ruby</code> of no sibling is <code>text</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>text</code>, then the
-computed value of <code>tts:ruby</code> of no descendant element is not <code>none</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>delimiter</code>, then the
-computed value of <code>tts:ruby</code> of its parent element is either <code>container</code> or <code>textContainer</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>delimiter</code>, then the
-computed value of <code>tts:ruby</code> of its preceding sibling is <code>base</code> or
-<code>text</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>delimiter</code>, then the
-computed value of <code>tts:ruby</code> of exactly one sibling is <code>delimiter</code>;</p></li><li><p>if the computed value of <code>tts:ruby</code> is <code>delimiter</code>, then the
-computed value of <code>tts:ruby</code> of no descendant element is not <code>none</code>;</p></li></ul><p>A validating processor must treat a violation of any of the above constraints as an error.
-For the purpose of presentation processing, the violation of any of these constraints should result in fallback (inline)
-presentation of ruby text annotations.</p><p>When performing normal presentation processing of ruby text annotations, delimiter content must not generate any
-inline areas. When performing fallback presentation of ruby, both delimiter and non-delimiter ruby (base and text) content
-must generate normal inline areas.</p><p>If a presentation processor does not support ruby presentation, then it must perform fallback ruby presentaton.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The above listed constraints are intended to be interpreted as specifying the following nesting model:</p><div class="exampleInner"><pre>
-container
-  : base text
-  | base delimiter text delimiter
-  | baseContainer textContainer textContainer?
-
-baseContainer
-  : base+
-
-textContainer
-  : text+
-  | delimiter text+ delimiter
-
-base | text | delimiter
-  : ( #PCDATA | { span - tts:ruby } )*
-</pre></div><p>This model corresponds to the maximal content model for the <code>ruby</code> element defined by <a href="#ruby">[Ruby]</a>, §2.1,
-with the exception that <code>rtc</code> is effectively extended to permit the optional use of delimiters (<code>rp</code>):</p><div class="exampleInner"><pre>
-ruby
-  : rb rt
-  | rb rp rt rp
-  | rbc rtc rtc?
-
-rbc
-  : rb+
-
-rtc
-  : rt+
-  | rp rt+ rp                            // extension to <a href="#ruby">[Ruby]</a>
-</pre></div></div><div class="note"><p class="prefix"><b>Note:</b></p><p>While not supporting as many opportunities for markup minimization as allowed by <a href="#html5">[HTML5]</a>,
-the formulation of ruby annotation defined here does allow the following shorthands:</p><div class="exampleInner"><pre>
-base text =
-  baseContainer
-    base
-  textContainer
-    text
-
-base delimiter text delimiter =
-  baseContainer
-    base
-  textContainer
-    delimiter text delimiter
-</pre></div><p>Given the content of <code>base</code> is <code>B</code> and the content of
-<code>text</code> is <code>T</code>, then the expression <code>base text</code> could be represented variously in <a href="#html5">[HTML5]</a> as follows:</p><div class="exampleInner"><pre>
-&lt;ruby&gt;B&lt;rt&gt;T&lt;/ruby&gt;
-&lt;ruby&gt;B&lt;rt&gt;T&lt;/rt&gt;&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;rt&gt;T&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;/rb&gt;&lt;rt&gt;T&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;/rb&gt;&lt;rt&gt;T&lt;/rt&gt;&lt;/ruby&gt;
-&lt;ruby&gt;B&lt;rtc&gt;&lt;rt&gt;T&lt;/ruby&gt;
-&lt;ruby&gt;B&lt;rtc&gt;&lt;rt&gt;T&lt;/rtc&gt;&lt;/ruby&gt;
-&lt;ruby&gt;B&lt;rtc&gt;&lt;rt&gt;T&lt;/rt&gt;&lt;/ruby&gt;
-&lt;ruby&gt;B&lt;rtc&gt;&lt;rt&gt;T&lt;/rt&gt;&lt;/rtc&gt;&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;rtc&gt;&lt;rt&gt;T&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;rtc&gt;&lt;rt&gt;T&lt;/rtc&gt;&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;/rb&gt;&lt;rtc&gt;&lt;rt&gt;T&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;/rb&gt;&lt;rtc&gt;&lt;rt&gt;T&lt;/rtc&gt;&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;/rb&gt;&lt;rtc&gt;&lt;rt&gt;T&lt;/rt&gt;&lt;/ruby&gt;
-&lt;ruby&gt;&lt;rb&gt;B&lt;/rb&gt;&lt;rtc&gt;&lt;rt&gt;T&lt;/rt&gt;&lt;/rtc&gt;&lt;/ruby&gt;
-</pre></div><p>Whereas, in TTML2, the following alternative expressions are possible:</p><div class="exampleInner"><pre>
-&lt;span tts:ruby="container"&gt;
-  &lt;span tts:ruby="base"&gt;B&lt;/span&gt;
-  &lt;span tts:ruby="text"&gt;T&lt;/span&gt;
-&lt;/span&gt;
-</pre></div><p>or its equivalent</p><div class="exampleInner"><pre>
-&lt;span tts:ruby="container"&gt;
-  &lt;span tts:ruby="baseContainer"&gt;
-    &lt;span tts:ruby="base"&gt;B&lt;/span&gt;
-  &lt;/span&gt;
-  &lt;span tts:ruby="textContainer"&gt;
-    &lt;span tts:ruby="text"&gt;T&lt;/span&gt;
-  &lt;/span&gt;
-&lt;/span&gt;
-</pre></div></div><p>Use of <code>tts:ruby</code> to specify simple ruby annotation is illustrated by the following example.</p><a id="style-attribute-ruby-example-1"></a><table class="example"><caption>Example Fragment – Simple Ruby</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;span <span class="strong">tts:ruby="container"</span>&gt;
-  &lt;span <span class="strong">tts:ruby="base"</span>&gt;利用許諾&lt;/span&gt;
-  &lt;span <span class="strong">tts:ruby="text"</span>&gt;ライセンス&lt;/span&gt;
-&lt;/span&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-ruby-example-1-images"></a><table class="example-images"><caption>Example Rendition – Simple Ruby</caption><tbody><tr><td><img src="images/ruby_1.png" alt="TTML ruby style property"></td></tr></tbody></table><p>Use of <code>tts:ruby</code> to specify complex ruby annotation is illustrated by the following example.</p><a id="style-attribute-ruby-example-2"></a><table class="example"><caption>Example Fragment – Complex Ruby</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;span&gt;
-  &lt;span <span class="strong">tts:ruby="container"</span>&gt;
-    &lt;span <span class="strong">tts:ruby="baseContainer"</span>&gt;
-      &lt;span <span class="strong">tts:ruby="base"</span>&gt;東南&lt;/span&gt;
-    &lt;/span&gt;
-    &lt;span <span class="strong">tts:ruby="textContainer"</span> tts:rubyPosition="before"&gt;
-      &lt;span <span class="strong">tts:ruby="text"</span>&gt;とうなん&lt;/span&gt;
-    &lt;/span&gt;
-    &lt;span <span class="strong">tts:ruby="textContainer"</span> tts:rubyPosition="after"&gt;
-      &lt;span <span class="strong">tts:ruby="text"</span>&gt;たつみ&lt;/span&gt;
-    &lt;/span&gt;
-  &lt;/span&gt;
-  &lt;span&gt;の方角&lt;/span&gt;
-&lt;/span&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-ruby-example-2-images"></a><table class="example-images"><caption>Example Rendition – Complex Ruby</caption><tbody><tr><td><img src="images/ruby_2.png" alt="TTML ruby style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#ruby">[Ruby]</a> and <a href="#cssruby">[CSS Ruby]</a>. See also
-<a href="#jlreq">[JLREQ]</a>, §3.3, for further information.</p></div></div><div class="div3">
-<h4><a id="style-attribute-rubyAlign"></a>10.2.29 tts:rubyAlign</h4><p>The <code>tts:rubyAlign</code> attribute is used to specify the position of ruby text within the inline area generated by the ruby text container annotation.</p><p>This attribute may be specified by any element type that permits use of attributes in the TT Style Namespace; however,
-this attribute applies as a style property only to those element types indicated in the following table.</p><a id="style-property-details-rubyAlign"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>start</code> |
-<code>center</code> |
-<code>spaceBetween</code> |
-<code>spaceAround</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>spaceAround</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a> only if the computed value of <a href="#style-attribute-ruby">tts:ruby</a> is <code>container</code>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p></p><p>If the value of this attribute is <code>start</code>, then the start edge of the first glyph area descendant of an inline area generated from a ruby text container
-or ruby text annotation is aligned to the start edge of that inline area.
-If the value is <code>center</code>, then excess whitespace
-is equally distributed before and after the first and last glyphs, respectively.
-If the value is <code>spaceBetween</code>, then excess whitespace
-is equally distributed between each glyph area descendant.
-If the value is <code>spaceAround</code>, then excess whitespace
-is equally distributed before and after each glyph area descendant.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>spaceAround</code>.</p><table border="1" class="ednote" summary="Editorial note: Ruby Align Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Ruby Align Example</b></td><td align="right" valign="top">2014-09-20</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add example source and rendering of tts:rubyAlign.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#cssruby">[CSS Ruby]</a>, §4.3, and the examples and example
-renderings shown there apply.</p></div></div><div class="div3">
-<h4><a id="style-attribute-rubyOffset"></a>10.2.30 tts:rubyOffset</h4><p>The <code>tts:rubyOffset</code> attribute is used to specify the offset (distance) of ruby text with respect to its associated ruby base
-in the block progression dimension.</p><p>This attribute may be specified by any element type that permits use of attributes in the TT Style Namespace; however,
-this attribute applies as a style property only to those element types indicated in the following table.</p><a id="style-property-details-rubyOffset"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>0px</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a> only if the computed value of <a href="#style-attribute-ruby">tts:ruby</a> is <code>container</code>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to this element's font size</td></tr><tr><td><em>Animatable:</em></td><td>continuous</td></tr></tbody></table><p></p><p>If specified, the value of <code>tts:rubyOffset</code> expresses the offset (distance) between padding edge <em>E<sub>1</sub></em> of the inline area
-generated by a ruby text container (explicit or implied) and padding edge <em>E<sub>2</sub></em>  of the inline area generated by a ruby base container (explicit or implied), where
-<em>E<sub>1</sub></em> and <em>E<sub>2</sub></em> are perpendicular to the block progression direction and are (or would be) adjacent in the absence of
-such an offset.</p><p>Negative length expressions are permitted.</p><table border="1" class="ednote" summary="Editorial note: Ruby Offset Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Ruby Offset Example</b></td><td align="right" valign="top">2014-10-02</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add example source and rendering of tts:rubyOffset.</td></tr></table></div><div class="div3">
-<h4><a id="style-attribute-rubyPosition"></a>10.2.31 tts:rubyPosition</h4><p>The <code>tts:rubyPosition</code> attribute is used to specify the position of ruby text in the block progression dimension
-with respect to its associated ruby base.</p><table border="1" class="ednote" summary="Editorial note: Outside Annotations"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Outside Annotations</b></td><td align="right" valign="top">2015-01-14</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add <code>auto</code> and <code>outside</code> values as defined by &lt;emphasisPosition&gt; expressions.</td></tr></table><p>This attribute may be specified by any element type that permits use of attributes in the TT Style Namespace; however,
-this attribute applies as a style property only to those element types indicated in the following table.</p><a id="style-property-details-rubyPosition"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>before</code> |
-<code>after</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>before</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a> only if the computed value of <a href="#style-attribute-ruby">tts:ruby</a> is <code>container</code>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p></p><p>If the value of this attribute is <code>before</code>, then an inline area generated from a ruby text container or ruby text annotation
-is placed before (prior to) the first edge in the block progression dimension of the inline area generated from an associated ruby base container or ruby base annotation.
-If the value is <code>after</code>, then an inline area generated from a ruby text container or ruby text annotation
-is placed after (subsequent to) the second edge in the block progression dimension of the inline area generated from an associated ruby base container or ruby base
-annotation.</p><p>The absolute position of the ruby text container or ruby text annotation is determined
-in accordance to the computed value of the <code>tts:writingMode</code> style property of the region into which the affected content is placed; in particular, the
-mappings defined enumerated by <a href="#rubyPosition-semantics-mapping-table"><b>Table 8-2 – Ruby Position Semantics Mapping by Writing Mode</b></a> apply as further defined by <a href="#cssruby">[CSS Ruby]</a>, §4.1.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>before</code>.</p><a id="rubyPosition-semantics-mapping-table"></a><table class="common"><caption>Table 8-2 – Ruby Position Semantics Mapping by Writing Mode</caption><col width="20%" span="1"><col width="20%" span="1"><col width="20%" span="1"><col width="20%" span="1"><col width="20%" span="1"><col span="1"><tbody><tr><th>tts:rubyPosition</th><th><code>lrtb</code></th><th><code>rltb</code></th><th><code>tbrl</code></th><th><code>tblr</code></th></tr><tr><td><code>before</code></td><td><code>over</code></td><td><code>over</code></td><td><code>right</code></td><td><code>left</code></td></tr><tr><td><code>after</code></td><td><code>under</code></td><td><code>under</code></td><td><code>left</code></td><td><code>right</code></td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Ruby Position Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Ruby Position Example</b></td><td align="right" valign="top">2014-09-20</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add example source and rendering of tts:rubyPosition.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#cssruby">[CSS Ruby]</a>, §4.1, and the examples and example
-renderings shown there apply modulo the mappings defined above.</p></div></div><div class="div3">
-<h4><a id="style-attribute-showBackground"></a>10.2.32 tts:showBackground</h4><p>The <code>tts:showBackground</code> attribute is used to specify
-constraints on when the background color of a region is intended to be
-presented.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-showBackground"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>always</code> |
-<code>whenActive</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>always</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute is <code>always</code>, then the
-background color of a region is always rendered when performing presentation
-processing on a visual medium; if the value is <code>whenActive</code>,
-then the background color of a region is rendered only when some
-content is flowed into the region.</p><p>A region satisfies the <code>whenActive</code> case if (1) it is a
-<a href="#terms-temporally-active-region">temporally active region</a> and (2) content is selected into the region,
-where that content is also <a href="#terms-temporally-active">temporally active</a>.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>always</code>.</p><p>The <code>tts:showBackground</code> style is illustrated by the following example.</p><a id="style-attribute-showBackground-example-1"></a><table class="example"><caption>Example Fragment – Show Background</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:extent="265px 100px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style <span class="strong">tts:showBackground="always"</span>/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:origin="205px 60px"/&gt;
-  &lt;style tts:extent="290px 100px"/&gt;
-  &lt;style tts:backgroundColor="red"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="end"/&gt;
-  &lt;style <span class="strong">tts:showBackground="whenActive"</span>/&gt;
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#smil3">[SMIL 3.0]</a>,
-§ 7.4.2.</p></div></div><div class="div3">
-<h4><a id="style-attribute-textAlign"></a>10.2.33 tts:textAlign</h4><p>The <code>tts:textAlign</code> attribute is used to specify a style property that
-defines how inline areas are aligned within a containing block area in the inline progression
-direction.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textAlign"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>left</code> |
-<code>center</code> |
-<code>right</code> |
-<code>start</code> |
-<code>end</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>start</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>see prose</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>The <code>tts:textAlign</code> attribute is inheritable only on a <a href="#content-vocabulary-p"><code>p</code></a> element. If not
-specified on a <a href="#content-vocabulary-span"><code>span</code></a> element, then the <code>tts:textAlign</code> style property  does not apply to that
-element, rather, normal inline composition and alignment apply.</p><p>If a <code>tts:textAlign</code> attribute is specified on a <a href="#content-vocabulary-span"><code>span</code></a> element,
-then that <a href="#content-vocabulary-span"><code>span</code></a> element must be processed using
-<a href="#terms-inline-block-display">inline block display</a> semantics for the purpose of presentation processing.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <code>tts:textAlign</code> attribute may be used on a <a href="#content-vocabulary-span"><code>span</code></a> element in order
-to force composition using <a href="#terms-inline-block-display">inline block display</a> semantics and to apply a different alignment
-to the resulting nested block area. For example, a paragraph may be composed using center text alignment, while the text content within the paragraph, if
-wrapped in a span, may be composed using left text alignment.</p></div><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>start</code>.</p><p>The <code>tts:textAlign</code> style is illustrated by the following example.</p><a id="style-attribute-textAlign-example-1"></a><table class="example"><caption>Example Fragment – Text Align</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="355px 43px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:textAlign="start"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="355px 43px"/&gt;
-  &lt;style tts:origin="0px 47px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:textAlign="end"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  Beware the Jabberwock, my son!&lt;br/&gt;
-  The jaws that bite, the claws that catch!
-&lt;/p&gt;
-&lt;p region="r2"&gt;
-  Beware the Jubjub bird, and shun&lt;br/&gt;
-  The frumious Bandersnatch!
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-textAlign-example-1-images"></a><table class="example-images"><caption>Example Rendition – Text Align</caption><tbody><tr><td><img src="images/textAlign.png" alt="TTML textAlign style property"></td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Text Align on Span Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Align on Span Example</b></td><td align="right" valign="top">2014-11-29</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of use of tts:textAlign on a span element.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.16.9.</p></div></div><div class="div3">
-<h4><a id="style-attribute-textCombine"></a>10.2.34 tts:textCombine</h4><p>When a vertical writing mode applies, the <code>tts:textCombine</code> attribute is used to specify a style property that
-determines whether and how multiple nominally non-combining characters are combined so that their glyph areas
-consume the nominal bounding box of a single em square. If a horizontal writing mode applies, then this property is ignored
-for the purpose of presentation processing.</p><p>Combination processing may make use of one or more techniques to obtain the goal of visual combination into an em square. For
-example, half-width variant forms may be selected, a ligature may be selected, a smaller font size may be applied, etc. At a minimum, an
-implementation that supports this style property must be able to select half-width variant forms if available.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textCombine"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-<code>all</code> |
-[ <code>digits</code> <a href="#style-value-non-negative-integer">&lt;non-negative-integer&gt;</a>? ]
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If the specified value of this attribute is <code>none</code>, then no combination processing applies.
-If the specified value of this attribute is <code>all</code>, then all affected characters should be combined.
-If the specified value of this attribute is <code>digits</code>, then all affected characters should be combined if they are a sequence of a digits which length is
-equal to or less than a specified count, or two (2) if no count is specified.</p><p>Combination must not cross an element boundary, a bidirectional boundary, or a non-glyph area boundary.</p><p>This attribute has no impact on or interaction with the nominal layout of glyph areas that constitute a Unicode combining character sequence.</p><table border="1" class="ednote" summary="Editorial note: Text Combine Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Combine Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textCombine.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#css3-wm">[CSS Writing Modes]</a>, § 9.1.</p></div></div><div class="div3">
-<h4><a id="style-attribute-textDecoration"></a>10.2.35 tts:textDecoration</h4><p>The <code>tts:textDecoration</code> attribute is used to specify a style property that
-defines a text decoration effect to apply to glyph areas or other inline
-areas that are generated by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textDecoration"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-[ [
-<code>underline</code> |
-<code>noUnderline</code>
-] || [
-<code>lineThrough</code> |
-<code>noLineThrough</code>
-] || [
-<code>overline</code> |
-<code>noOverline</code>
-] ]
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td><a href="#content-vocabulary-span"><code>span</code></a></td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this
-style property, each character child of a <code>p</code> element is
-considered to be enclosed in an anonymous span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>none</code>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The syntax used above in defining the value of this property is based on the
-value component syntax defined in <a href="#css2">[CSS2]</a>, § 1.4.2.1. In essence,
-one or more of the values separated by <code>||</code> may appear in the property
-value in any order, such as <code>"noUnderline overline lineThrough"</code>.</p></div><p>The <code>tts:textDecoration</code> style is illustrated by the following example.</p><a id="style-attribute-textDecoration-example-1"></a><table class="example"><caption>Example Fragment – Text Decoration</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="385px 82px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:padding="5px 2px"/&gt;
-  &lt;style <span class="strong">tts:textDecoration="underline"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  The sea was wet&lt;span <span class="strong">tts:textDecoration="noUnderline"</span>&gt; as &lt;/span&gt;wet
-  &lt;span <span class="strong">tts:textDecoration="noUnderline"</span>&gt;
-    could be,&lt;br/&gt;
-    The sand was dry as dry.&lt;br/&gt;
-    &lt;span <span class="strong">tts:textDecoration="lineThrough"</span>&gt;There weren't any&lt;/span&gt;
-    You &lt;span <span class="strong">tts:textDecoration="lineThrough"</span>&gt;couldn't&lt;/span&gt;
-    could not see a cloud&lt;br/&gt;
-    Because no cloud was in the sky.
-  &lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-textDecoration-example-1-images"></a><table class="example-images"><caption>Example Rendition – Text Decoration</caption><tbody><tr><td><img src="images/textDecoration.png" alt="TTML textDecoration style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.17.4.</p></div></div><div class="div3">
-<h4><a id="style-attribute-textEmphasis"></a>10.2.36 tts:textEmphasis</h4><p>The <code>tts:textEmphasis</code> attribute is used to specify a style property that
-determines whether and how text emphasis marks are presented on affected content.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textEmphasis"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-[
-<a href="#style-value-emphasisStyle">&lt;emphasisStyle&gt;</a> ||
-<a href="#style-value-emphasisColor">&lt;emphasisColor&gt;</a> ||
-<a href="#style-value-emphasisPosition">&lt;emphasisPosition&gt;</a>
-]
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous (color only)</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If the specified value of this attribute is <code>auto</code>, then it must be interpreted as if
-<code>auto</code> were specified for both emphasis style and emphasis position components.</p><p>If no emphasis style is specified,
-then the emphasis style must be interpreted as if a style of <code>auto</code> were specified.
-If no emphasis color is specified,
-then the emphasis color must be interpreted as if a color of <code>current</code> were specified.
-If no emphasis position is specified,
-then the emphasis position must be interpreted as if a position of <code>auto</code> were specified.</p><table border="1" class="ednote" summary="Editorial note: Text Emphasis Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Emphasis Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textEmphasis.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#css3-decoration">[CSS Text Decoration]</a>, § 3.</p></div></div><div class="div3">
-<h4><a id="style-attribute-textOrientation"></a>10.2.37 tts:textOrientation</h4><p>The <code>tts:textOrientation</code> attribute is used to specify a style property that
-defines a text orientation to apply to glyphs that are selected for glyph areas generated
-by content flowed into a region to which a vertical writing mode applies.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textOrientation"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>mixed</code> |
-<code>sideways</code> |
-<code>sidewaysLeft</code> |
-<code>sidewaysRight</code> |
-<code>upright</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>mixed</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If the value of this attribute is <code>mixed</code>, then, in vertical writing modes,
-glyphs from horizontal scripts are set sideways, i.e., 90° clockwise from
-their nominal orientation in horizontal text, while glyphs from vertical scripts are not
-affected.</p><p>If the value of this attribute is <code>sidewaysLeft</code>, then, in vertical writing modes,
-glyphs from horizontal scripts are set sideways with 90° counter-clockwise rotation.</p><p>If the value of this attribute is <code>sidewaysRight</code>, then, in vertical writing modes,
-glyphs from horizontal scripts are set sideways with 90° clockwise rotation.</p><p>If the value of this attribute is <code>sideways</code>, then, in vertical writing modes,
-glyphs from horizontal scripts are set sideways, either 90° clockwise or
-90° counter-clockwise, according to whether the writing mode is
-<code>tbrl</code> or <code>tblr</code>, respectively. Glyphs from vertical scripts are not
-affected.</p><p>If the value of this attribute is <code>upright</code>, then, in vertical writing modes,
-glyphs from horizontal scripts are set upright, i.e., using their
-nominal orientation in horizontal text, while glyphs from vertical scripts are not
-affected. In addition, for purposes of bidirectional processing, this value causes all
-affected characters to be treated as strong left-to-right, i.e., to be treated as if
-a <code>tts:direction</code> of <code>ltr</code> and <code>tts:unicodeOverride</code> of
-<code>override</code> were applied.</p><p>If a vertical writing mode does not apply, then this style property has no effect.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>mixed</code>.</p><p>The <code>tts:textOrientation</code> style is illustrated by the following
-example.</p><table border="1" class="ednote" summary="Editorial note: Text Orientation Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Orientation Example</b></td><td align="right" valign="top">2013-08-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textOrientation.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#css3-wm">[CSS Writing Modes]</a>,
-§ 5.1.</p></div></div><div class="div3">
-<h4><a id="style-attribute-textOutline"></a>10.2.38 tts:textOutline</h4><p>The <code>tts:textOutline</code> attribute is used to specify a style property that
-defines a text outline effect to apply to glyphs that are selected for glyph areas generated
-by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textOutline"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-<a href="#style-value-color">&lt;color&gt;</a>?
-<a href="#style-value-length">&lt;length&gt;</a>
-<a href="#style-value-length">&lt;length&gt;</a>?
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to this element's font size</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The value of this attribute consists of an optional <a href="#style-value-color">&lt;color&gt;</a> term
-followed by one or two <a href="#style-value-length">&lt;length&gt;</a> terms.  If a <em>color</em> term is
-present, then it denotes the outline color; if no <em>color</em> term is
-present, the computed value of the <code>tts:color</code> applies.  The first
-<em>length</em> term denotes the outline thickness and the second length
-term, if present, indicates the blur radius.</p><p>The <a href="#style-value-length">&lt;length&gt;</a> value(s) used to express thickness and blur radius must be non-negative.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When a <a href="#style-value-length">&lt;length&gt;</a> expressed in
-cells is used in a <code>tts:textOutline</code> value,
-the cell's dimension in the block progression dimension applies.
-For example, if text outline thickness is specified as 0.1c, the cell resolution
-is 20 by 10, and the extent of the <a href="#terms-root-container-region">root container region</a> is 640 by 480, then the
-outline thickness will be a nominal 480 / 10 * 0.1 pixels, i.e., 4.8px,
-without taking into account rasterization effects.</p></div><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>none</code>.</p><p>The <code>tts:textOutline</code> style is illustrated by the following
-example.</p><a id="style-attribute-textOutline-example-1"></a><table class="example"><caption>Example Fragment – Text Outline</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:backgroundColor="transparent"/&gt;
-  &lt;style tts:color="yellow"/&gt;
-  &lt;style <span class="strong">tts:textOutline="black 2px 0px"</span>/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="24px"/&gt;
-&lt;/region&gt;
-...
-&lt;p&gt;
-  How doth the little crocodile&lt;br/&gt;
-  Improve its shining tail,&lt;br/&gt;
-  And pour the waters of the Nile&lt;br/&gt;
-  On every golden scale!&lt;br/&gt;
-  How cheerfully he seems to grin,&lt;br/&gt;
-  How neatly spreads his claws,&lt;br/&gt;
-  And welcomes little fishes in,&lt;br/&gt;
-  With gently smiling jaws!
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-textOutline-example-1-images"></a><table class="example-images"><caption>Example Rendition – Text Outline</caption><tbody><tr><td><img src="images/textOutline.png" alt="textOutline style property"></td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-attribute-textShadow"></a>10.2.39 tts:textShadow</h4><p>The <code>tts:textShadow</code> attribute is used to specify a style property that
-defines one or more text shadow decorations to apply to glyphs that are selected for glyph areas generated
-by content flowed into a region.</p><p>If both <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a> and <code>tts:textShadow</code> attributes
-are specified on an element and <code>tts:textShadow</code> is a supported property,
-then the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a> attribute must be ignored for the purpose of presentation processing.</p><p>If multiple text shadows apply, then they are drawn in the specified order immediately prior to drawing the glyph area to which they apply.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-textShadow"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-[ <a href="#style-value-shadow">&lt;shadow&gt;</a> ]#
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to this element's font size</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>none</code>.</p><table border="1" class="ednote" summary="Editorial note: Text Shadow Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Shadow Example</b></td><td align="right" valign="top">2015-01-08</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textShadow.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
-that defined by <a href="#css3-decoration">[CSS Text Decoration]</a>, § 4.</p></div></div><div class="div3">
-<h4><a id="style-attribute-unicodeBidi"></a>10.2.40 tts:unicodeBidi</h4><p>The <code>tts:unicodeBidi</code> attribute is used to specify a style property that
-defines a directional embedding or override according to
-the Unicode bidirectional algorithm.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-unicodeBidi"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<code>embed</code> |
-<code>bidiOverride</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>normal</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>normal</code>.</p><p>The <code>tts:unicodeBidi</code> style is illustrated by the following example.</p><a id="style-attribute-unicodeBidi-example-1"></a><table class="example"><caption>Example Fragment – Unicode Bidirectionality</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="265px 84px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  Little birds are playing&lt;br/&gt;
-  Bagpipes on the shore,&lt;br/&gt;
-  &lt;span <span class="strong">tts:unicodeBidi="bidiOverride"</span> tts:direction="rtl"&gt;where the tourists snore.&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-unicodeBidi-example-1-images"></a><table class="example-images"><caption>Example Rendition – Unicode Bidirectionality</caption><tbody><tr><td>
-<img src="images/unicodeBidi.png" alt="TTML unicodeBidi style property">
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.29.6.</p></div></div><div class="div3">
-<h4><a id="style-attribute-visibility"></a>10.2.41 tts:visibility</h4><p>The <code>tts:visibility</code> attribute is used to specify a style property that
-defines whether generated areas are visible or not when rendered on a visual
-presentation medium.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-visibility"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>visible</code> |
-<code>hidden</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>visible</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The <code>tts:visibility</code> style has no affect on content layout or
-composition, but merely determines whether composed content is visible or not.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>visible</code>.</p><p>The <code>tts:visibility</code> style is illustrated by the following example.</p><a id="style-attribute-visibility-example-1"></a><table class="example"><caption>Example Fragment – Visibility</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="398px 121px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1" dur="4s"&gt;
-  &lt;span <span class="strong">tts:visibility="hidden"</span>&gt;
-    &lt;set begin="1s" <span class="strong">tts:visibility="visible"</span>/&gt;
-    Curiouser
-  &lt;/span&gt;
-  &lt;span <span class="strong">tts:visibility="hidden"</span>&gt;
-    &lt;set begin="2s" <span class="strong">tts:visibility="visible"</span>/&gt;
-    and
-  &lt;/span&gt;
-  &lt;span <span class="strong">tts:visibility="hidden"</span>&gt;
-    &lt;set begin="3s" <span class="strong">tts:visibility="visible"</span>/&gt;
-    curiouser!
-  &lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-visibility-example-1-images"></a><table class="example-images"><caption>Example Rendition – Visibility</caption><tbody><tr><td>
-<img src="images/visibility_0.png" alt="TTML visibility style property - [0,1)">
-</td></tr><tr><td>
-<img src="images/visibility_1.png" alt="TTML visibility style property - [1,2)">
-</td></tr><tr><td>
-<img src="images/visibility_2.png" alt="TTML visibility style property - [2,3)">
-</td></tr><tr><td>
-<img src="images/visibility_3.png" alt="TTML visibility style property - [3,4)">
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.30.17.</p></div></div><div class="div3">
-<h4><a id="style-attribute-width"></a>10.2.42 tts:width</h4><p>The <code>tts:width</code> attribute is used to specify the
-<em>width</em> of an area generated by content flowed into a region.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The term <em>width</em> is interpreted in a writing mode relative manner
-such that <em>width</em> always corresponds to a measure in the inline
-progression direction. Therefore, in horizontal writing modes, <em>width</em> expresses a horizontal measure,
-while, in vertical writing mode, <em>width</em> expresses a vertical measure,
-where horizontal and vertical are always interpreted in an absolute sense.</p></div><p>If a <code>tts:width</code> attribute is specified on a <a href="#content-vocabulary-span"><code>span</code></a> element,
-then that <a href="#content-vocabulary-span"><code>span</code></a> element must be processed using
-<a href="#terms-inline-block-display">inline block display</a> semantics for the purpose of presentation processing.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-width"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-measure">&lt;measure&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>,
-<a href="#embedded-content-vocabulary-image"><code>image</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>see prose</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If a <a href="#style-value-measure">&lt;measure&gt;</a> is expressed as a <a href="#style-value-length">&lt;length&gt;</a> value, then it must be non-negative.</p><p>The <code>tts:width</code> style is illustrated by the following example.</p><table border="1" class="ednote" summary="Editorial note: Width Percentage"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Width Percentage</b></td><td align="right" valign="top">2014-11-29</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Specify resolution of percentage value.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: Width Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Width Example</b></td><td align="right" valign="top">2014-11-29</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:width.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.15.14, and <a href="#css3-box">[CSS Box Model]</a>, § 9</p></div></div><div class="div3">
-<h4><a id="style-attribute-wrapOption"></a>10.2.43 tts:wrapOption</h4><p>The <code>tts:wrapOption</code> attribute is used to specify a style property that
-defines whether or not automatic line wrapping (breaking) applies within the context of
-the affected element.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-wrapOption"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>wrap</code> |
-<code>noWrap</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>wrap</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>wrap</code>.</p><p>The <code>tts:wrapOption</code> style is illustrated by the following example.</p><a id="style-attribute-wrapOption-example-1"></a><table class="example"><caption>Example Fragment – Wrap Option</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="192px 117px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:overflow="hidden"/&gt;
-  &lt;style <span class="strong">tts:wrapOption="noWrap"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p&gt;
-  I'll tell thee everything I can:&lt;br/&gt;
-  There's little to relate.&lt;br/&gt;
-  I saw an aged aged man,&lt;br/&gt;
-  A-sitting on a gate.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-wrapOption-example-1-images"></a><table class="example-images"><caption>Example Rendition – Wrap Option</caption><tbody><tr><td><img src="images/wrapOption.png" alt="TTML wrapOption style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.16.13.</p></div></div><div class="div3">
-<h4><a id="style-attribute-writingMode"></a>10.2.44 tts:writingMode</h4><p>The <code>tts:writingMode</code> attribute is used to specify a style property that
-defines the block and inline progression directions to be used for the purpose of
-stacking block and inline areas within a region area.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-writingMode"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>lrtb</code> |
-<code>rltb</code> |
-<code>tbrl</code> |
-<code>tblr</code> |
-<code>lr</code> |
-<code>rl</code> |
-<code>tb</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>lrtb</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>lrtb</code>.</p><p>The <code>tts:writingMode</code> style is illustrated by the following example.</p><a id="style-attribute-writingMode-example-1"></a><table class="example"><caption>Example Fragment – Writing Mode</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="50px 570px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:padding="10px 3px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:writingMode="tbrl"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="310px 50px"/&gt;
-  &lt;style tts:origin="70px 120px"/&gt;
-  &lt;style tts:padding="10px 3px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:writingMode="rltb"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  I sometimes dig for buttered rolls,&lt;br/&gt;
-  Or set limed twigs for crabs:
-&lt;/p&gt;
-&lt;p region="r2" tts:direction="rtl" tts:unicodeBidi="bidiOverride"&gt;
-  I sometimes search the grassy knolls for the wheels of Hansom-cabs.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-writingMode-example-1-images"></a><table class="example-images"><caption>Example Rendition – Writing Mode</caption><tbody><tr><td><img src="images/writingMode.png" alt="TTML writingMode style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the second paragraph in the above example that targets region
-<code>r2</code>, the <code>tts:unicodeBidi</code> and
-<code>tts:direction</code> properties are set to
-<code>bidiOverride</code> and <code>rtl</code>, respectively, in order
-to override the normally left-to-right directionality of characters in
-the Latin script.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.29.7.</p></div></div><div class="div3">
-<h4><a id="style-attribute-zIndex"></a>10.2.45 tts:zIndex</h4><p>The <code>tts:zIndex</code> attribute is used to specify a style property that
-defines the front-to-back ordering of region areas in the case that they overlap.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><a id="style-property-details-zIndex"></a><table class="common"><col width="25%" span="1"><col span="1"><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<a href="#style-value-integer">&lt;integer&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous (over integral values only)</td></tr></tbody></table><p>If two areas are associated with the same Z-index value, then, if those areas
-overlap in space, the area(s) generated by lexically subsequent elements must be
-rendered over area(s) generated by lexically prior elements, where lexical
-order is defined as the postorder traversal of a <a href="#terms-document-instance">document instance</a>.</p><p>The semantics of the value <code>auto</code> are those defined by
-<a href="#xsl11">[XSL 1.1]</a>, § 7.30.18, where the <code>tt</code> element
-is considered to establish the root stacking context.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed z-index and the supported z-index is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value least distant from 0, i.e., closest to the base stack level of the current stacking context, is used.</p></div><p>The <code>tts:zIndex</code> style is illustrated by the following example.</p><a id="style-attribute-zIndex-example-1"></a><table class="example"><caption>Example Fragment – Z Index</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:zIndex="0"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:origin="100px 60px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="red"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:textAlign="end"/&gt;
-  &lt;style <span class="strong">tts:zIndex="1"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r3"&gt;
-  &lt;style tts:origin="0px 120px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:zIndex="2"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r4"&gt;
-  &lt;style tts:origin="100px 180px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="red"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:textAlign="end"/&gt;
-  &lt;style <span class="strong">tts:zIndex="3"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  I passed by his garden, and marked, with one eye,&lt;br/&gt;
-  How the Owl and the Panther were sharing a pie.
-&lt;/p&gt;
-&lt;p region="r2"&gt;
-  The Panther took pie-crust, and gravy, and meat,&lt;br/&gt;
-  While the Owl had the dish as its share of the treat.
-&lt;/p&gt;
-&lt;p region="r3"&gt;
-  When the pie was all finished, the Owl, as a boon,&lt;br/&gt;
-  Was kindly permitted to pocket the spoon:
-&lt;/p&gt;
-&lt;p region="r4"&gt;
-  While the Panther received knife and fork&lt;br/&gt;
-  with a growl,&lt;br/&gt;
-  And concluded the banquet by...
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><p></p><a id="style-attribute-zIndex-example-1-images"></a><table class="example-images"><caption>Example Rendition – Z Index</caption><tbody><tr><td><img src="images/zIndex.png" alt="TTML zIndex style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property
-represented by this attribute are based upon that defined by <a href="#xsl11">[XSL 1.1]</a>,
-§ 7.30.18.</p></div></div></div><div class="div2">
-<h3><a id="styling-style-value-expressions"></a>10.3 Styling Value Expressions</h3><p>Style property values include the use of the following expressions:</p><ul><li><p><a href="#style-value-alpha"><b>10.3.1 &lt;alpha&gt;</b></a></p></li><li><p><a href="#style-value-borderColor"><b>10.3.2 &lt;borderColor&gt;</b></a></p></li><li><p><a href="#style-value-borderStyle"><b>10.3.3 &lt;borderStyle&gt;</b></a></p></li><li><p><a href="#style-value-borderWidth"><b>10.3.4 &lt;borderWidth&gt;</b></a></p></li><li><p><a href="#style-value-color"><b>10.3.5 &lt;color&gt;</b></a></p></li><li><p><a href="#style-value-digit"><b>10.3.6 &lt;digit&gt;</b></a></p></li><li><p><a href="#style-value-emphasisColor"><b>10.3.7 &lt;emphasisColor&gt;</b></a></p></li><li><p><a href="#style-value-emphasisStyle"><b>10.3.8 &lt;emphasisStyle&gt;</b></a></p></li><li><p><a href="#style-value-emphasisPosition"><b>10.3.9 &lt;emphasisPosition&gt;</b></a></p></li><li><p><a href="#style-value-familyName"><b>10.3.10 &lt;familyName&gt;</b></a></p></li><li><p><a href="#style-value-genericFamilyName"><b>10.3.11 &lt;genericFamilyName&gt;</b></a></p></li><li><p><a href="#style-value-hexDigit"><b>10.3.12 &lt;hexDigit&gt;</b></a></p></li><li><p><a href="#style-value-integer"><b>10.3.13 &lt;integer&gt;</b></a></p></li><li><p><a href="#style-value-length"><b>10.3.14 &lt;length&gt;</b></a></p></li><li><p><a href="#style-value-measure"><b>10.3.15 &lt;measure&gt;</b></a></p></li><li><p><a href="#style-value-namedColor"><b>10.3.16 &lt;namedColor&gt;</b></a></p></li><li><p><a href="#style-value-non-negative-integer"><b>10.3.17 &lt;non-negative-integer&gt;</b></a></p></li><li><p><a href="#style-value-number"><b>10.3.18 &lt;number&gt;</b></a></p></li><li><p><a href="#style-value-percentage"><b>10.3.19 &lt;percentage&gt;</b></a></p></li><li><p><a href="#style-value-position"><b>10.3.20 &lt;position&gt;</b></a></p></li><li><p><a href="#style-value-shadow"><b>10.3.21 &lt;shadow&gt;</b></a></p></li></ul><p>In the syntax representations defined in this section, no
-linear whitespace (LWSP) is implied or permitted between tokens
-unless explicitly specified.</p><div class="div3">
-<h4><a id="style-value-alpha"></a>10.3.1 &lt;alpha&gt;</h4><p>An &lt;alpha&gt; expression is used to express an opacity value,
-where	0 means fully transparent and 1 means fully opaque.</p><a id="alpha-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;alpha&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;alpha&gt;
-  : <em>float</em>
-</pre></div>
-</td></tr></tbody></table><p>In the above syntax representation, the syntactic element
-<em><code>float</code></em> must adhere to the lexical
-representation defined by <a href="#xsd-2">[XML Schema Part 2]</a>&nbsp;§
-3.2.4.1. If the value represented is less than 0.0,
-then it must be interpreted as equal to 0.0; similarly, if the value
-represented is greater than 1.0, then it must be interpreted as
-1.0. The value NaN must be interpreted as 0.0.</p><p>A specified value for &lt;alpha&gt; should not be <code>NaN</code>,
-less than 0, or greater than 1.</p><p>If a <a href="#terms-presentation-processor">presentation processor</a> does not support a specific,
-valid opacity value, then it must interpret it as being equal to the
-closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed opacity and the supported opacity is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value most distant from 0, i.e., the greatest opacity, is used.</p></div></div><div class="div3">
-<h4><a id="style-value-borderColor"></a>10.3.2 &lt;borderColor&gt;</h4><p>A &lt;borderColor&gt; expression is used to express the color of one
-or more borders.</p><a id="borderColor-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;borderColor&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;borderColor&gt;
-  : <a href="#style-value-color">&lt;color&gt;</a>
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-borderStyle"></a>10.3.3 &lt;borderStyle&gt;</h4><p>A &lt;borderStyle&gt; expression is used to express the style of one
-or more borders.</p><a id="borderStyle-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;borderStyle&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;borderStyle&gt;
-  : none
-  | dotted
-  | dashed
-  | solid
-  | double
-</pre></div>
-</td></tr></tbody></table><p>The interpretation of <code>dotted</code>, <code>dashed</code>, and <code>double</code> are considered
-to be implementation dependent.</p><p>If an implementation does not recognize or otherwise distinguish one of these border style values, then
-it must be interpreted as if a style of <code>solid</code> were specified; as such, an implementation that
-supports borders must minimally support the <code>solid</code> value.</p></div><div class="div3">
-<h4><a id="style-value-borderWidth"></a>10.3.4 &lt;borderWidth&gt;</h4><p>A &lt;borderWidth&gt; expression is used to express the width of one
-or more borders.</p><a id="borderWidth-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;borderWidth&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;borderWidth&gt;
-  : thin
-  | medium
-  | thick
-  | <a href="#style-value-length">&lt;length&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>The interpretation of <code>thin</code>, <code>medium</code>, and <code>thick</code> are considered
-to be implementation dependent; however, the resolved lengths of these widths must adhere to the following
-constraints: width(thin) &lt; width(medium); width(medium) &lt; width(thick).</p><p>If a border width is expressed as a <a href="#style-value-length">&lt;length&gt;</a>,
-then it must not take the form of a percentage value; i.e., it must take the form of a scalar value.</p></div><div class="div3">
-<h4><a id="style-value-color"></a>10.3.5 &lt;color&gt;</h4><p>A &lt;color&gt; expression is used to specify a named color, exact RGB color triple,
-or exact RGBA color tuple, where the alpha component, if expressed,
-is maximum (255) at 100% opacity
-and minimum (0) at 0% opacity, and where the applicable color space is
-defined by <a href="#srgb">[SRGB]</a>.</p><a id="color-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;color&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;color&gt;
-  : "#" rrggbb
-  | "#" rrggbbaa
-  | "rgb" "(" r-value "," g-value "," b-value ")"
-  | "rgba" "(" r-value "," g-value "," b-value "," a-value ")"
-  | <a href="#style-value-namedColor">&lt;namedColor&gt;</a>
-
-rrggbb
-  :  <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a>{6}
-
-rrggbbaa
-  :  <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a>{8}
-
-r-value | g-value | b-value | a-value
-  : component-value
-
-component-value
-  : non-negative-integer                    // valid range: [0,255]
-
-non-negative-integer
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table><p>When expressing RGB component values, these values are considered
-to <span class="strong">not</span> be premultiplied by alpha.</p><p>For the purpose of performing presentation processing such that
-non-opaque or non-transparent alpha or opacity values apply, then the
-semantics of compositing functions are defined with respect to the use of
-the <a href="#srgb">[SRGB]</a> color space for both inputs and outputs of
-the composition function.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of <a href="#srgb">[SRGB]</a> for the stated semantics of
-composition is not meant to prevent an actual processor from using some
-other color space either for internal or external purposes. For
-example, a <a href="#terms-presentation-processor">presentation processor</a> may ultimately convert the SRGB values
-used here to the YUV color space for rendition on a television device.</p></div><p>If a <a href="#terms-presentation-processor">presentation processor</a> does not support a specific,
-valid color or alpha value, then it must interpret it as being equal
-to the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
-the computed color and alpha and the supported color and alpha in the RGB color space is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value least distant from opaque black <code>rgb(0,0,0,255)</code>, i.e., the closest to opaque black, is used.</p></div></div><div class="div3">
-<h4><a id="style-value-digit"></a>10.3.6 &lt;digit&gt;</h4><p>A &lt;digit&gt; is used to express integers and other types of numbers or tokens.</p><a id="digit-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;digit&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;digit&gt;
-  : "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-emphasisColor"></a>10.3.7 &lt;emphasisColor&gt;</h4><p>An &lt;emphasisColor&gt; expression is used to express the color of text
-emphasis marks.</p><a id="emphasisColor-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;emphasisColor&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;emphasisColor&gt;
-  : current
-  | <a href="#style-value-color">&lt;color&gt;</a>
-</pre></div>
-</td></tr></tbody></table><dl><dt class="label"><code>current</code></dt><dd><p>Equivalent to the computed value of <a href="#style-attribute-color"><code>tts:color</code></a> of the affected text.</p></dd><dt class="label"><a href="#style-value-color">&lt;color&gt;</a></dt><dd><p>The specified color.</p></dd></dl><p>If an implementation does not recognize or otherwise distinguish emphasis color value, then
-it must be interpreted as if a style of <code>current</code> were specified; as such, an implementation that
-supports text emphasis marks must minimally support the <code>current</code> value.</p></div><div class="div3">
-<h4><a id="style-value-emphasisStyle"></a>10.3.8 &lt;emphasisStyle&gt;</h4><p>An &lt;emphasisStyle&gt; expression is used to express the style of text
-emphasis marks.</p><a id="emphasisStyle-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;emphasisStyle&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;emphasisStyle&gt;
-  : none
-  | auto 
-  | [ filled | open ] || [ circle | dot | sesame ]
-  | <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>The semantics of text emphasis style values are defined as follows:</p><dl><dt class="label"><code>none</code></dt><dd><p>No text emphasis mark.</p></dd><dt class="label"><code>auto</code></dt><dd><p>If a vertical writing mode applies, then equivalent to <code>filled sesame</code>; otherwise,
-equivalent to <code>filled circle</code>.</p></dd><dt class="label"><code>filled</code></dt><dd><p>Emphasis mark is filled with emphasis color.</p></dd><dt class="label"><code>open</code></dt><dd><p>Emphasis mark is not filled, i.e., its outline is stroked with the emphasis color, but it is not filled.</p></dd><dt class="label"><code>circle</code></dt><dd><p>Emphasis mark is a circle. If filled, then equivalent to U+25CF '●'; if open, then equivalent to U+25CB '○'</p></dd><dt class="label"><code>dot</code></dt><dd><p>Emphasis mark is a dot. If filled, then equivalent to U+2022 '•'; if open, then equivalent to U+25E6 '◦'</p></dd><dt class="label"><code>sesame</code></dt><dd><p>Emphasis mark is a sesame. If filled, then equivalent to U+FE45 '﹅'; if open, then equivalent to U+FE46 '﹆'</p></dd><dt class="label"><a href="#content-value-quoted-string">&lt;quoted-string&gt;</a></dt><dd><p>Emphasis mark is the first grapheme cluster of string, with remainder of string ignored.</p></dd></dl><p>If only <code>filled</code> or <code>open</code> is specified, then it is equivalent to <code>filled circle</code> and <code>open circle</code>, respectively.</p><p>If only <code>circle</code>, <code>dot</code>, or <code>sesame</code> is specified, then it is equivalent to <code>filled circle</code>, <code>filled dot</code>, and
-<code>filled sesame</code>, respectively.</p><p>If an implementation does not recognize or otherwise distinguish an emphasis style value, then
-it must be interpreted as if a style of <code>auto</code> were specified; as such, an implementation that
-supports text emphasis marks must minimally support the <code>auto</code> value.</p></div><div class="div3">
-<h4><a id="style-value-emphasisPosition"></a>10.3.9 &lt;emphasisPosition&gt;</h4><p>An &lt;emphasisPosition&gt; expression is used to express the position of text
-emphasis marks.</p><a id="emphasisPosition-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;emphasisPosition&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;emphasisPosition&gt;
-  : auto
-  | before
-  | after
-  | outside
-</pre></div>
-</td></tr></tbody></table><dl><dt class="label"><code>auto</code></dt><dd><p>If the containing block area consists of exactly two line areas, then equivalent to <code>outside</code>; otherwise,
-equivalent to <code>before</code>.</p></dd><dt class="label"><code>before</code></dt><dd><p>Towards the before edge of the affected glyph areas. If a horizontal writing mode applies, then this is towards the
-top of the glyph areas. If a vertical writing mode applies, then this is either towards the right or left of the glyph
-areas, according to whether <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a> resolves to
-<code>tbrl</code> or <code>tblr</code>, respectively.</p></dd><dt class="label"><code>after</code></dt><dd><p>Towards the after edge of the affected glyph areas. If a horizontal writing mode applies, then this is towards the
-bottom of the glyph areas. If a vertical writing mode applies, then this is either towards the left or right of the glyph
-areas, according to whether <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a> resolves to
-<code>tbrl</code> or <code>tblr</code>, respectively.</p></dd><dt class="label"><code>outside</code></dt><dd><p>Equivalent to <code>before</code> for all but the last affected line area; otherwise, equivalent to <code>after</code>
-for the last affected line area.</p></dd></dl><p>If an implementation does not recognize or otherwise distinguish an emphasis position value, then
-it must be interpreted as if a position of <code>auto</code> were specified; as such, an implementation that
-supports text emphasis marks must minimally support the <code>auto</code> value.</p></div><div class="div3">
-<h4><a id="style-value-familyName"></a>10.3.10 &lt;familyName&gt;</h4><p>A &lt;familyName&gt; expression specifies a font family name.</p><a id="familyName-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;familyName&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;familyName&gt;
-  : unquoted-string
-  | <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
-
-unquoted-string
-  : identifier ( lwsp identifier )*
-
-lwsp
-  : ( ' ' | '\t' | '\n' | '\r' )+
-
-identifier
-  : [-]? identifier-start identifier-following*
-
-identifier-start
-  : [_a-zA-Z]
-  | non-ascii-or-c1
-  | escape
-
-identifier-following
-  : [_a-zA-Z0-9-]
-  | non-ascii-or-c1
-  | escape
-
-non-ascii-or-c1
-  : [^\0-\237]
-
-escape
-  : '\\' <em>char</em>
-</pre></div>
-
-</td></tr></tbody></table><p>In addition to adhering to the syntax rules specified above, the following semantic rules apply:</p><ul><li><p>the semantic value of a &lt;familyName&gt; expression is the semantic value of its <code>unquoted-string</code> or <code>quoted-string</code>
-non-terminal, according to whichever applies;</p></li><li><p>the semantic value of an <code>unquoted-string</code> non-terminal is a pair <code>&lt;</code><em>quoted</em>, <em>content</em><code>&gt;</code>,
-where <em>quoted</em> is a boolean <code>false</code>, and
-where <em>content</em> is the result of appending the value of each <code>identifier</code>
-non-terminal, in lexical order, where the value of each identifier is preceded by a single SPACE (U+0020) character if it is not the first
-identifier;</p></li><li><p>the semantic value of a <code>quoted-string</code> non-terminal is a pair <code>&lt;</code><em>quoted</em>, <em>content</em><code>&gt;</code>,
-where <em>quoted</em> is a boolean <code>true</code>, and
-where <em>content</em> is the unquoted content of the quoted string, i.e., the sequence of characters between the delimiting quotes.</p></li><li><p>the semantic value of an <code>escape</code> non-terminal is the value of the escaped <code>char</code>;</p></li><li><p>a &lt;familyName&gt; that takes the form of an <code>unquoted-string</code> that contains an <code>identifier</code> that
-starts with two <code>-</code> HYPHEN-MINUS (U+002D) characters must be considered to be invalid;</p></li><li><p>a &lt;familyName&gt; that takes the form of an <code>unquoted-string</code> that contains a single <code>identifier</code> that
-matches (by case sensitive comparison) a &lt;genericFamilyName&gt; must be interpreted as that &lt;genericFamilyName&gt;;</p></li><li><p>a &lt;familyName&gt; that takes the form of a <code>quoted-string</code> whose content (unquoted value)
-matches (by case sensitive comparison) a &lt;genericFamilyName&gt; must not be interpreted as that &lt;genericFamilyName&gt;, but as
-the actual name of a non-generic font family.</p></li><li><p>The syntactic element <em><code>char</code></em> is to be interpreted according
-to the <code>Char</code> production defined by <a href="#xml10">[XML 1.0]</a>&nbsp;§2.2.</p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>The <code>{unicode}</code> escape mechanism defined by <a href="#css2">[CSS2]</a>&nbsp;§4.1.1
-is not supported by this syntax; rather, authors are expected to either (1) directly encode the character
-using the document encoding or (2) use an XML character reference according to
-<a href="#xml10">[XML 1.0]</a>&nbsp;§4.1. When a syntactically significant character needs to be used
-without its normal syntactic interpretation, it may be be escaped using the backslash
-(reverse solidus) <code>escape</code> non-terminal specified above.</p><p>When using the backslash (reverse solidus) <code>escape</code> non-terminal, the above syntax does
-not place any restriction on what character may be escaped, e.g., <code>\\[\n\r\f0-9a-f]</code> are
-permitted. If one of these latter escapes appears in a &lt;familyName&gt; expression, then it will
-need to be converted to a <code>{unicode}</code> escape if it is to be used with a standard XSL-FO
-or CSS parser. In particular, a backslash followed by a newline is ignored by CSS, while it is not
-ignored by the above syntax. Such an unignored escaped newline would need to be represented using
-an equivalent <code>{unicode}</code> escape, such as <code>\a</code>, to order to express in CSS.</p></div></div><div class="div3">
-<h4><a id="style-value-genericFamilyName"></a>10.3.11 &lt;genericFamilyName&gt;</h4><p>A &lt;genericFamilyName&gt; expression specifies a font family using a general
-token that indicates a class of font families.</p><p>The resolution of a generic family name to a concrete font instance is considered to
-be implementation dependent, both in the case of content authoring and content interpretation.</p><a id="genericFamilyName-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;genericFamilyName&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;genericFamilyName&gt;
-  : "default"
-  | "monospace"
-  | "sansSerif"
-  | "serif"
-  | "monospaceSansSerif"
-  | "monospaceSerif"
-  | "proportionalSansSerif"
-  | "proportionalSerif"
-</pre></div>
-</td></tr></tbody></table><p>The mapping between a generic (font) family name and an actual font is not
-determined by this specification; however, the
-distinction of monospace versus proportional and serif versus sans-serif
-should be maintained if possible when performing presentation.</p><p>If a generic (font) family name of <code>monospace</code> is specified,
-then it may be interpreted as equivalent to either <code>monospaceSansSerif</code>
-or <code>monospaceSerif</code>. The generic family names <code>sansSerif</code>
-and <code>serif</code> are to be interpreted as equivalent to <code>proportionalSansSerif</code>
-and <code>proportionalSerif</code>, respectively.</p><p>If the generic family name <code>default</code> is specified (or implied by
-an initial value), then its typographic characteristics are considered to be implementation
-dependent; however, it is recommended that this default font family be mapped to
-an monospaced, sans-serif font.</p></div><div class="div3">
-<h4><a id="style-value-hexDigit"></a>10.3.12 &lt;hexDigit&gt;</h4><p>A &lt;hexDigit&gt; is used to express integers and other types of numbers or tokens
-that employ base 16 arithmetic.</p><p>For the purpose of parsing, a distinction must not be made between lower and upper case.</p><a id="hexDigit-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;hexDigit&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;hexDigit&gt;
-  : <a href="#style-value-digit">&lt;digit&gt;</a>
-  | "a" | "b" | "c" | "d" | "e" | "f"
-  | "A" | "B" | "C" | "D" | "E" | "F"
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-integer"></a>10.3.13 &lt;integer&gt;</h4><p>An &lt;integer&gt; expression is used to express an arbitrary, signed integral value.</p><a id="integer-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;integer&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;integer&gt;
-  : ( "+" | "-" )? <a href="#style-value-non-negative-integer">&lt;non-negative-integer&gt;</a>
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-length"></a>10.3.14 &lt;length&gt;</h4><p>A &lt;length&gt; expression is used to express either a coordinate component of point
-in a cartesian space or a distance between two points in a cartesian space.</p><a id="length-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;length&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;length&gt;
-  : scalar
-  | <a href="#style-value-percentage">&lt;percentage&gt;</a>
-
-scalar
-  : <a href="#style-value-percentage">&lt;number&gt;</a> units
-
-units
-  : "px"
-  | "em"
-  | "c"                                     // abbreviation of "cell"
-  | "vw"
-  | "vh"
-</pre></div>
-</td></tr></tbody></table><p>It is an error to omit the units component of a scalar length
-value.</p><p>The semantics of
-the unit of measure <code>px</code> (pixel) 
-are as defined by <a href="#xsl11">[XSL 1.1]</a>, § 5.9.13.</p><div class="issue"><p class="prefix"><a id="issue-179"></a><b>Issue (issue-179):</b></p><p class="prefix"><b>Definition of Pixel</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/179">http://www.w3.org/AudioVideo/TT/tracker/issues/179</a></p><p>Replace unworkable (and unadopted) definition of pixel with an appropriate definition based on units of some viewport coordinate space.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>When specified relative to a font whose size is expressed as a single length
-measure or as two length measures of equal length, the unit of measure <code>em</code> is considered to be
-identical to that defined by <a href="#xsl11">[XSL 1.1]</a>, § 5.9.13;
-however, when specified relative to a font whose size is expressed as
-two length measures of non-equal lengths, then one <code>em</code> is
-equal to the inline progression dimension of the anamorphically
-scaled font when used to specify lengths in the inline progression
-direction and equal to the block progression dimension of the scaled
-font when used to specify lengths in the block progression direction.</p><p>The semantics of the unit of measure <code>c</code> (cell) are
-defined by the parameter <a href="#parameter-attribute-cellResolution"><b>7.2.1 ttp:cellResolution</b></a>.</p><p>The units of measure <code>vw</code> and <code>vh</code> are defined as
-one percent (1%) of the width and height of the <a href="#terms-root-container-region">root container region</a>, respectively.
-For example, the length <code>25vw</code> is interpreted as 25% of the width of
-the <a href="#terms-root-container-region">root container region</a>.</p></div><div class="div3">
-<h4><a id="style-value-measure"></a>10.3.15 &lt;measure&gt;</h4><p>A &lt;measure&gt; value expresses a distance used to measure an allocation
-dimension in either the inline progression direction or the block progression direction, where
-the direction that applies is determined by the context of use.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The terms <em>width</em> and <em>height</em> are interpreted in a writing mode relative manner
-such that <em>width</em> always corresponds to a measure in the inline
-progression direction and <em>height</em> always corresponds to a measure in the block progression direction.
-Therefore, in horizontal writing modes, <em>width</em> expresses a horizontal measure
-and <em>height</em> expresses a vertical measure, while, in vertical writing mode, <em>width</em> expresses a vertical measure
-and <em>height</em> expresses a horizontal measure, where horizontal and vertical are always interpreted in an absolute sense.</p></div><a id="measure-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;measure&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;measure&gt;
-  : auto
-  | available
-  | fitContent
-  | maxContent
-  | minContent
-  | <a href="#style-value-length">&lt;length&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>The semantics of measure values are defined as follows:</p><dl><dt class="label"><code>auto</code></dt><dd><p>As determined by <a href="#semantics-style-automatic-measure-calculation"><b>10.4.5 Automatic Measure Calculation</b></a>.</p></dd><dt class="label"><code>available</code></dt><dd><p>For width in a horizontal writing mode, the numeric value equal to the width of the parent containing block's width less
-the current element's combined border and padding width.
-For height in a horizontal writing mode, the numeric value equal to the height of the parent containing block's height less
-the current element's combined border and padding height.</p><p>For vertical writing mode, the sense of width and height is reversed.</p></dd><dt class="label"><code>fitContent</code></dt><dd><p>A numeric value equal to the maximum of the values of (1) <code>minContent</code> and (2) the minimum of values of <code>maxContent</code> and <code>available</code>.</p></dd><dt class="label"><code>maxContent</code></dt><dd><p>For width in a horizontal writing mode, the maximum numeric value that encloses all of the element's content such that lines are broken only at
-hard, i.e., mandatory, break points, even if that means overflowing the parent's width.</p><p>For height in a horizontal writing mode, the maximum numeric value that encloses all of the element's content such that lines are broken at
-all possible line break positions, i.e., both hard (mandatory) and soft (optional) break points.</p><p>For vertical writing mode, the sense of width and height is reversed.</p></dd><dt class="label"><code>minContent</code></dt><dd><p>For width in a horizontal writing mode, the minimum numeric value that encloses all of the element's content such that lines are broken at
-all possible line break positions, i.e., both hard (mandatory) and soft (optional) break points.</p><p>For height in a horizontal writing mode, the minimum numeric value that encloses all of the element's content such that lines are broken only at
-hard, i.e., mandatory, break points, even if that means overflowing the parent's width.</p><p>For vertical writing mode, the sense of width and height is reversed.</p></dd><dt class="label"><code><a href="#style-value-length">&lt;length&gt;</a></code></dt><dd><p>A non-negative numeric value expressed as a scalar or percentage.</p></dd></dl></div><div class="div3">
-<h4><a id="style-value-namedColor"></a>10.3.16 &lt;namedColor&gt;</h4><p>A &lt;namedColor&gt; is used to express an RGBA color with a convenient name, and where the applicable color space is
-defined by <a href="#srgb">[SRGB]</a>.</p><p>For the purpose of parsing, a distinction must not be made between lower and upper case.</p><a id="namedColor-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;namedColor&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;namedColor&gt;
-  : "transparent"                           // #00000000
-  | "black"                                 // #000000ff
-  | "silver"                                // #c0c0c0ff
-  | "gray"                                  // #808080ff
-  | "white"                                 // #ffffffff
-  | "maroon"                                // #800000ff
-  | "red"                                   // #ff0000ff
-  | "purple"                                // #800080ff
-  | "fuchsia"                               // #ff00ffff
-  | "magenta"                               // #ff00ffff (= fuchsia)
-  | "green"                                 // #008000ff
-  | "lime"                                  // #00ff00ff
-  | "olive"                                 // #808000ff
-  | "yellow"                                // #ffff00ff
-  | "navy"                                  // #000080ff
-  | "blue"                                  // #0000ffff
-  | "teal"                                  // #008080ff
-  | "aqua"                                  // #00ffffff
-  | "cyan"                                  // #00ffffff (= aqua)
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>Except for <code>transparent</code>, the set of named colors specified above constitutes a proper
-subset of the set of named colors specified by <a href="#svg11">[SVG 1.1]</a>, § 4.2.</p></div></div><div class="div3">
-<h4><a id="style-value-non-negative-integer"></a>10.3.17 &lt;non-negative-integer&gt;</h4><p>A &lt;non-negative-integer&gt; expression is used to express an arbitrary, non-negative integral value.</p><a id="non-negative-integer-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;non-negative-integer&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;non-negative-integer&gt;
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-number"></a>10.3.18 &lt;number&gt;</h4><p>An &lt;number&gt; expression is used to express an arbitrary, signed integer or real valued number.</p><a id="number-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;number&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;number&gt;
-  : sign? non-negative-number
-
-sign
-  : "+" | "-"
-
-number
-
-non-negative-number
-  : <a href="#style-value-non-negative-integer">&lt;non-negative-integer&gt;</a>
-  | non-negative-real
-
-non-negative-real
-  : <a href="#style-value-digit">&lt;digit&gt;</a>* "." <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-percentage"></a>10.3.19 &lt;percentage&gt;</h4><p>An &lt;percentage&gt; expression is used to express an arbitrary, signed integral or real valued percentage.</p><a id="percentage-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;percentage&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;percentage&gt;
-  : <a href="#style-value-number">&lt;number&gt;</a> "%"
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a id="style-value-position"></a>10.3.20 &lt;position&gt;</h4><p>A &lt;position&gt; expression is used to indirectly determine the origin of an area or an image with respect to a reference area.</p><a id="position-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;position&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;position&gt;
-  : offset-position-h                       // single component value
-  | offset-position-v                       // single component value
-  | offset-position-h offset-position-v     // two component values
-  | position-keyword-h edge-offset-v        // three component values
-  | position-keyword-v edge-offset-h        // three component values
-  | edge-offset-h position-keyword-v        // three component values
-  | edge-offset-v position-keyword-h        // three component values
-  | edge-offset-h edge-offset-v             // four component values
-  | edge-offset-v edge-offset-h             // four component values
-
-offset-position-h
-  : position-keyword-h
-  | <a href="#style-value-length">&lt;length&gt;</a>
-
-offset-position-v
-  : position-keyword-v
-  | <a href="#style-value-length">&lt;length&gt;</a>
-
-edge-offset-h
-  : edge-keyword-h <a href="#style-value-length">&lt;length&gt;</a>
-
-edge-offset-v
-  : edge-keyword-v <a href="#style-value-length">&lt;length&gt;</a>
-
-position-keyword-h
-  : center
-  | edge-keyword-h
-
-position-keyword-v
-  : center
-  | edge-keyword-v
-
-edge-keyword-h
-  : left
-  | right
-
-edge-keyword-v
-  : top
-  | bottom
-</pre></div>
-</td></tr></tbody></table><p>A &lt;position&gt; expression may consist of one to four component values as follows:</p><dl><dt class="label">one component</dt><dd><p>either a horizontal offset (<code>offset-position-h</code>) or a vertical offset (<code>offset-position-v</code>)</p></dd><dt class="label">two components</dt><dd><p>a horizontal offset (<code>offset-position-h</code>) followed by a vertical offset (<code>offset-position-v</code>)</p></dd><dt class="label">three components</dt><dd><p>a horizontal edge offset (<code>edge-offset-position-h</code>) and a vertical edge offset (<code>edge-offset-position-v</code>), in any order, where one offset is a keyword and the other offset is a keyword <a href="#style-value-length">&lt;length&gt;</a> pair</p></dd><dt class="label">four components</dt><dd><p>a horizontal edge offset (<code>edge-offset-position-h</code>) and a vertical edge offset (<code>edge-offset-position-v</code>), in any order, where both offsets are keyword <a href="#style-value-length">&lt;length&gt;</a> pairs</p></dd></dl><p>Every &lt;position&gt; expression can be translated to a four component equivalent of the form
-<code>left <a href="#style-value-length">&lt;length&gt;</a> top <a href="#style-value-length">&lt;length&gt;</a></code> by means of the following
-equivalence tables:</p><a id="position-expression-one-component-equivalents"></a><table class="common"><caption>One Component Equivalents</caption><col width="25%" span="1"><col width="25%" span="1"><tbody><tr><th>Value</th><th>Equivalent</th></tr><tr><td><code>center</code></td><td><code>center center</code></td></tr><tr><td><code>left</code></td><td><code>left center</code></td></tr><tr><td><code>right</code></td><td><code>right center</code></td></tr><tr><td><code>top</code></td><td><code>center top</code></td></tr><tr><td><code>bottom</code></td><td><code>center bottom</code></td></tr><tr><td><code><a href="#style-value-length">&lt;length&gt;</a></code></td><td><code><a href="#style-value-length">&lt;length&gt;</a> center</code></td></tr></tbody></table><p></p><a id="position-expression-two-component-equivalents"></a><table class="common"><caption>Two Component Equivalents</caption><col width="25%" span="1"><col width="25%" span="1"><tbody><tr><th>Value</th><th>Equivalent</th></tr><tr><td><code>center center</code></td><td><code>left 50% top 50%</code></td></tr><tr><td><code>center top</code></td><td><code>left 50% top 0%</code></td></tr><tr><td><code>center bottom</code></td><td><code>left 50% top 100%</code></td></tr><tr><td><code>center <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 50% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>left center</code></td><td><code>left 0% top 50%</code></td></tr><tr><td><code>left top</code></td><td><code>left 0% top 0%</code></td></tr><tr><td><code>left bottom</code></td><td><code>left 0% top 100%</code></td></tr><tr><td><code>left <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 0% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>right center</code></td><td><code>left 100% top 50%</code></td></tr><tr><td><code>right top</code></td><td><code>left 100% top 0%</code></td></tr><tr><td><code>right bottom</code></td><td><code>left 100% top 100%</code></td></tr><tr><td><code>right <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 100% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code><a href="#style-value-length">&lt;length&gt;</a> center</code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 50%</code></td></tr><tr><td><code><a href="#style-value-length">&lt;length&gt;</a> top</code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 0%</code></td></tr><tr><td><code><a href="#style-value-length">&lt;length&gt;</a> bottom</code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 100%</code></td></tr><tr><td><code><a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr></tbody></table><p></p><a id="position-expression-three-component-equivalents"></a><table class="common"><caption>Three Component Equivalents</caption><col width="25%" span="1"><col width="25%" span="1"><tbody><tr><th>Value</th><th>Equivalent</th></tr><tr><td><code>bottom left <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 100%</code></td></tr><tr><td><code>bottom right <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top 100%</code></td></tr><tr><td><code>bottom <a href="#style-value-length">&lt;length&gt;</a> center</code></td><td><code>left 50% bottom <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>bottom <a href="#style-value-length">&lt;length&gt;</a> left</code></td><td><code>left 0% bottom <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>bottom <a href="#style-value-length">&lt;length&gt;</a> right</code></td><td><code>left 100% bottom <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>center bottom <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 50% bottom <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>center left <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 50%</code></td></tr><tr><td><code>center right <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top 50%</code></td></tr><tr><td><code>center top <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 50% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>left bottom <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 0% bottom <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>left top <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 0% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>left <a href="#style-value-length">&lt;length&gt;</a> bottom</code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 100%</code></td></tr><tr><td><code>left <a href="#style-value-length">&lt;length&gt;</a> center</code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 50%</code></td></tr><tr><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top</code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 0%</code></td></tr><tr><td><code>right bottom <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 100% bottom <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>right top <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left 100% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>right <a href="#style-value-length">&lt;length&gt;</a> bottom</code></td><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top 100%</code></td></tr><tr><td><code>right <a href="#style-value-length">&lt;length&gt;</a> center</code></td><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top 50%</code></td></tr><tr><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top</code></td><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top 0%</code></td></tr><tr><td><code>top left <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length&gt;</a> top 0%</code></td></tr><tr><td><code>top right <a href="#style-value-length">&lt;length&gt;</a></code></td><td><code>right <a href="#style-value-length">&lt;length&gt;</a> top 0%</code></td></tr><tr><td><code>top <a href="#style-value-length">&lt;length&gt;</a> center</code></td><td><code>left 50% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>top <a href="#style-value-length">&lt;length&gt;</a> left</code></td><td><code>left 100% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr><tr><td><code>top <a href="#style-value-length">&lt;length&gt;</a> right</code></td><td><code>left 100% top <a href="#style-value-length">&lt;length&gt;</a></code></td></tr></tbody></table><p></p><a id="position-expression-four-component-equivalents"></a><table class="common"><caption>Four Component Equivalents</caption><col width="25%" span="1"><col width="25%" span="1"><tbody><tr><th>Value</th><th>Equivalent</th></tr><tr><td><code>bottom <a href="#style-value-length">&lt;length-v&gt;</a> left <a href="#style-value-length">&lt;length-h&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length-h&gt;</a> top (100% - <a href="#style-value-length">&lt;length-v&gt;</a>)</code></td></tr><tr><td><code>bottom <a href="#style-value-length">&lt;length-v&gt;</a> right <a href="#style-value-length">&lt;length-h&gt;</a></code></td><td><code>left (100% - <a href="#style-value-length">&lt;length-h&gt;</a>) top (100% - <a href="#style-value-length">&lt;length-v&gt;</a>)</code></td></tr><tr><td><code>left <a href="#style-value-length">&lt;length-h&gt;</a> bottom <a href="#style-value-length">&lt;length-v&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length-h&gt;</a> top (100% - <a href="#style-value-length">&lt;length-v&gt;</a>)</code></td></tr><tr><td><code>right <a href="#style-value-length">&lt;length-h&gt;</a> bottom <a href="#style-value-length">&lt;length-v&gt;</a></code></td><td><code>left (100% - <a href="#style-value-length">&lt;length-h&gt;</a>) top (100% - <a href="#style-value-length">&lt;length-v&gt;</a>)</code></td></tr><tr><td><code>right <a href="#style-value-length">&lt;length-h&gt;</a> top <a href="#style-value-length">&lt;length-v&gt;</a></code></td><td><code>left (100% - <a href="#style-value-length">&lt;length-h&gt;</a>) top <a href="#style-value-length">&lt;length-v&gt;</a></code></td></tr><tr><td><code>top <a href="#style-value-length">&lt;length-v&gt;</a> left <a href="#style-value-length">&lt;length-h&gt;</a></code></td><td><code>left <a href="#style-value-length">&lt;length-h&gt;</a> top <a href="#style-value-length">&lt;length-v&gt;</a></code></td></tr><tr><td><code>top <a href="#style-value-length">&lt;length-v&gt;</a> right <a href="#style-value-length">&lt;length-h&gt;</a></code></td><td><code>left (100% - <a href="#style-value-length">&lt;length-h&gt;</a>) top <a href="#style-value-length">&lt;length-v&gt;</a></code></td></tr></tbody></table><p>If a <a href="#style-value-length">&lt;length&gt;</a> component is expressed as a percentage, then that percentage is interpreted in relation to
-some reference dimension, where the reference dimension is defined by the context of use.</p><p>A <a href="#style-value-length">&lt;length&gt;</a> component of a &lt;position&gt; expression may be positive or negative. Positive lengths are interpreted as
-insets from the referenced edge, while negative lengths are interpreted as outsets from the referenced edge. For example, an inset from the <code>left</code>
-edge is located to the right of that edge (if non-zero), while an outset from the <code>left</code> edge is located to the left of that edge (if non-zero). In
-contrast, an inset from the <code>right</code> edge is located to the left of that edge (if non-zero), while an outset from the <code>right</code> edge
-is located to the right of that edge (if non-zero). A similar arrangement holds for <code>top</code> and <code>bottom</code> edges.</p><p>When performing four component equivalent conversion, the expression <code>(100% - <a href="#style-value-length">&lt;length-h&gt;</a>)</code>
-is to be interpreted as the difference between 100% and the percentage equivalent of the <a href="#style-value-length">&lt;length-h&gt;</a>
-expression. Similarly, the expression <code>(100% - <a href="#style-value-length">&lt;length-v&gt;</a>)</code>
-is to be interpreted as the difference between 100% and the percentage equivalent of the <a href="#style-value-length">&lt;length-v&gt;</a> expression.
-In both cases, the resulting difference may be a negative percentage.</p></div><div class="div3">
-<h4><a id="style-value-shadow"></a>10.3.21 &lt;shadow&gt;</h4><p>A &lt;shadow&gt; value expresses a shadow decoration to be applied to a generated area. If
-the generated area is a glyph area, then it applies to the outline of the glyph (not the glyph area bounding box). If the
-generated area is not a glyph area, then it applies to the border rectangle of the area.</p><a id="shadow-style-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;shadow&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;shadow&gt;
-  : inset? &amp;&amp; <a href="#style-value-length">&lt;length&gt;</a>{2,4} &amp;&amp; <a href="#style-value-color">&lt;color&gt;</a>
-</pre></div>
-</td></tr></tbody></table><p>A shadow value expression consists of an optional <code>inset</code> token term,
-two to four <a href="#style-value-length">&lt;length&gt;</a> terms, and
-an optional <a href="#style-value-color">&lt;color&gt;</a> term.</p><p>The first <a href="#style-value-length">&lt;length&gt;</a> term denotes the offset in the inline progression direction of the associated area,
-where positive denotes towards the end edge and negative towards the start edge,
-the second <a href="#style-value-length">&lt;length&gt;</a> term denotes the offset in the block progression direction of the associated area,
-where positive denotes towards the after edge and negative towards the before edge.
-The third <a href="#style-value-length">&lt;length&gt;</a> term, if present, denotes the blur radius, and must be non-negative.
-The fourth <a href="#style-value-length">&lt;length&gt;</a> term, if present, denotes the spread distance, where positive denotes expansion and negative denotes contraction.</p><p>If no <a href="#style-value-color">&lt;color&gt;</a> term is
-present, then the computed value of the <code>tts:color</code> property applies.</p><p>If applied to a glyph area, then an <code>inset</code> token and a spread distance, if either or both are present, are ignored for purpose of presentation processing.</p><table border="1" class="ednote" summary="Editorial note: Shadow Inset"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Shadow Inset</b></td><td align="right" valign="top">2015-01-08</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Define semantics of <code>inset</code> term.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>When a <a href="#style-value-length">&lt;length&gt;</a> expressed in
-cells is used in a <code>tts:textShadow</code> value,
-the cell's dimension in the block progression dimension applies.
-For example, if text shadow thickness is specified as 0.1c, the cell resolution
-is 20 by 10, and the extent of the <a href="#terms-root-container-region">root container region</a> is 640 by 480, then the
-shadow thickness will be a nominal 480 / 10 * 0.1 pixels, i.e., 4.8px,
-without taking into account rasterization effects.</p></div></div></div><div class="div2">
-<h3><a id="semantics-styling"></a>10.4 Styling Semantics</h3><p>This section defines the semantics of style resolution in terms of
-a standard processing model as follows:</p><ul><li><p><a href="#semantics-style-association"><b>10.4.1 Style Association</b></a></p></li><li><p><a href="#semantics-style-inheritance"><b>10.4.2 Style Inheritance</b></a></p></li><li><p><a href="#semantics-style-resolution-value-categories"><b>10.4.3 Style Resolution Value Categories</b></a></p></li><li><p><a href="#semantics-style-resolution-processing"><b>10.4.4 Style Resolution Processing</b></a></p></li></ul><p>Any implementation of this model is permitted provided that the
-externally observable results are consistent with the results produced
-by this model.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of style resolution employed here are based upon
-<a href="#xsl11">[XSL 1.1]</a>, § 5.</p></div><div class="div3">
-<h4><a id="semantics-style-association"></a>10.4.1 Style Association</h4><p>Style association is a sub-process of <a href="#semantics-style-resolution-processing"><b>10.4.4 Style Resolution Processing</b></a> used to determine the
-specified style set of each content and
-layout element.</p><p>Style matter may be associated with content
- and layout matter in a number of ways:</p><ul><li><p><a href="#semantics-style-association-inline">inline styling</a></p></li><li><p><a href="#semantics-style-association-referential">referential styling</a></p></li><li><p><a href="#semantics-style-association-chained-referential">chained referential styling</a></p></li></ul><p>In addition to the above, style matter may be associated with layout matter using:</p><ul><li><p><a href="#semantics-style-association-nested">nested styling</a></p></li></ul><div class="div4">
-<h5><a id="semantics-style-association-inline"></a>10.4.1.1 Inline Styling</h5><p>Style properties may be expressed in an inline manner by direct
-specification of an attribute from the TT Style Namespace on the
-affected element. When expressed in this manner, the association of
-style information is referred to as <em>inline styling</em>.</p><p>Style properties associated by inline styling are afforded a higher priority than all other
-forms of style association.</p><a id="style-association-example-1"></a><table class="example"><caption>Example – Inline Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;p <span class="strong">tts:color="white"</span>&gt;White 1&nbsp;&lt;span <span class="strong">tts:color="yellow"</span>&gt;Yellow&lt;/span&gt;&nbsp;White 2&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the two text fragments <code>"White 1 "</code> and
-<code>" White 2"</code>, which are interpreted as anonymous spans, are not
-associated with a color style property; rather, they inherit their color style
-from their parent <code>p</code> element as described in <a href="#semantics-style-inheritance-content"><b>10.4.2.1 Content Style Inheritance</b></a> below.  </p></div></div><div class="div4">
-<h5><a id="semantics-style-association-referential"></a>10.4.1.2 Referential Styling</h5><p>Style properties may be expressed in an out-of-line manner and referenced by the
-affected element using the <code>style</code> attribute. When expressed in this manner,
-the association of style information is referred to as <em>referential styling</em>.</p><p>If a <code>style</code> attribute specifies multiple references, then those references are
-evaluated in the specified order, and that order applies to resolution of the value of a
-style property in the case that it is specified along multiple reference paths.</p><p>The use of referential styling is restricted to making
-reference to <code>style</code> element descendants of a <code>styling</code>
-element. It is considered an error to reference a <code>style</code>
-element that is a descendant of a <code>layout</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of referential styling encourages the reuse of style specifications while
-sacrificing locality of reference.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>A single <a href="#terms-content-element">content element</a> may be associated with style properties by a hybrid mixture of
-inline and referential styling, in which case inline styling is given priority as described above
-by <a href="#semantics-style-association-inline"><b>10.4.1.1 Inline Styling</b></a>.</p></div><a id="style-association-example-2"></a><table class="example"><caption>Example – Referential Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;style <span class="strong">xml:id="s1"</span> tts:color="white"/&gt;
-&lt;style <span class="strong">xml:id="s2"</span> tts:color="yellow"/&gt;
-...
-&lt;p <span class="strong">style="s1"</span>&gt;White 1&nbsp;&lt;span <span class="strong">style="s2"</span>&gt;Yellow&lt;/span&gt;&nbsp;White 2&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the two text fragments <code>"White 1 "</code> and
-<code>" White 2"</code>, which are interpreted as anonymous spans, are not
-associated with a color style property; rather, they inherit their color style
-from their parent <code>p</code> element as described in <a href="#semantics-style-inheritance-content"><b>10.4.2.1 Content Style Inheritance</b></a> below.</p></div></div><div class="div4">
-<h5><a id="semantics-style-association-chained-referential"></a>10.4.1.3 Chained Referential Styling</h5><p>Style properties may be expressed in an out-of-line manner and may themselves reference
-other out-of-line style properties, thus creating a chain of references starting at the
-affected element. When expressed in this manner, the association of style information
-is referred to as <em>chained referential styling</em>.</p><p>If the same style property is specified in more than one referenced
-style set, then the last referenced style set applies, where the order of application starts from
-the affected element and proceeds to referenced style sets, and, in turn, to subsequent referenced style sets.</p><p>A loop in a sequence of chained style references must be considered an error.</p><p>The use of referential styling is restricted to making
-reference to <code>style</code> element descendants of a <code>styling</code>
-element. It is considered an error to reference a <code>style</code>
-element that is a descendant of a <code>layout</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of chained referential styling encourages the grouping of style specifications
-into general and specific sets, which further aids in style specification reuse.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>A single <a href="#terms-content-element">content element</a> may be associated with style properties by a hybrid mixture of
-inline, referential styling, and chained referential styling, in which case inline styling is
-given priority as described above by <a href="#semantics-style-association-inline"><b>10.4.1.1 Inline Styling</b></a>.</p></div><a id="style-association-example-3"></a><table class="example"><caption>Example – Chained Referential Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;style <span class="strong">xml:id="s1"</span> tts:color="white" tts:fontFamily="monospaceSerif"/&gt;
-&lt;style <span class="strong">xml:id="s2"</span> <span class="strong">style="s1"</span> tts:color="yellow"/&gt;
-...
-&lt;p <span class="strong">style="s1"</span>&gt;White Monospace&lt;/p&gt;
-&lt;p <span class="strong">style="s2"</span>&gt;Yellow Monospace&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table></div><div class="div4">
-<h5><a id="semantics-style-association-nested"></a>10.4.1.4 Nested Styling</h5><p>Style properties may be expressed in a nested manner by direct specification of one or
-more <code>style</code> element children of the affected element.
-When expressed in this manner, the association of style information
-is referred to as <em>nested styling</em>.</p><p>Style properties associated by nested styling are afforded a lower priority than inline
-styling but with higher priority than referential styling.</p><a id="style-association-example-4"></a><table class="example"><caption>Example – Nested Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  <span class="strong">&lt;style tts:extent="128px 66px"/&gt;</span>
-  <span class="strong">&lt;style tts:origin="0px 0px"/&gt;</span>
-  <span class="strong">&lt;style tts:displayAlign="center"/&gt;</span>
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In this version of this specification, nested styling applies only
-to the <code>region</code> element.</p></div></div></div><div class="div3">
-<h4><a id="semantics-style-inheritance"></a>10.4.2 Style Inheritance</h4><p>Style inheritance is a sub-process of <a href="#semantics-style-resolution-processing"><b>10.4.4 Style Resolution Processing</b></a> used to determine the
-specified style set of each content and
-layout element.</p><p>Styles are further propagated to content matter
-using:
-</p><ul><li><p><a href="#semantics-style-inheritance-content">content style inheritance</a></p></li><li><p><a href="#semantics-style-inheritance-region">region style inheritance</a></p></li><li><p><a href="#semantics-style-inheritance-root">root style inheritance</a></p></li></ul><p>For the purpose of determining inherited styles, the element hierarchy of
-an intermediate synchronic document form of a <a href="#terms-document-instance">document instance</a> must be used, where
-such intermediate forms are defined by <a href="#semantics-region-layout-step-1"><b>11.3.1.3 Intermediate Synchronic Document Construction</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The intermediate synchronic document form is utilized rather than
-the original form in order to facilitate region inheritance
-processing.</p></div><div class="div4">
-<h5><a id="semantics-style-inheritance-content"></a>10.4.2.1 Content Style Inheritance</h5><p>Style properties are inherited from ancestor <a href="#terms-content-element">content elements</a>
-within an intermediate synchronic document
-if a style property is not associated with a <a href="#terms-content-element">content element</a> (or
-an anonymous span) and the style property is designated as
-inheritable.</p><p>If a style property is determined to require inheritance, then the inherited value must
-be the value of the same named style property in the computed
-style set of the
-element's nearest ancestor element that defines the property
-within the applicable intermediate synchronic document.</p><a id="style-inheritance-example-2"></a><table class="example"><caption>Example – Content Style Inheritance</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;p <span class="strong">tts:fontFamily="monospaceSansSerif"</span>&gt;
-  &lt;span tts:color="yellow"&gt;Yellow Monospace&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the <code>span</code> element that encloses the character items
-<code>Yellow Monospace</code> is not associated with a <code>tts:fontFamily</code> style
-property and this property is inheritable; therefore, the value of the
-<code>tts:fontFamily</code> style
-is inherited from the computed style
-set of the ancestor <code>p</code> element,
-and is added to the
-specified
-style
-set of the <code>span</code> element.</p></div></div><div class="div4">
-<h5><a id="semantics-style-inheritance-region"></a>10.4.2.2 Region Style Inheritance</h5><p>Style properties are inherited from a <a href="#layout-vocabulary-region">region</a> element in the following case:</p><ol class="enumar"><li><p>if an inheritable style property <em>P</em> is not associated with
-a <a href="#terms-content-element">content element</a>
-or an anonymous span <em>E</em>, and</p></li><li><p>if that style property <em>P</em> is in the computed style
-set of region <em>R</em>, and</p></li><li><p>if that element <em>E</em> is flowed into (presented within) region
-<em>R</em>.</p></li></ol><a id="style-inheritance-example-3"></a><table class="example"><caption>Example – Region Style Inheritance</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region <span class="strong">xml:id="r1"</span>&gt;
-&nbsp;&nbsp;&lt;style tts:color="yellow"/&gt;
-&nbsp;&nbsp;&lt;style tts:fontFamily="monospaceSerif"/&gt;
-&lt;/region&gt;
-...
-&lt;p <span class="strong">region="r1"</span>&gt;Yellow Monospace&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the anonymous span that encloses the character
-items <code>Yellow Monospace</code> effectively inherits the <code>tts:color</code>
-and <code>tts:fontFamily</code> styles specified on the <code>region</code>
-element into which the <code>p</code> element is flowed (presented).</p></div></div><div class="div4">
-<h5><a id="semantics-style-inheritance-root"></a>10.4.2.3 Root Style Inheritance</h5><p>Style properties are inherited from the root <a href="#document-structure-vocabulary-tt">tt</a> element in the following case:</p><ol class="enumar"><li><p>if an inheritable style property <em>P</em> is not associated with
-a <a href="#layout-vocabular-region"><code>region</code></a> element, and</p></li><li><p>if that
-style property <em>P</em> is in the computed style
-set of the root <a href="#document-structure-vocabulary-tt">tt</a> element.</p></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>Root style inheritance provides a mechanism by means of which <code>region</code> elements
-can inherit a common style rather than repeating the specification of the style on each
-<code>region</code> element.</p></div><a id="style-inheritance-example-4"></a><table class="example"><caption>Example – Root Style Inheritance</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt <span class="strong">tts:color="yellow"</span>&gt;
-...
-&lt;region xml:id="r1" <span class="strong">tts:fontFamily="monospaceSerif"</span>/&gt;
-...
-&lt;p region="r1"&gt;Yellow Monospace&lt;/p&gt;
-...
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the <code>region</code> element inherits the
-<code>tts:color</code> style specified on the <code>tt</code> element, which,
-along with the <code>tts:fontFamily</code> style specified on the <code>region</code>
-element, are inherited by <code>p</code> element when selected into the region.</p></div></div></div><div class="div3">
-<h4><a id="semantics-style-resolution-value-categories"></a>10.4.3 Style Resolution Value Categories</h4><p>During style resolution, layout, and presentation processing,
-three categories of style property values are distinguished as
-follows:</p><ul><li><p><a href="#semantics-style-resolved-value-category-specified">specified values</a></p></li><li><p><a href="#semantics-style-resolved-value-category-computed">computed values</a></p></li><li><p><a href="#semantics-style-resolved-value-category-actual">actual values</a></p></li></ul><div class="div4">
-<h5><a id="semantics-style-resolved-value-category-specified"></a>10.4.3.1 Specified Values</h5><p>Values of style properties that are associated with or inherited
-by an element or anonymous span are referred to as <em>specified values</em>. The
-set of all specified style properties of a given element is referred to
-as the <em>specified style set</em> of that element.</p></div><div class="div4">
-<h5><a id="semantics-style-resolved-value-category-computed"></a>10.4.3.2 Computed Values</h5><p>When style properties are specified using relative value expressions,
-such as a named color, a relative unit (e.g., cell), or a percentage, then
-they need to be further resolved into absolute units, such as an RGB triple,
-pixels, etc.</p><p>During the style resolution process, all specified style values are
-reinterpreted (or recalculated) in absolute terms, and then recorded as
-<em>computed values</em>. The
-set of all computed style properties of a given element is referred to
-as the <em>computed style set</em> of that element.</p><p>When a style value is inherited, either explicitly or implicitly, it
-is the computed value of the style that is inherited from an ancestor
-element. This is required since the resolution of certain relative units,
-such as percentage, require evaluating the expression in the immediate
-(local) context of reference, and not in a distant (remote) context of
-reference where the related (resolving) expression is not available.</p></div><div class="div4">
-<h5><a id="semantics-style-resolved-value-category-actual"></a>10.4.3.3 Actual Values</h5><p>During the actual presentation process, other transformations occur
-that map some value expressions to concrete, physical values. For example,
-the colors of computed style values are further subjected to closest color
-approximation and gamma correction
-during the display process. In addition, length value expressions that use
-pixels in computed style values are considered to express logical rather than
-physical (device) pixels. Consequently, these logical pixels are subject to
-being further transformed or mapped to physical (device) pixels during
-presentation.</p><p>The final values that result from the logical to device mapping
-process are referred to as <em>actual values</em>.  The set of all
-actual style properties of a given element is referred to as the
-<em>actual style set</em> of that element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>More than one set of actual values may be produced during the
-process of presentation. For example, a TTML <a href="#terms-presentation-processor">presentation processor</a>
-device may output an RGBA component video signal which is then
-further transformed by an NTSC or PAL television to produce a final
-image. In this case, both color and dimensions may further be modified
-prior to presentation.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>In general, a TTML <a href="#terms-presentation-processor">presentation processor</a> will not have access
-to actual style set values; as a consequence, no further use or reference
-to actual values is made below when formally describing the style
-resolution process.</p></div></div></div><div class="div3">
-<h4><a id="semantics-style-resolution-processing"></a>10.4.4 Style Resolution Processing</h4><p>The process of style resolution is defined herein as the procedure
-(and results thereof) for resolving (determining) the computed values
-of all style properties that apply to content and layout elements:</p><ul><li><p><a href="#semantics-style-resolution-processing-definitions"><b>10.4.4.1 Conceptual Definitions</b></a></p></li><li><p><a href="#semantics-style-resolution-processing-sss"><b>10.4.4.2 Specified Style Set Processing</b></a></p></li><li><p><a href="#semantics-style-resolution-processing-css"><b>10.4.4.3 Computed Style Set Processing</b></a></p></li><li><p><a href="#semantics-style-resolution-process-overall"><b>10.4.4.4 Style Resolution Process</b></a></p></li></ul><p>The process described here forms an integral sub-process of
-<a href="#semantics-region-layout"><b>11.3.1 Region Layout and Presentation</b></a>.</p><div class="div4">
-<h5><a id="semantics-style-resolution-processing-definitions"></a>10.4.4.1 Conceptual Definitions</h5><p>For the purpose of interpreting the style resolution processing
-model specified below, the following conceptual definitions apply:</p><dl><dt class="label">[style property]</dt><dd><p>a style property, <em>P</em>, is considered to consist of a
-tuple <code>[name, value]</code>, where the name of the
-property is a tuple <code>[namespace value,
-unqualified name]</code> and the value of the property is a
-tuple <code>[category, type, value expression]</code></p><a id="conceptual-definition-example-style-property"></a><table class="example"><caption>Example – conceptual style property</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-[
-  ["http://www.w3.org/ns/ttml#styling", "color"],
-  ["specified", <em>color</em>, "red"]
-]
-</pre></div>
-</td></tr></tbody></table><p></p></dd><dt class="label">[style (property) set]</dt><dd><p>a style (property) set consists of an unordered collection of style
-properties, where no two style properties within the set have an
-identical name, where by "identical name" is meant equality of
-namespace value of name tuple and unqualified name of name tuple;</p><p>in a specified style (property) set, the category of each style
-property is "specified"; a specified style (property) set of an
-element <em>E</em> is referred to as <em>SSS(E)</em>;</p><a id="conceptual-definition-example-specified-style-set"></a><table class="example"><caption>Example – conceptual (specified) style (property) set</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-{
-  [
-    ["http://www.w3.org/ns/ttml#styling", "backgroundColor"],
-    ["specified", <em>color</em>, 0x00FF00 ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "color"],
-    ["specified", <em>color</em>, "red" ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "fontSize"],
-    ["specified", <em>length</em>, "1c" ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "lineHeight"],
-    ["specified", <em>length</em>, "117%" ]
-  ]
-}
-</pre></div>
-</td></tr></tbody></table><p>in a computed style (property) set, the category of each style
-property is either "specified" or "computed"; a computed style (property) set of an element
-<em>E</em> is referred to as <em>CSS(E)</em>;</p><a id="conceptual-definition-example-computed-style-set"></a><table class="example"><caption>Example – conceptual (computed) style (property) set</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-{
-  [
-    ["http://www.w3.org/ns/ttml#styling", "backgroundColor"],
-    ["specified", <em>color</em>, 0x00FF00 ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "color"],
-    ["computed", <em>color</em>, 0xFF0000 ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "fontSize"],
-    ["computed", <em>length</em>, "24px" ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "lineHeight"],
-    ["computed", <em>length</em>, "28px" ]
-  ]
-}
-</pre></div>
-</td></tr></tbody></table><p></p></dd><dt class="label">[style (property) merging]</dt><dd><p>a style property <em>P<sub>new</sub></em> is merged into a
-style (property) set, <em>SS</em>, as follows: if a style property
-<em>P<sub>old</sub></em> is already present in <em>SS</em>
-where the name of <em>P<sub>new</sub></em> is identical to the
-name of <em>P<sub>old</sub></em>, then replace
-<em>P<sub>old</sub></em> in <em>SS</em> with
-<em>P<sub>new</sub></em>; otherwise, add
-<em>P<sub>new</sub></em> to <em>SS</em>;</p></dd><dt class="label">[style (property) set merging]</dt><dd><p>a style (property) set <em>SS<sub>new</sub></em> is merged into
-an existing style (property) set <em>SS<sub>old</sub></em> as
-follows: for each style property <em>P<sub>new</sub></em> in
-<em>SS<sub>new</sub></em>, merge <em>P<sub>new</sub></em> into
-<em>SS<sub>old</sub></em>;</p></dd></dl></div><div class="div4">
-<h5><a id="semantics-style-resolution-processing-sss"></a>10.4.4.2 Specified Style Set Processing</h5><p>The specified style set <em>SSS</em> of an element or
-anonymous span <em>E</em>,
-<em>SSS(E)</em>, is determined according to the following ordered
-rules:</p><ol class="enumar"><li><p><span class="strong">[initialization]</span> initialize
-the specified style set <em>SSS</em> of <em>E</em> to the
-empty set;</p></li><li><p><span class="strong">[referential and chained referential
-styling]</span> for each <code>style</code> element <em>S<sub>REF</sub></em>
-referenced by a <code>style</code> attribute specified on
-<em>E</em>, and in the order specified in the <code>style</code>
-attribute, then, if <em>S<sub>REF</sub></em> is a descendant
-of a <code>styling</code> element,
-merge the specified style set of
-<em>S<sub>REF</sub></em>, <em>SSS(S<sub>REF</sub>)</em>, into
-the specified style set of <em>E</em>,
-<em>SSS(E)</em>;</p></li><li><p><span class="strong">[nested styling]</span> for each
-nested <code>style</code> element child <em>S<sub>NEST</sub></em> of
-<em>E</em>, and in the specified order of child elements, merge
-the specified style set of <em>S<sub>NEST</sub></em>,
-<em>SSS(S<sub>NEST</sub>)</em>, into the specified style set of
-<em>E</em>, <em>SSS(E)</em>;</p></li><li><p><span class="strong">[inline styling]</span> for each
-style property <em>P</em> expressed as a specified styling
-attribute of <em>E</em>,
-merge <em>P</em> into the specified style
-set of <em>E</em>, <em>SSS(E)</em>;</p></li><li><p><span class="strong">[animation styling]</span> if the
-element type of <em>E</em> is not the animation element type
-<code>set</code>, then for each
-immediate animation (<code>set</code>) element child <em>A</em> of element <em>E</em>,
-merge the specified style set of <em>A</em>,
-<em>SSS(A)</em>, into the specified style set of <em>E</em>, <em>SSS(E)</em>;</p></li><li><p><span class="strong">[implicit inheritance and initial value fallback]</span> if the
-element type of <em>E</em> is not animation element type <code>animate</code> or <code>set</code>
-and is not styling element type <code>style</code>,
-then for each style property
-<em>P</em> in the set of style properties defined
-above in <a href="#styling-attribute-vocabulary"><b>10.2 Styling Attribute Vocabulary</b></a>, perform the
-following ordered sub-steps:</p><ol class="enumla"><li><p>if <em>P</em> is present in the specified
-style set of <em>E</em>, <em>SSS(E)</em>, then continue to the
-next style property;</p></li><li><p>if <em>P</em> is defined to be inheritable and <em>E</em> is
-not the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element, then perform the following:</p><ul><li><p>set <em>P′</em> to the result of
-looking up the value of <em>P</em> in the computed style set of
-the nearest ancestor element of <em>E</em>, <em>NEAREST-ANCESTOR(E)</em>, such that
-<em>CSS(NEAREST-ANCESTOR(E))</em> contains a definition of <em>P</em>;</p></li></ul></li><li><p>otherwise (<em>P</em> is not inheritable or <em>E</em> is
-the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element), perform the following:</p><ul><li><p>set <em>P′</em> to the initial value of
-property <em>P</em>, where the initial value of a property is
-determined as follows:</p><ol class="enumlr"><li><p>if an <a href="#styling-vocabulary-initial"><code>initial</code></a>
-element defines the initial value for <em>P</em>, then use that value;</p></li><li><p>otherwise, use the initial value specified by the property definition of <em>P</em> found above
-in <a href="#styling-attribute-vocabulary"><b>10.2 Styling Attribute Vocabulary</b></a>;</p></li></ol></li></ul></li><li><p>if the value of <em>P′</em> is not undefined, then merge
-<em>P′</em> into the specified style set of <em>E</em>,
-<em>SSS(E)</em>.</p></li></ol></li></ol></div><div class="div4">
-<h5><a id="semantics-style-resolution-processing-css"></a>10.4.4.3 Computed Style Set Processing</h5><p>The computed style set <em>CSS</em> of an element or
-anonymous span <em>E</em>,
-<em>CSS(E)</em>, is determined according to the following ordered
-rules:</p><ol class="enumar"><li><p><span class="strong">[resolve specified styles]</span>
-determine (obtain) the specified style set <em>SSS</em> of
-<em>E</em>, namely, <em>SSS(E)</em>, in accordance with
-<a href="#semantics-style-resolution-processing-sss"><b>10.4.4.2 Specified Style Set Processing</b></a>;</p></li><li><p><span class="strong">[initialization]</span>
-initialize <em>CSS(E)</em> to a (deep) copy of
-<em>SSS(E)</em>;</p></li><li><p><span class="strong">[filter]</span> if
-<em>E</em> is an <code>animate</code>, <code>set</code>, or <code>style</code> element, then return
-<em>CSS(E)</em> as the resulting computed style set without
-further resolution; otherwise, continue with the next rule;</p></li><li><p><span class="strong">[relative value resolution]</span> for each
-style property <em>P</em> in <em>CSS(E)</em>, where the value
-type of <em>P</em> is relative, perform the following ordered
-sub-steps:</p><ol class="enumla"><li><p>replace the relative value of <em>P</em> with an
-equivalent, non-relative (computed) value;</p></li><li><p>set the category of <em>P</em> to "computed";</p></li></ol></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>As a result of the filtering rule above, the computed style set of
-an <code>animate</code>, <code>set</code>, or <code>style</code> element includes only specified values, in which case
-relative value expressions remain relative; consequently, the
-resolution of relative value expressions (that may be assigned by
-means of referential style association) always takes place in the
-context of a layout or <a href="#terms-content-element">content element</a> which has a presentation
-context, and not in the non-presentation, declaration context
-of an <code>animate</code>, <code>set</code>, or referable <code>style</code> element.</p></div></div><div class="div4">
-<h5><a id="semantics-style-resolution-process-overall"></a>10.4.4.4 Style Resolution Process</h5><p>The top-level style resolution process is defined as follows: using
-a preorder traversal of each element and <em>anonymous span</em>,
-<em>E</em>, of an intermediate synchronic document,
-<em>DOC<sub>inter</sub></em>, perform the following ordered
-sub-steps:</p><ol class="enumar"><li><p><span class="strong">[filter]</span> if <em>E</em>
-is not one of the following, then continue to the next element in the preorder traversal, i.e.,
-do not perform the subsequent step below on <em>E</em>:</p><ul><li><p><a href="#document-structure-vocabulary-tt"><code>tt</code></a></p></li><li><p><a href="#styling-vocabulary-style"><code>style</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li><li><p><a href="#content-vocabulary-br"><code>br</code></a></p></li><li><p><a href="#animation-vocabulary-animate"><code>animate</code></a></p></li><li><p><a href="#animation-vocabulary-set"><code>set</code></a></p></li><li><p><em>anonymous span</em></p></li></ul></li><li><p> <span class="strong">[resolve computed styles]</span>
-determine (obtain) the computed style set <em>CSS</em> of
-<em>E</em>, namely, <em>CSS(E)</em>, in accordance with
-<a href="#semantics-style-resolution-processing-css"><b>10.4.4.3 Computed Style Set Processing</b></a>.</p></li></ol></div></div><div class="div3">
-<h4><a id="semantics-style-automatic-measure-calculation"></a>10.4.5 Automatic Measure Calculation</h4><table border="1" class="ednote" summary="Editorial note: Automatic Measures"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Automatic Measures</b></td><td align="right" valign="top">2014-11-30</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Define semantics for resolving the <code>auto</code> value as used with a  <a href="#style-value-measure">&lt;measure&gt;</a> expression,
-the definition of which should be consistent with <a href="#css3-box">[CSS Box Model]</a>, § 15.</td></tr></table></div></div></div><div class="div1">
-<h2><a id="layout"></a>11 Layout</h2><p>This section specifies the <em>layout</em> matter of the core
-vocabulary catalog, where
-layout is to be understood as a separable layer of information that applies to
-content and that denotes authorial intentions about the presentation of
-that content.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The two layers of layout and style matter are considered to be independently
-separable. Layout matter specifies one or more spaces or areas into
-which content is intended to be presented, while style matter specifies the manner in
-which presentation occurs within the layout.</p><p>In certain cases, a content author may choose to embed (inline) style matter directly
-into layout or content matter. In such cases, an alternative 
-exists – use of referential styling –
-in which the style
-matter is not embedded (inlined).</p></div><div class="div2">
-<h3><a id="layout-element-vocabulary"></a>11.1 Layout Element Vocabulary</h3><p>The following elements specify the structure and principal layout aspects of a
-<a href="#terms-document-instance">document instance</a>:</p><ul><li><p><a href="#layout-vocabulary-layout"><b>11.1.1 layout</b></a></p></li><li><p><a href="#layout-vocabulary-region"><b>11.1.2 region</b></a></p></li></ul><div class="div3">
-<h4><a id="layout-vocabulary-layout"></a>11.1.1 layout</h4><p>The <code>layout</code> element is a container element used to group
-out-of-line layout matter, including metadata that applies to layout matter.</p><p>The <code>layout</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group, followed by
-zero or more <code>region</code> elements.</p><a id="elt-syntax-layout"></a><table class="syntax"><caption>XML Representation – Element Information Item: layout</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;layout
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#layout-vocabulary-region">region</a>*
-&lt;/layout&gt;
-</pre></div>
-</td></tr></tbody></table><p>To the extent that time semantics apply to the content of the
-<code>layout</code> element, the implied time interval of this element is
-defined to be coterminous with the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p></div><div class="div3">
-<h4><a id="layout-vocabulary-region"></a>11.1.2 region</h4><p>The <code>region</code> element is used to define a rectangular space or area into which content is
-to be flowed for the purpose of presentation.</p><p>A <code>region</code> element may appear as either (1) a child of a
-<a href="#layout-vocabulary-layout">layout</a> element or (2) a child of block level
-<a href="#terms-content-element">content element</a>, specifically, of elements
-in the <a href="#element-vocab-group-block">Block.class</a> element group.
-In the former case, the region is referred to as an <a href="#terms-out-of-line-region">out-of-line region</a>, while in the latter
-case, it is referred to as an <a href="#terms-inline-region">inline region</a>.</p><p>In addition, and in accordance with
-<a href="#semantics-style-inheritance-region"><b>10.4.2.2 Region Style Inheritance</b></a>, 
-the <code>region</code> element may be used to specify inheritable style properties to be
-inherited by content that is flowed into it.</p><p>The <code>region</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more
-elements in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a> element group,
-followed by
-zero or more <code>style</code> elements.</p><p>Any metadata specified by children in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a>
-element group applies semantically to the <code>region</code> element and its descendants as a whole.
-Any animation elements specified by children in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a>
-element group apply semantically to the <code>region</code> element.
-Any <code>style</code> child element must be considered a local style
-definition that applies only to the containing <code>region</code>
-element, i.e., does not apply for resolving referential styling (but does apply for region
-style inheritance).</p><a id="elt-syntax-region"></a><table class="syntax"><caption>XML Representation – Element Information Item: region</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region
-  <a href="#animation-attribute-animate">animate</a> = IDREFS
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#metadata-attribute-role">ttm:role</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*, <a href="#styling-vocabulary-style">style</a>*
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><p>An <a href="#terms-out-of-line-region">out-of-line</a> <code>region</code> element
-must specify an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute.</p><p>An <a href="#terms-out-of-line-region">out-of-line</a> <code>region</code> element may specify one or more of the timing attributes:
-<code>begin</code>, <code>end</code>, <code>dur</code>. An <a href="#terms-inline-region">inline</a> <code>region</code> element must not
-specifiy a timing attribute, and, if specified, must be ignored for the purpose
-of presentation processing.</p><p>If <code>begin</code> and (or) <code>end</code> attributes are specified on an out-of-line
-<code>region</code> element, then they specify the beginning and (or) ending points
-of a time interval during which the region is eligible for activation and with
-respect to which animation child elements of the region are timed.
-If specified, these begin and end points are relative to the time
-interval of the nearest ancestor element associated with a time
-interval, irregardless of whether that interval is explicit or implied.
-The nearest ancestor element of an out-of-line <code>region</code> element that is associated
-with a time interval is the <code>layout</code> element.
-If a <code>dur</code> attribute is specified on an out-of-line <code>region</code> element, then it
-specifies the simple duration of the region.</p><p>The active time interval of an <a href="#terms-inline-region">inline</a> <code>region</code> element is the
-active time interval of its parent <a href="#terms-content-element">content element</a>.</p><p>For the purpose of determining the semantics of presentation processing, a
-region that is temporally inactive must not produce any visible marks when
-presented on a visual medium.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>An <a href="#terms-out-of-line-region">out-of-line</a> <code>region</code> element may be associated with a time interval for two
-purposes: (1) in order to temporally bound the presentation of the region and
-its content, and (2) to provide a temporal context in which animations of region
-styles may be effected.</p><p>For example, an author may wish to specify an <a href="#terms-out-of-line-region">out-of-line</a> <code>region</code> element that is otherwise empty, but
-may have a visible background color to be presented starting at some time and
-continuing over the region's duration.  The simple duration of the region serves
-additionally to scope the presentation effects of content that is targeted to the
-region. An author may also wish to move a region within the <a href="#terms-root-container-region">root container region</a>
-or change a region's background color by means of animation effects. In
-both of these cases, it is necessary to posit an active time interval for a
-region.</p><p>In contrast to <a href="#terms-out-of-line-region">out-of-line regions</a>, <a href="#terms-inline-region">inline regions</a> are specifically bound to
-the temporal context of their parent <a href="#terms-content-element">content elements</a>,
-and, as such, do not require (or admit) the specification of independent timing.</p></div><p>If no <code>timeContainer</code> attribute is specified on
-a <code>region</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p><p>If both <a href="#style-attribute-origin"><code>tts:origin</code></a> and <a href="#style-attribute-position"><code>tts:position</code></a> attributes are present
-on a <code>region</code> element, then the <a href="#style-attribute-origin"><code>tts:origin</code></a> must be ignored for the purpose of presentation processing.
-If neither <a href="#style-attribute-origin"><code>tts:origin</code></a> nor <a href="#style-attribute-position"><code>tts:position</code></a> attribute is present and
-if the computed value of the the <a href="#parameter-attribute-version"><code>ttp:version</code></a> attribute on the root <code>tt</code> element is two (2) or greater, then
-the semantics of the initial value of the <a href="#style-attribute-position"><code>tts:position</code></a> attribute apply for the purpose of presentation processing; otherwise, the semantics of the initial value of the <a href="#style-attribute-origin"><code>tts:origin</code></a> attribute apply.</p><p>If a <a href="#metadata-attribute-role"><code>ttm:role</code></a> attribute is
-specified on a <code>region</code> element, then it must adhere to the
-value syntax defined by <a href="#metadata-attribute-role-syntax"><b>Syntax Representation – ttm:role</b></a>, and where the roles identified
-by this attribute express the semantic roles of the region
-independently from the semantic roles of any content targeted to
-(associated with) the region.</p></div></div><div class="div2">
-<h3><a id="layout-attribute-vocabulary"></a>11.2 Layout Attribute Vocabulary</h3><p>This section defines the <a href="#layout-attribute-region"><b>11.2.1 region</b></a> attribute used with <a href="#terms-content-element">content elements</a>.</p><div class="div3">
-<h4><a id="layout-attribute-region"></a>11.2.1 region</h4><p>The <code>region</code> attribute is used to reference a <code>region</code>
-element which defines a space or area into which a <a href="#terms-content-element">content element</a> is intended to be flowed.</p><p>If specified, the value of a <code>region</code> attribute must
-adhere to the <code>IDREF</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§ 3.3.9, and, furthermore, this IDREF must reference a <code>region</code> element
-which has a <code>layout</code> element as an ancestor.</p><p>The <code>region</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li><li><p><a href="#content-vocabulary-br"><code>br</code></a></p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#semantics-region-layout"><b>11.3.1 Region Layout and Presentation</b></a> below for further information on content
-flow in a region.</p></div></div></div><div class="div2">
-<h3><a id="semantics-layout"></a>11.3 Layout Semantics</h3><div class="issue"><p class="prefix"><a id="issue-365"></a><b>Issue (issue-365):</b></p><p class="prefix"><b>HTML Mapping</b></p><p><b>Source</b>: <a href="https://www.w3.org/AudioVideo/TT/tracker/issues/365">https://www.w3.org/AudioVideo/TT/tracker/issues/365</a></p><p>Define HTML5 mapping while separating ISD generation from follow-on mappings.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><div class="div3">
-<h4><a id="semantics-region-layout"></a>11.3.1 Region Layout and Presentation</h4><p>This section defines the semantics of region layout and
-presentation in terms of a standard processing model as
-follows:</p><ul><li><p><a href="#semantics-default-region"><b>11.3.1.1 Default Region</b></a></p></li><li><p><a href="#semantics-inline-regions"><b>11.3.1.2 Inline Regions</b></a></p></li><li><p><a href="#semantics-region-layout-step-1"><b>11.3.1.3 Intermediate Synchronic Document Construction</b></a></p></li><li><p><a href="#semantics-region-layout-step-2"><b>11.3.1.4 Synchronic Flow Processing</b></a></p></li><li><p><a href="#semantics-region-layout-example"><b>11.3.1.5 Elaborated Example (Non-Normative)</b></a></p></li></ul><p>Any
-implementation is permitted provided that the externally observable
-results are consistent with the results produced by this model.
-</p><div class="div4">
-<h5><a id="semantics-default-region"></a>11.3.1.1 Default Region</h5><p>If a <a href="#terms-document-instance">document instance</a> does not specify an
-<a href="#terms-out-of-line-region">out-of-line region</a>,
-then a <em>default region</em> is implied with the following characteristics:</p><ul><li><p>the identity of the default region is considered to be an anonymous <a href="#terms-out-of-line-region">out-of-line region</a>;</p></li><li><p>the extent of the default region is the same as the extent of the <a href="#terms-root-container-region">root container region</a>;</p></li><li><p>the temporal interval of the default region is the same as the interval defined by the <a href="#terms-root-temporal-extent">root temporal extent</a>;</p></li></ul><p>Furthermore, if no
-<a href="#terms-out-of-line-region">out-of-line region</a> is specified, then the
-<a href="#layout-attribute-region"><code>region</code></a> attribute must
-not be specified on any <a href="#terms-content-element">content element</a> in the <a href="#terms-document-instance">document instance</a>.</p><p>If a default region is implied for a given <a href="#terms-document-instance">document instance</a>, then
-the <a href="#document-structure-vocabulary-body"><code>body</code></a> element
-is implicitly targeted to (associated with) the default region.</p><p>When implying a default region, the <a href="#terms-document-instance">document instance</a> is to be
-treated as if a <a href="#layout-vocabulary-region"><code>region</code></a> element and its
-parent <a href="#layout-vocabulary-layout"><code>layout</code></a>
-element were specified in a <a href="#document-structure-vocabulary-head"><code>head</code></a>
-element, and a matching <a href="#layout-attribute-region"><code>region</code></a> attribute were
-specified on the <a href="#document-structure-vocabulary-body"><code>body</code></a> element
-as shown in the following example:</p><a id="semantics-default-region-example"></a><table class="example"><caption>Example – Implied Default Region</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head&gt;
-    <span class="strong">&lt;layout&gt;
-      &lt;region xml:id="anonymous"/&gt;
-    &lt;/layout&gt;</span>
-  &lt;/head&gt;
-  &lt;body <span class="strong">region="anonymous"</span>/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a default <code>region</code> element and <code>region</code>
-attribute are implied. In addition, a <code>layout</code> container element is implied for
-the implied <code>region</code> element.</p></div></div><div class="div4">
-<h5><a id="semantics-inline-regions"></a>11.3.1.2 Inline Regions</h5><p>An <a href="#terms-inline-region">inline region</a> is a syntactic mechanism for specifying a
-<a href="#terms-region">region</a> in a way that minimizes the syntactic distance between a region
-specification and the content that references that region. Semantically, each
-<a href="#terms-inline-region">inline region</a> is equivalent to specifying a unique
-<a href="#terms-out-of-line-region">out-of-line region</a> referenced implicitly only by the
-<a href="#terms-content-element">content element</a> in whose context the
-<a href="#terms-inline-region">inline region</a> is specified (or implied).</p><p>An <a href="#terms-inline-region">inline region</a> is declared in one of two ways:
-(1) by specifying a <a href="#style-attribute-extent"><code>tts:extent</code></a> or
-<a href="#style-attribute-origin"><code>tts:origin</code></a> style attribute on
-a <a href="#terms-content-element">content element</a>
-in the <a href="#element-vocab-group-block">Block.class</a> element group, or
-(2) by specifying an explicit  <a href="#layout-vocabulary-region"><code>region</code></a> element
-child of a <a href="#terms-content-element">content element</a>
-in the <a href="#element-vocab-group-block">Block.class</a> element group. The
-former is referred to as an <em>implied inline region specification</em>,
-the latter as an <em>explicit inline region specification</em>; furthermore, the former is considered
-to be a syntactic shorthand for the latter, and is processed by converting it into the latter as
-described below.</p><p>Inline regions are processed in accordance with the procedure
-<span class="strong"><a href="#procedure-process-inline-regions">[process inline regions]</a></span>, which
-entails first generating implied inline regions, and then generating out-of-line regions that correspond with implied
-or explicit inline regions. This latter procedure additionally binds content elements associated with inline regions
-to the corresponding generated out-of-line regions.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <a href="#terms-content-element">content element</a> can only be associated with a single
-<a href="#terms-region">region</a>. Consequently, if a <a href="#terms-content-element">content element</a>
-specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute, then any <em>implied inline region specification</em>
-or <em>explicit inline region specification</em> is ignored. If the <a href="#terms-content-element">content element</a> does not specify a
-<a href="#layout-attribute-region"><code>region</code></a> attribute, but it includes
-both an <em>implied inline region specification</em> and an <em>explicit inline region specification</em>,
-then the former is ignored in favor of the latter.</p></div><dl><dt class="label"><a id="procedure-process-inline-regions"></a>[process inline regions]</dt><dd><ol class="enumar"><li><p>perform procedure <span class="strong"><a href="#procedure-generate-inline-regions">[generate inline regions]</a></span>;</p></li><li><p>perform procedure <span class="strong"><a href="#procedure-generate-out-of-line-regions">[generate out-of-line regions]</a></span>;</p></li></ol></dd><dt class="label"><a id="procedure-generate-inline-regions"></a>[generate inline regions]</dt><dd><p>For each <a href="#terms-content-element">content element</a> <em>B</em>
-in the <a href="#element-vocab-group-block">Block.class</a> element group,
-perform the following ordered steps:</p><ol class="enumar"><li><p>if the <code>[attributes]</code> information item property of <em>B</em> contains
-neither <a href="#style-attribute-extent"><code>tts:extent</code></a> nor
-<a href="#style-attribute-origin"><code>tts:origin</code></a> style attribute, then exit this procedure;</p></li><li><p>if the <code>[attributes]</code> information item property of <em>B</em> contains a
-<a href="#layout-attribute-region"><code>region</code></a> attribute, then exit this procedure</p></li><li><p>if the <code>[children]</code> information item property of <em>B</em> contains a
-<a href="#layout-vocabulary-region"><code>region</code></a> element, then exit this procedure;</p></li><li><p>create an empty <a href="#layout-vocabulary-region"><code>region</code></a> element <em>R</em>,
-initialized as follows:</p><ul><li><p>if the <code>[attributes]</code> information item property of <em>B</em> contains a
-<a href="#style-attribute-extent"><code>tts:extent</code></a> attribute,
-then copy that attribute to the <code>[attributes]</code> information item property of <em>R</em>;
-otherwise, add a <a href="#style-attribute-extent"><code>tts:extent</code></a> attribute with value <code>auto</code>
-to the <code>[attributes]</code> information item property of <em>R</em>;</p></li><li><p>if the <code>[attributes]</code> information item property of <em>B</em> contains a
-<a href="#style-attribute-origin"><code>tts:origin</code></a> attribute,
-then copy that attribute to the <code>[attributes]</code> information item property of <em>R</em>;
-otherwise, add a <a href="#style-attribute-origin"><code>tts:origin</code></a> attribute with value <code>auto</code>
-to the <code>[attributes]</code> information item property of <em>R</em>;</p></li></ul></li><li><p>insert <em>R</em> into the <code>[children]</code> information item property of <em>B</em>
-such that <em>R</em> immediately precedes the first <a href="#terms-content-element">content element</a>
-child of <em>B</em>, or, if none is present, then <em>R</em> is the last child element of <em>B</em>;</p></li><li><p>remove the <a href="#style-attribute-extent"><code>tts:extent</code></a> and
-<a href="#style-attribute-origin"><code>tts:origin</code></a> style attributes, if present, from the
-<code>[attributes]</code> information item property of <em>B</em>;</p></li></ol></dd><dt class="label"><a id="procedure-generate-out-of-line-regions"></a>[generate out-of-line regions]</dt><dd><p>For each <a href="#terms-content-element">content element</a> <em>B</em>
-in the <a href="#element-vocab-group-block">Block.class</a> element group,
-perform the following ordered steps:</p><ol class="enumar"><li><p>if the <code>[attributes]</code> information item property of <em>B</em> contains a
-<a href="#layout-attribute-region"><code>region</code></a> attribute, then exit this procedure</p></li><li><p>if the <code>[children]</code> information item property of <em>B</em> does not contain
-a <a href="#layout-vocabulary-region"><code>region</code></a> element <em>R</em>, then exit this procedure;</p></li><li><p>create an empty <a href="#layout-vocabulary-region"><code>region</code></a> element <em>R'&nbsp;</em>,
-initialized as follows:</p><ul><li><p>set the <code>[children]</code> information item property of <em>R'&nbsp;</em> to a deep copy of
-the <code>[children]</code> information item property of <em>R</em>;</p></li><li><p>set the <code>[attributes]</code> information item property of <em>R'&nbsp;</em> to a deep copy of
-the <code>[attributes]</code> information item property of <em>R</em>;</p></li><li><p>if the <code>[attributes]</code> information item property of <em>R'&nbsp;</em> does not include
-an <code>xml:id</code> attribute, then add an implied <code>xml:id</code> attribute with a generated value
-<em>ID</em> that is unique within the scope of the TTML <a href="#terms-document-instance">document instance</a>;
-otherwise, let <em>ID</em> be the value of the <code>xml:id</code> attribute of <em>R'&nbsp;</em>;</p></li><li><p>if present, remove the following attributes from the <code>[attributes]</code> information item property of <em>R'&nbsp;</em>:
-<code>begin</code>,
-<code>dur</code>, and
-<code>end</code>;</p></li><li><p>add a <code>begin</code> attribute to the <code>[attributes]</code> information item property of <em>R'&nbsp;</em> with
-a value equivalent to the computed begin time of <em>B</em> within the root temporal extent;</p></li><li><p>add a <code>dur</code> attribute to the <code>[attributes]</code> information item property of <em>R'&nbsp;</em> with
-a value equivalent to the computed simple duration of <em>B</em>;</p></li></ul></li><li><p>if the TTML <a href="#terms-document-instance">document instance</a> does not have a
-<a href="#document-structure-vocabulary-head"><code>head</code></a> element, then insert an empty
-<a href="#document-structure-vocabulary-head"><code>head</code></a> element as the first child of
-the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element;</p></li><li><p>if the <a href="#document-structure-vocabulary-head"><code>head</code></a> element does not have
-a <a href="#layout-vocabulary-layout"><code>layout</code></a> child element, then insert an empty
-<a href="#layout-vocabulary-layout"><code>layout</code></a> element immediately after a
-<a href="#styling-vocabulary-styling"><code>styling</code></a> element, if present, and immediately before an
-<a href="#animation-vocabulary-styling"><code>animation</code></a> element, if present, or as the last child of
-the <a href="#document-structure-vocabulary-head"><code>head</code></a> element if neither are present;</p></li><li><p>append <em>R'&nbsp;</em> to the <code>[children]</code> information item property of the
-<a href="#layout-vocabulary-layout"><code>layout</code></a> element child of the 
-<a href="#document-structure-vocabulary-head"><code>head</code></a> element;</p></li><li><p>add a <a href="#layout-attribute-region"><code>region</code></a> attribute with value <em>ID</em> to the <code>[attributes]</code> information
-item property of <em>B</em>;</p></li><li><p>remove <em>R</em> from the <code>[children]</code> information item property of <em>B</em>;</p></li></ol><div class="issue"><p class="prefix"><a id="issue-324"></a><b>Issue (issue-324):</b></p><p class="prefix"><b>Duration Restrictions</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/324">http://www.w3.org/AudioVideo/TT/tracker/issues/324</a></p><p>Handle case where use of <code>dur</code> is not permitted, e.g., when using discontinuous SMPTE time base.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div></dd></dl><p>The use of an <em>implied inline region specification</em> and the resulting generated inline region is shown by the following two example documents.</p><a id="semantics-inline-region-input-example-1-implied"></a><table class="example"><caption>Example – Implied Inline Region Specification</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head/&gt;
-  &lt;body&gt;
-    &lt;div <span class="strong">tts:extent="540px 100px" tts:origin="50px 339px"</span>&gt;
-      &lt;p&gt;Some Content&lt;/p&gt;
-    &lt;div/&gt;
-  &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="semantics-generated-out-of-line-region-example-1-implied"></a><table class="example"><caption>Example – Generated Inline Region</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head/&gt;
-  &lt;body&gt;
-    &lt;div&gt;
-      <span class="strong">&lt;region tts:extent="540px 100px" tts:origin="50px 339px"/&gt;</span>
-      &lt;p&gt;Some Content&lt;/p&gt;
-    &lt;div/&gt;
-  &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>The use of an <em>explicit inline region specification</em> or a generated inline region that derives from
-an <em>implicit inline region specification</em>
-and the resulting generated out-of-line region is shown by the following two example documents.</p><a id="semantics-inline-region-input-example-2-explicit"></a><table class="example"><caption>Example – Explicit or Generated Inline Region Specification</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head/&gt;
-  &lt;body&gt;
-    &lt;div begin="5s" dur="10s"&gt;
-      <span class="strong">&lt;region tts:extent="540px 100px" tts:origin="50px 339px"/&gt;</span>
-      &lt;p&gt;Some Content&lt;/p&gt;
-    &lt;div/&gt;
-  &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p></p><a id="semantics-generated-out-of-line-region-example-2-explicit"></a><table class="example"><caption>Example – Generated Out-of-line Region</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head&gt;
-    <span class="strong">&lt;layout&gt;
-      &lt;region xml:id="region3451" begin="5s" dur="10s" tts:extent="540px 100px" tts:origin="50px 339px"/&gt;
-    &lt;/layout&gt;</span>
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;div begin="5s" dur="10s" <span class="strong">region="region3451"</span>&gt;
-      &lt;p&gt;Some Content&lt;/p&gt;
-    &lt;div/&gt;
-  &lt;body/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table></div><div class="div4">
-<h5><a id="semantics-region-layout-step-1"></a>11.3.1.3 Intermediate Synchronic Document Construction</h5><table border="1" class="ednote" summary="Editorial note: Use Formalized ISD"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Use Formalized ISD</b></td><td align="right" valign="top">2014-09-22</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Revise in order to take into account new formalization of ISD structure and semantics (Appendix C).</td></tr></table><p>For the purposes of performing presentation processing, the active time
-duration of a <a href="#terms-document-instance">document instance</a> is divided into a sequence of time coordinates where at
-each time coordinate, some element becomes temporally active or inactive,
-then, at each such time coordinate, a <a href="#terms-document-instance">document instance</a> is mapped from its original, source
-form, <em>DOC<sub>source</sub></em> , 
-to an intermediate
-synchronic document form,
-<em>DOC<sub>inter</sub></em> , according to the
-<span class="strong"><a href="#procedure-construct-intermediate-document">[construct intermediate document]</a></span> procedure:</p><dl><dt class="label"><a id="procedure-construct-intermediate-document"></a>[construct intermediate document]</dt><dd><ol class="enumar"><li><p>perform procedure <span class="strong"><a href="#procedure-process-inline-regions">[process inline regions]</a></span>;</p></li><li><p>for each temporally active region <em>R</em>, replicate the
-sub-tree
- of <em>DOC<sub>source</sub></em>
-headed by the <code>body</code> element;</p></li><li><p>evaluating this sub-tree in a postorder traversal, prune elements if they
-are not a <a href="#terms-content-element">content element</a>, if they are temporally inactive, if they are empty,
-or if they aren't associated with region <em>R</em> according to the
-<span class="strong"><a href="procedure-associate-region">[associate region]</a></span> procedure;</p></li><li><p>if the pruned sub-tree is non-empty, then reparent it to the <em>R</em>
-element;</p></li><li><p>finally, after completing the above steps, prune the original <code>body</code>
-element from the intermediate document, then prune all <code>region</code>,
-<code>begin</code>, <code>end</code>, and <code>dur</code> attributes, which are no
-longer semantically relevant;</p></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>In this section, the term <em>prune</em>, when used in reference to
-an element, means that the element is to be removed from its parent's children,
-which, in turn, implies that the descendants of the pruned element will no longer
-be descendants of the element's parent. When <em>prune</em> is used in
-reference to an attribute, it means that attribute is to be removed from its
-associated (owning) element node.</p></div></dd><dt class="label"><a id="procedure-associate-region"></a>[associate region]</dt><dd><p></p><div class="issue"><p class="prefix"><a id="issue-341"></a><b>Issue (issue-341):</b></p><p class="prefix"><b>Multiple Descendant Region Ambiguitty</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/341">http://www.w3.org/AudioVideo/TT/tracker/issues/341</a></p><p>Refine step (3) to resolve ambiguity when multiple regions are referenced by descendants.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p></p><table border="1" class="ednote" summary="Editorial note: Inline Region Association"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Inline Region Association</b></td><td align="right" valign="top">2013-08-28</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Define inline region association.</td></tr></table><p>A <a href="#terms-content-element">content element</a> is associated with a region according
-to the following ordered rules, where the first rule satisfied
-is used and remaining rules are skipped:</p><ol class="enumar"><li><p>if the element specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute,
-then the element is associated with the region referenced by that
-attribute;</p></li><li><p>if some ancestor of that element specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute,
-then the element is associated with the region referenced by the most
-immediate ancestor that specifies this attribute;</p></li><li><p> if the element contains a descendant element that
-specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute,
-then the element is associated with the region referenced by that
-attribute;</p></li><li><p>if a default region was implied (due to the absence of any
-<a href="#layout-vocabulary-region"><code>region</code></a> element),
-then the element is associated with the default region;</p></li><li><p>the element is not associated with any region.</p></li></ol></dd></dl><p>The result of performing the processing described above will be a sequence of
-<em>N</em> intermediate  synchronic
-<a href="#terms-document-instance">document instances</a>,
-<em>DOC<sub><span>inter<sub>0</sub></span></sub></em> …
-<em>DOC<sub><span>inter<sub>N−1</sub></span></sub></em>.</p><div class="note" id="semantics-smooth-scrolling-recommendation"><p class="prefix"><b>Note:</b></p><p>Where an implementation is able to detect significant similarity between two
-adjacent synchronic <a href="#terms-document-instance">document instances</a>,
-<em>DOC<sub><span>inter<sub>N</sub></span></sub></em>
-<em>DOC<sub><span>inter<sub>N−1</sub></span></sub></em>,
-then it is preferred that the implementation make the transition between
-presenting the two instances as smooth as possible, e.g., as described
-by <a href="#cea608e">[CEA-608-E]</a>, § C.3, and <a href="#ccreq">[CC-DECODER-REQ]</a>.</p></div></div><div class="div4">
-<h5><a id="semantics-region-layout-step-2"></a>11.3.1.4 Synchronic Flow Processing</h5><p>Subsequent to performing a temporal (synchronic) slice and subsequent
-remapping of regionally selected content hierarchy, the resulting intermediate
-synchronic document is subjected to a flow transformation step that produces 
-a rooted flow object tree represented as an XSL FO document instance as defined by <a href="#xsl11">[XSL 1.1]</a>,
-and semantically extended by TTML specific style properties that have no XSL
-FO counterpart.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this section, the use of XSL FO is intended to be conceptual only, employed
-solely for the purpose of defining the normative presentation semantics of
-TTML. An actual implementation of this algorithm is not required to create or process
-XSL-FO representations. In particular, it is possible to implement these semantics
-using alternative presentation models, such as Cascading Style Sheets (CSS).</p></div><p>Each intermediate synchronic document produced by <a href="#semantics-region-layout-step-1"><b>11.3.1.3 Intermediate Synchronic Document Construction</b></a> is mapped 
-to an XSL FO document instance, <em>F</em>, as follows:</p><ol class="enumar"><li><p>perform the following ordered sub-steps to create anonymous spans:</p><ol class="enumla"><li><p>for each significant text node in a <a href="#terms-content-element">content element</a>,
-synthesize an anonymous span to enclose the text node, substituting
-the new anonymous span for the original text node child in its sibling
-and parent hierarchy;</p></li><li><p>for each contiguous sequence of anonymous spans, replace the
-sequence with a single anonymous span which contains a sequence of
-text nodes representing the individual text node children of the
-original sequence of anonymous spans;</p></li><li><p>for each span element whose child is a single anonymous span,
-replace the anonymous span with its sequence of child text
-nodes;</p></li></ol></li><li><p>resolve styles according to <a href="#semantics-style-resolution-process-overall"><b>10.4.4.4 Style Resolution Process</b></a>;</p></li><li><p>map the <code>tt</code> element to an <code>fo:root</code> element, populated
-initially with an <code>fo:layout-master-set</code> element that contains a valid
-<code>fo:simple-page-master</code> that, in turn, contains an
-<code>fo:region-body</code> child, where the extent of the <a href="#terms-root-container-region">root container region</a> expressed on the
-<code>tt</code> element is mapped to <code>page-width</code> and
-<code>page-height</code> attributes on the <code>fo:simple-page-master</code>
-element;</p></li><li><p>map the <code>layout</code> element to an <code>fo:page-sequence</code> element and a
-child <code>fo:flow</code> element that reference the page master and page region
-defined by the simple page master produced above;</p></li><li><p>map each non-empty <code>region</code> element to an <code>fo:block-container</code>
-element with an <code>absolute-position</code> attribute with value
-<code>absolute</code>, with <code>top</code>, <code>left</code>, <code>bottom</code>, and <code>right</code>
-attributes that express a rectangle equivalent to the region's origin and
-extent, and with a <code>line-stacking-strategy</code> attribute with value <code>line-height</code>;</p></li><li><p>for each <code>body</code>, <code>div</code>, and <code>p</code> element that is not
-associated with a <code>tts:display</code> style property with the value
-<code>none</code>, map the element to a distinct <code>fo:block</code> element,
-populating the style properties of <code>fo:block</code> by using the computed
-style set associated with each original TTML <a href="#terms-content-element">content element</a>;</p></li><li><p>for the resulting <code>fo:block</code> formatting object
-produced in the previous step that corresponds to the <code>body</code>
-element, perform the following ordered sub-steps:</p><ol class="enumla"><li><p>if the <code>display-align</code> style property of this <code>fo:block</code>
-has the value <code>center</code> or <code>after</code>,
-then synthesize and insert as the first child of this <code>fo:block</code>
-an empty <code>fo:block</code> with the following attributes:
-<code>space-after.optimum</code>, <code>space-after.maximum</code>, and
-<code>space-after.conditionality</code>, where the value of the former
-two attributes is the height or width of the containing
-<code>fo:block-container</code> element, whichever of these is designated
-as the block progression dimension, and where the value of the last is
-<code>retain</code>;</p></li><li><p>if the <code>display-align</code> style property of this <code>fo:block</code>
-has the value <code>center</code> or <code>before</code>,
-then synthesize and insert as the last child of this <code>fo:block</code>
-an empty <code>fo:block</code> with the following attributes:
-<code>space-after.optimum</code>, <code>space-after.maximum</code>, and
-<code>space-after.conditionality</code>, where the value of the former
-two attributes is the height or width of the containing
-<code>fo:block-container</code> element, whichever of these is designated
-as the block progression dimension, and where the value of the last is
-<code>retain</code>;</p></li></ol></li><li><p>for each <code>span</code> element that is not
-associated with a <code>tts:display</code> style property with the value
-<code>none</code> and for each anonymous
-span that is a child of a <code>p</code> or <code>span</code> element,
-map the element or
-sequence of character items to a distinct <code>fo:inline</code> element,
-populating the style properties of <code>fo:inline</code> by using the computed
-style set associated with each original TTML <a href="#terms-content-element">content element</a>
-or anonymous span;</p></li><li><p>for each <code>br</code> element that is not
-associated with a <code>tts:display</code> style property with the value
-<code>none</code>, map the element to
-a distinct <code>fo:character</code> element having the following
-properties:</p><ul><li><p><code>character="&amp;#x000A;"</code></p></li><li><p><code>suppress-at-line-break="retain"</code></p></li></ul></li><li><p>for each TTML style property attribute in some computed
-style set that
-has no counterpart in <a href="#xsl11">[XSL 1.1]</a>, map that attribute directly through
-to the relevant formatting object produced by the input TTML <a href="#terms-content-element">content element</a> to
-which the style property applies;</p></li><li><p>optionally, synthesize a unique <code>id</code> attribute on each resulting
-formatting object element that relates that element to the input element that
-resulted in that formatting object element;</p></li></ol><p>For each resulting document instance F, if processing requires presentation on a 
-visual medium, then apply formatting and rendering semantics consistent with that 
-prescribed by <a href="#xsl11">[XSL 1.1]</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In an XSL FO area tree produced by formatting <em>F</em> using 
-an <a href="#xsl11">[XSL 1.1]</a> formatting processor, 
-the <code>page-viewport-area</code>,
-which is generated by <code>fo:page-sequence</code> element by
-reference to the sole generated <code>fo:simple-page-master</code>
-element, would correspond to the <a href="#terms-root-container-region">root container region</a> defined
-above in <a href="#definitions"><b>2 Definitions</b></a>.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>When mapping a <code>region</code> element to <code>fo:block-container</code>, it may
-be necessary to use a negative offset as a value for one or more of the
-<code>top</code>, <code>left</code>, <code>bottom</code>, and <code>right</code>
-XSL-FO properties in case the region extends outside of its containing block.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>Due to the possible presence of TTML style properties or style property values
-in a given <a href="#terms-document-instance">document instance</a> for which there is no <a href="#xsl11">[XSL 1.1]</a> counterpart,
-Implementors should recognize that it is the layout model of <a href="#xsl11">[XSL 1.1]</a> that is being referenced
-by this specification, not the requirement to use a compliant <a href="#xsl11">[XSL 1.1]</a> formatting processor,
-since such would not necessarily be sufficient to satisfy the full presentation semantics
-defined by this specification, and would contain a large number of features not needed to
-implement the presentation semantics of TTML.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The purpose of inserting additional, collapsible space in the block progression
-dimension of the <code>fo:block</code> that corresponds with the <code>body</code> element
-is to ensure that the before and after edges of this <code>fo:block</code> are coincident
-with the before and after edges of the <code>fo:block-container</code> that corresponds
-to the containing <code>region</code>, while simultaneously taking into account the needs
-to satisfy alignment in the block progression dimension. For example, this assures that
-the background color associated with the <code>body</code> element, if not <code>transparent</code>,
- will fill the containing region wholly.</p></div></div><div class="div4">
-<h5><a id="semantics-region-layout-example"></a>11.3.1.5 Elaborated Example (Non-Normative)</h5><p>An example of the processing steps described above is elaborated below, starting with <a href="#region-mapping-example-1-s"><b>Example – Sample Source Document</b></a>.</p><a id="region-mapping-example-1-s"></a><table class="example"><caption>Example – Sample Source Document</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-  &lt;body xml:id="b1"&gt;
-    &lt;div xml:id="d1" begin="0s" dur="2s"&gt;
-      &lt;p xml:id="p1" region="r1"&gt;Text 1&lt;/p&gt;
-      &lt;p xml:id="p2" region="r2"&gt;Text 2&lt;/p&gt;
-    &lt;/div&gt;
-    &lt;div xml:id="d2" begin="1s" dur="2s"&gt;
-      &lt;p xml:id="p3" region="r2"&gt;Text 3&lt;/p&gt;
-      &lt;p xml:id="p4" region="r1"&gt;Text 4&lt;/p&gt;
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>In the above document, the content hierarchy consists of two divisions, each
-containing two paragraphs. This content is targeted (associated with) one of two
-non-overlapping regions that are styled identically except for their position
-and their foreground colors, the latter of which is inherited by and applies to
-the (and, in this case, anonymous) spans reparented into the regions.</p><p>The following, first intermediate document shows the synchronic state for time
-interval [0,1), during which time only division <code>d1</code> is temporally active,
-and where paragraphs <code>p1</code> and <code>p2</code> (and their ancestors)
-are associated with regions <code>r1</code> and <code>r2</code>, respectively.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The intermediate documents shown below are not valid <a href="#terms-document-instance">document instances</a>,
-but rather, are representations of possible internal processing states used for
-didactic purposes.</p></div><a id="region-mapping-example-1-i0"></a><table class="example"><caption>Example – Intermediate Document – [0s,1s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-1"&gt;
-          &lt;div xml:id="d1-1"&gt;
-            &lt;p xml:id="p1"&gt;Text 1&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-2"&gt;
-          &lt;div xml:id="d1-2"&gt;
-            &lt;p xml:id="p2"&gt;Text 2&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>An XSL FO document instance that would yield rendering consistent with TTML, and 
-which may be produced by performing flow processing upon the first intermediate 
-document is illustrated below.</p><a id="region-mapping-example-1-f0"></a><table class="example"><caption>Example – XSL FO Document – [0s,1s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"&gt;
-  &lt;fo:layout-master-set&gt;
-    &lt;fo:simple-page-master master-name="m1"
-      page-width="640px" page-height="480px"&gt;
-      &lt;fo:region-body/&gt;
-    &lt;/fo:simple-page-master&gt;
-  &lt;/fo:layout-master-set&gt;
-  &lt;fo:page-sequence master-reference="m1"&gt;
-    &lt;fo:flow flow-name="xsl-region-body"&gt;
-      &lt;!-- region (r1) --&gt;
-      &lt;fo:block-container id="r1" absolute-position="absolute"
-        left="10px" top="100px" width="620px" height="96px"
-        background-color="black" display-align="center"&gt;
-        &lt;!-- body (b1) --&gt;
-        &lt;fo:block id="b1-1"&gt;
-          &lt;!-- body's space (before) filler --&gt;
-          &lt;fo:block
-            space-after.optimum="96px"
-            space-after.maximum="96px"
-            space-after.conditionality="retain"/&gt;
-          &lt;!-- div (d1) --&gt;
-          &lt;fo:block id="d1-1"&gt;
-            &lt;!-- p (p1) --&gt;
-            &lt;fo:block id="p1" text-align="center"&gt;
-              &lt;fo:inline font-size="40px" font-weight="bold"
-              color="red"&gt;Text 1&lt;/fo:inline&gt;
-            &lt;/fo:block&gt;
-          &lt;/fo:block&gt;
-          &lt;!-- body's space (after) filler --&gt;
-          &lt;fo:block
-            space-after.optimum="96px"
-            space-after.maximum="96px"
-            space-after.conditionality="retain"/&gt;
-        &lt;/fo:block&gt;
-      &lt;/fo:block-container&gt;
-      &lt;!-- region (r2) --&gt;
-      &lt;fo:block-container id="r2" absolute-position="absolute"
-        left="10px" top="300px" width="620px" height="96px"
-        background-color="black" display-align="center"&gt;
-        &lt;!-- body (b1) --&gt;
-        &lt;fo:block id="b1-2"&gt;
-          &lt;!-- body's space (before) filler --&gt;
-          &lt;fo:block
-            space-after.optimum="96px"
-            space-after.maximum="96px"
-            space-after.conditionality="retain"/&gt;
-          &lt;!-- div (d1) --&gt;
-          &lt;fo:block id="d1-2"&gt;
-            &lt;!-- p (p2) --&gt;
-            &lt;fo:block id="p2" text-align="center"&gt;
-              &lt;fo:inline font-size="40px" font-weight="bold"
-              color="yellow"&gt;Text 2&lt;/fo:inline&gt;
-            &lt;/fo:block&gt;
-          &lt;/fo:block&gt;
-          &lt;!-- body's space (after) filler --&gt;
-          &lt;fo:block
-            space-after.optimum="96px"
-            space-after.maximum="96px"
-            space-after.conditionality="retain"/&gt;
-        &lt;/fo:block&gt;
-      &lt;/fo:block-container&gt;
-    &lt;/fo:flow&gt;
-  &lt;/fo:page-sequence&gt;
-&lt;/fo:root&gt;
-</pre></div>
-</td></tr></tbody></table><p>The following, second intermediate document shows the synchronic state for
-time interval [1,2), during which time both divisions <code>d1</code> and
-<code>d2</code> are temporally active, and where paragraphs <code>p1</code> and
-<code>p4</code> (and their ancestors) are associated with region <code>r1</code>
-and paragraphs <code>p2</code> and <code>p3</code> (and their ancestors) are
-associated with region <code>r2</code>.</p><a id="region-mapping-example-1-i1"></a><table class="example"><caption>Example – Intermediate Document – [1s,2s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-1"&gt;
-          &lt;div xml:id="d1-1"&gt;
-            &lt;p xml:id="p1"&gt;Text 1&lt;/p&gt;
-          &lt;/div&gt;
-          &lt;div xml:id="d2-1"&gt;
-            &lt;p xml:id="p4"&gt;Text 4&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-2"&gt;
-          &lt;div xml:id="d1-2"&gt;
-            &lt;p xml:id="p2"&gt;Text 2&lt;/p&gt;
-          &lt;/div&gt;
-          &lt;div xml:id="d2-2"&gt;
-            &lt;p xml:id="p3"&gt;Text 3&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>The following, third intermediate document shows the synchronic state for time
-interval [2,3), during which time only division <code>d2</code> is temporally active,
-and where paragraphs <code>p4</code> and <code>p3</code> (and their ancestors)
-are associated with regions <code>r1</code> and <code>r2</code>, respectively.</p><a id="region-mapping-example-1-i2"></a><table class="example"><caption>Example – Intermediate Document – [2s,3s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-1"&gt;
-          &lt;div xml:id="d2-1"&gt;
-            &lt;p xml:id="p4"&gt;Text 4&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-2"&gt;
-          &lt;div xml:id="d2-2"&gt;
-            &lt;p xml:id="p3"&gt;Text 3&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table></div></div><div class="div3">
-<h4><a id="semantics-line-layout"></a>11.3.2 Line Layout</h4><p>If a profile that applies to a <a href="#terms-document-instance">document instance</a>
-requires use of the <a href="#feature-lineBreak-uax14">#lineBreak-uax14</a> feature
-(i.e., the value attribute for the feature is specified as <code>use</code>), then
-the recommendations defined by <a href="http://www.unicode.org/reports/tr14/#Algorithm">Line
-Breaking Algorithm</a> <a href="#uax14">[UAX14]</a> apply when performing
-line layout on the content of the <a href="#terms-document-instance">document instance</a>.</p></div></div></div><div class="div1">
-<h2><a id="timing"></a>12 Timing</h2><p>This section specifies the <em>timing</em> matter of the core
-vocabulary catalog, where
-timing is to be understood as a separable layer of information that applies to
-content and that denotes authorial intentions about the temporal presentation of
-that content.</p><div class="div2">
-<h3><a id="timing-element-vocabulary"></a>12.1 Timing Element Vocabulary</h3><p>No timing related element vocabulary is defined for use in the core
-vocabulary catalog.</p></div><div class="div2">
-<h3><a id="timing-attribute-vocabulary"></a>12.2 Timing Attribute Vocabulary</h3><p>This section defines the following basic timing attributes for use with timed elements:</p><ul><li><p><a href="#timing-attribute-begin"><b>12.2.1 begin</b></a></p></li><li><p><a href="#timing-attribute-dur"><b>12.2.2 dur</b></a></p></li><li><p><a href="#timing-attribute-end"><b>12.2.3 end</b></a></p></li></ul><p>In addition, this section defines the <a href="#timing-attribute-timeContainer"><b>12.2.4 timeContainer</b></a> attribute for use with timed elements
-that serve simultaneously as timing containers.</p><div class="div3">
-<h4><a id="timing-attribute-begin"></a>12.2.1 begin</h4><p>The <code>begin</code> attribute is used to specify the begin
-point of a temporal interval associated with a timed element. If
-specified, the value of a <code>begin</code> attribute must adhere to
-a &lt;timeExpression&gt; specification as defined by <a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a>.</p><p>The begin point of a temporal interval is included in the
-interval; i.e., the interval is left-wise closed.</p><p>The semantics of the <code>begin</code> attribute are those defined
-by <a href="#smil3">[SMIL 3.0]</a>, § 5.4.3,
-while taking into account any overriding semantics defined by this specification.</p></div><div class="div3">
-<h4><a id="timing-attribute-dur"></a>12.2.2 dur</h4><p>The <code>dur</code> attribute is used to specify the duration of a
-temporal interval associated with a timed element. If specified,
-the value of a <code>dur</code> attribute must adhere to a
-&lt;timeExpression&gt; specification as defined by <a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When the <code>clock-time</code> form of a &lt;timeExpression&gt; specification
-is used with a <code>dur</code> attribute, it is intended to be interpreted as
-a difference between two implied clock time expressions.</p></div><p>When a <a href="#terms-document-instance">document instance</a> specifies the use of the
-<code>smpte</code> time base and <code>discontinuous</code> marker
-mode, a (well-formed) <code>dur</code> attribute must not be specified on any
-element.</p><p>The semantics of the <code>dur</code> attribute are those defined
-by <a href="#smil3">[SMIL 3.0]</a>, § 5.4.3,
-while taking into account any overriding semantics defined by this specification.
-In a deliberate divergence from <a href="#smil3">[SMIL 3.0]</a>, § 5.4.3, the value of
-the <code>dur</code> attribute is permitted to be zero (0).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In the context of the subset of <a href="#smil3">[SMIL 3.0]</a> semantics supported by
-this specification, the active duration of an element that specifies both
-<code>end</code> and <code>dur</code> attributes is equal to the lesser of the value of
-the <code>dur</code> attribute and the difference between the value of the
-<code>end</code> attribute and the element's begin time.</p></div></div><div class="div3">
-<h4><a id="timing-attribute-end"></a>12.2.3 end</h4><p>The <code>end</code> attribute is used to specify the ending point
-of a temporal interval associated with a timed element. If
-specified, the value of an <code>end</code> attribute must adhere to a
-&lt;timeExpression&gt; specification as defined by <a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a>.</p><p>The ending point of a temporal interval is not included in the
-interval; i.e., the interval is right-wise open.</p><p>The presentation effects of a non-empty active
-temporal interval include the frame immediately prior to the frame
-(or tick) equal to or immediately following the time specified by the ending
-point, but do not extend into this latter frame (or tick).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, if an active interval is [10s,10.33333s), and the
-frame rate is 30 frames per second, then the presentation effects of the interval
-are limited to frames 300 through 309 only (assuming that 0s corresponds
-with frame 0). The same holds if the active interval is specified
-as [300f,310f).</p></div><p>The semantics of the <code>end</code> attribute are those defined
-by <a href="#smil3">[SMIL 3.0]</a>, § 5.4.3,
-while taking into account any overriding semantics defined by this specification.</p></div><div class="div3">
-<h4><a id="timing-attribute-timeContainer"></a>12.2.4 timeContainer</h4><p>The <code>timeContainer</code> attribute is used to specify a local temporal
-context by means of which timed child elements are temporally situated.</p><p>If specified, the value of a <code>timeContainer</code> attribute must be one
-of the following:</p><ul><li><p><code>par</code></p></li><li><p><code>seq</code></p></li></ul><p>If the time container semantics of an element instance is <code>par</code>,
-then the temporal intervals of child elements are considered to apply in
-parallel, i.e., simultaneously in time. Furthermore, the specification of
-the time interval of each child element is considered to be relative to the temporal
-interval of the container element instance. For the purpose of determining the
-<a href="#smil3">[SMIL 3.0]</a> <code>endsync</code> semantics of a <code>par</code>
-time container, a default value of <code>all</code> applies.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of a default value of <code>all</code> for the <code>endsync</code>
-behavior is distinct from <a href="#smil3">[SMIL 3.0]</a> which uses a default value
-of <code>last</code>.</p></div><p>If the time container semantics of an element instance is <code>seq</code>,
-then the temporal intervals of child elements are considered to apply in
-sequence, i.e., sequentially in time. Furthermore, the specification of
-the time interval of each child element is considered to be relative to the temporal
-interval of its sibling elements, unless it is the first child element, in which case
-it is considered to be relative to the temporal interval of the container
-element instance.</p><p>Each time container is considered to constitute an independent time base, i.e.,
-time coordinate system.</p><p>If a <code>timeContainer</code> attribute is not specified on an element that
-has time container semantics, then <code>par</code> time container semantics must apply.</p><p>Time container semantics applies only to the following element types:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li></ul><p>The semantics of parallel and sequential time
-containment are those defined by <a href="#smil3">[SMIL 3.0]</a>, § 5.4.4,
-while taking into account any overriding semantics defined by this specification.</p></div></div><div class="div2">
-<h3><a id="timing-time-value-expressions"></a>12.3 Time Value Expressions</h3><p>Timing attribute values include the use of the following expressions:</p><ul><li><p><a href="#timing-value-timeExpression"><b>12.3.1 &lt;timeExpression&gt;</b></a></p></li></ul><div class="div3">
-<h4><a id="timing-value-timeExpression"></a>12.3.1 &lt;timeExpression&gt;</h4><p>A &lt;timeExpression&gt; is used to specify a coordinate within
-some time base, where the applicable time base is determined by the
-<code>ttp:timeBase</code> parameter, and where the semantics defined
-by <a href="#time-expression-semantics"><b>H Time Expression Semantics</b></a> apply.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See
-<a href="#parameter-attribute-frameRate"><b>7.2.4 ttp:frameRate</b></a>,
-<a href="#parameter-attribute-subFrameRate"><b>7.2.11 ttp:subFrameRate</b></a>,
-<a href="#parameter-attribute-tickRate"><b>7.2.12 ttp:tickRate</b></a>, and
-<a href="#parameter-attribute-timeBase"><b>7.2.13 ttp:timeBase</b></a> for further information on
-explicit specification of frame rate, sub-frame rate, tick rate, and time base.</p></div><div class="issue"><p class="prefix"><a id="issue-293"></a><b>Issue (issue-293):</b></p><p class="prefix"><b>Dates in Time Expressions</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/293">http://www.w3.org/AudioVideo/TT/tracker/issues/293</a></p><p>Consider adding dates to time expressions to handle issues around midnight crossings and related use cases.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p></p><a id="timeExpression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;timeExpression&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : clock-time
-  | offset-time
-
-clock-time
-  : hours ":" minutes ":" seconds ( fraction | ":" frames ( "." sub-frames )? )?
-
-offset-time
-  : time-count fraction? metric?
-
-hours
-  : <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>
-  | <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-minutes | seconds
-  : <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>
-
-frames
-  : <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>
-  | <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-sub-frames
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-fraction
-  : "." <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-time-count
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-metric
-  : "h"                 // hours
-  | "m"                 // minutes
-  | "s"                 // seconds
-  | "ms"                // milliseconds
-  | "f"                 // frames
-  | "t"                 // ticks
-</pre></div>
-</td></tr></tbody></table><p>If a &lt;timeExpression&gt; is expressed in terms of a
-<em>clock-time</em>, then leading zeroes are used when expressing hours,
-minutes, seconds, and frames less than 10. Minutes are constrained to
-[0…59], while seconds (including any fractional part) are constrained to the closed
-interval [0,60], where the value 60 applies only to leap seconds.</p><p>If a &lt;timeExpression&gt; is expressed in terms of a
-<em>clock-time</em> and a <em>frames</em> term is specified,
-then the value of this term must be constrained to the interval
-[0…<em>F-1</em>], where <em>F</em> is the frame rate
-determined by the <code>ttp:frameRate</code> parameter as defined
-by <a href="#parameter-attribute-frameRate"><b>7.2.4 ttp:frameRate</b></a>.
-It is considered an error if a <em>frames</em> term or
-<code>f</code> (frames) metric is specified when the <code>clock</code> time base applies.</p><p>If a &lt;timeExpression&gt; is expressed in terms of a
-<em>clock-time</em> and a <em>sub-frames</em> term is
-specified, then the value of this term must be constrained to the
-interval [0…<em>S-1</em>], where <em>S</em> is the
-sub-frame rate determined by the <code>ttp:subFrameRate</code> parameter as defined by <a href="#parameter-attribute-subFrameRate"><b>7.2.11 ttp:subFrameRate</b></a>.
-It is considered an error if a <em>sub-frames</em> term is specified
-when the <code>clock</code> time base applies.</p><p>If a &lt;timeExpression&gt; is expressed in terms of an
-<em>offset-time</em> and no <em>metric</em> is specified, then it is to be treated as
-if a metric of <code>s</code> (seconds) were specified.</p></div></div><div class="div2">
-<h3><a id="semantics-timing"></a>12.4 Timing Semantics</h3><p>The semantics of time containment, durations, and intervals defined by
-<a href="#smil3">[SMIL 3.0]</a> apply to the interpretation of like-named timed elements and timing
-vocabulary defined by this specification, given the following
-constraints:</p><div class="issue"><p class="prefix"><a id="issue-338"></a><b>Issue (issue-338):</b></p><p class="prefix"><b>Implicit Duration of Singleton Span</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/338">http://www.w3.org/AudioVideo/TT/tracker/issues/338</a></p><p>Refine definition implicit duration of singleton span in a sequential container.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><ul><li><p>The implicit duration of an anonymous span is defined as follows: if
-the anonymous span's parent time container is a parallel time container, then
-the implicit duration is equivalent to the <code>indefinite</code>
-duration value as defined by <a href="#smil3">[SMIL 3.0]</a>; if the anonymous span's
-parent time container is a sequential time container, then the implicit duration
-is equivalent to zero.</p></li><li><p>The implicit duration of a <code>body</code>, <code>div</code>, <code>p</code>,
-or <code>span</code> element is determined in accordance to (1) whether
-the element is a parallel or sequential time container, (2) the default
-<code>endsync</code> semantics defined above by <a href="#timing-attribute-timeContainer"><b>12.2.4 timeContainer</b></a>,
-and (3) the semantics of <a href="#smil3">[SMIL 3.0]</a> as applied to these time
-containers.</p></li><li><p>The implicit duration of the <code>region</code> element is defined to
-be equivalent to the <code>indefinite</code>
-duration value as defined by <a href="#smil3">[SMIL 3.0]</a>.</p></li><li><p>If the governing time base is <code>clock</code>, then time
-expressions are considered to be equivalent to wall-clock
-based timing in <a href="#smil3">[SMIL 3.0]</a>, where the specific semantics of
-<a href="#time-expression-semantics-clock"><b>H.1 Clock Time Base</b></a> apply.</p></li><li><p>If the governing time base is <code>media</code>, then time
-expressions are considered to be equivalent to offset based timing
-in <a href="#smil3">[SMIL 3.0]</a>, where the specific semantics of
-<a href="#time-expression-semantics-media"><b>H.2 Media Time Base</b></a> apply.</p></li><li><p>If the governing time base is <code>smpte</code>, then time
-expressions are considered to be equivalent to either offset
-based timing or event based timing in <a href="#smil3">[SMIL 3.0]</a>, where the specific semantics of
-<a href="#time-expression-semantics-smpte"><b>H.3 SMPTE Time Base</b></a> apply.</p></li></ul></div></div><div class="div1">
-<h2><a id="animation"></a>13 Animation</h2><p>This section specifies the <em>animation</em> matter of the
-core vocabulary catalog, where
-animation is to be understood as a separable layer of information that combines
-timing and styling in order to denote authorial intention about (temporally) dynamic
-styling of content.</p><table border="1" class="ednote" summary="Editorial note: Out-of-Line Animation Time Containment"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Out-of-Line Animation Time Containment</b></td><td align="right" valign="top">2014-07-31</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Support ability for author to declare whether a referenced out-of-line animation's timing is relative
-to its <code>animation</code> container element's timing or relative to the referring element's timing.
-For example, add an <code>@animateTimeContainer</code> attribute optionally used with the newly defined
-<code>@animate</code> attribute, where value can be <code>normal</code> (the default value) or <code>self</code>, and where <code>normal</code>
-means timing is with respect to the out-of-line animation element's ancestor <code>animation</code> container and <code>self</code> means timing is
-with respect to the referring element.</td></tr></table><div class="div2">
-<h3><a id="animation-element-vocabulary"></a>13.1 Animation Element Vocabulary</h3><p>The following elements specify the structure and principal animation aspects of a
-<a href="#terms-document-instance">document instance</a>:</p><ul><li><p><a href="#animation-vocabulary-animate"><b>13.1.1 animate</b></a></p></li><li><p><a href="#animation-vocabulary-animation"><b>13.1.2 animation</b></a></p></li><li><p><a href="#animation-vocabulary-set"><b>13.1.3 set</b></a></p></li></ul><div class="div3">
-<h4><a id="animation-vocabulary-animate"></a>13.1.1 animate</h4><p>The <code>animate</code> element expresses a series of changes (animations) to be applied (targeted) to one or more style property attributes of associated elements.</p><div class="issue"><p class="prefix"><a id="issue-355"></a><b>Issue (issue-355):</b></p><p class="prefix"><b>Marquee</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/355">http://www.w3.org/AudioVideo/TT/tracker/issues/355</a></p><p>Consider whether semantics of ARIB-TT's marquee extension can be handled by <code>animate</code>, and, if not, then consider extending.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>An <code>animate</code> element may appear as either (1) a child of a
-<a href="#terms-content-element">content element</a> or a <a href="#layout-vocabulary-region"><code>region</code></a> element,
-referred to as <a href="#terms-inline-animation">inline animation</a>, or
-(2) a child of an <a href="#animation-vocabulary-animation">animation</a> element, referred to as
-<a href="#terms-out-of-line-animation">out-of-line animation</a>.
-In the former case, the parent of the <code>animate</code> element is the associated element; in the latter
-case, any element that references the <code>animate</code> element using an <code>animate</code> attribute is
-an associated element.</p><p>The <code>animate</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group.</p><a id="elt-syntax-animate"></a><table class="syntax"><caption>XML Representation – Element Information Item: animate</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;animate
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  calcMode = <a href="#animation-value-calcMode">&lt;calcMode&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  fill = <a href="#animation-value-fill">&lt;fill&gt;</a>
-  keySplines = <a href="#animation-value-keySplines">&lt;keySplines&gt;</a>
-  keyTimes = <a href="#animation-value-keyTimes">&lt;keyTimes&gt;</a>
-  repeatCount = <a href="#animation-value-repeatCount">&lt;repeatCount&gt;</a>
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*
-&lt;/animate&gt;
-</pre></div>
-</td></tr></tbody></table><p>An <a href="#terms-out-of-line-animation">out-of-line</a> <code>animate</code> element
-must specify an <a href="#content-attribute-xml-id"><code>xml:id</code></a> attribute.</p><p>Style property attributes targeted by an <code>animate</code> element are specified directly using
-attributes in the TT Style namespace or in a namespace that is not a TT namespace, where the list (sequence) of animation (key) values
-adhere to the <a href="#animation-value-animationValueList">&lt;animationValueList&gt;</a> syntax, and where each
-constituent <a href="#animation-value-animationValue">&lt;animationValue&gt;</a> adheres to the syntax of the specified
-attribute.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In contrast with <a href="#svg11">[SVG 1.1]</a>, §19.2.12, a single <code>animate</code> element, as defined here, may be used to
-perform continuous animations on a set of targeted style property attributes instead of being limited to targeting a single style property attribute.
-In <a href="#svg11">[SVG 1.1]</a>, this would require the use of multiple <code>animate</code> elements rather than a single <code>animate</code> element.</p><p>Furthermore, by using direct specification of animated style property and key values, it is not necessary to employ the <code>from</code>,
-<code>to</code>, <code>by</code>, or <code>values</code> animation value attributes defined by <a href="#svg11">[SVG 1.1]</a>, §19.2.9.</p></div><p>Except for the constraints or variations enumerated below, the semantics of the <code>animate</code> element and its attributes
-enumerated above are defined to be those specified by <a href="#svg11">[SVG 1.1]</a>, §19.2.12:</p><ol class="enumar"><li><p>The attributes targeted by an <code>animate</code> element and the key values to be applied to these attributes are
-specified by direct use of attributes in the TT Style namespace or a namespace that is not a TT namespace (as opposed to using
-SVG's <code>attributeName</code> and <code>from</code>,  <code>to</code>, <code>by</code>, or <code>values</code> attributes).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, specifying <code>tts:color="red;green;blue"</code> is
-considered equivalent to specifying <code>attributeName="tts:color"</code> and <code>values="red;green;blue"</code> in <a href="#svg11">[SVG 1.1]</a>.</p></div></li><li><p>If no <code>calcMode</code> attribute is specified, then a <em>calcMode</em> value of <code>linear</code> applies.</p></li><li><p>If no <code>fill</code> attribute is specified, then a <em>fill</em> value of <code>remove</code> applies.</p></li></ol><p>An example of using the <code>animate</code> element to animate content
-styling is illustrated below:</p><a id="animation-vocabulary-animate-example-1"></a><table class="example"><caption>Example Fragment – Content Style Animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;p dur="5s"&gt;
-<span class="strong">&lt;animate tts:color="yellow;red;green;blue;yellow"/&gt;</span>
-Text with Continuously Varying Colors!
-&lt;/p&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the foreground color of the content "Text
-with Continuously Varying Colors!" is continuously animated from yellow, to red, to green, to
-red, then back to yellow over a 5 second period.</p></div><p>An example of using the <code>animate</code> element to animate region
-styling is illustrated below:</p><a id="animation-vocabulary-animate-example-2"></a><table class="example"><caption>Example Fragment – Region Style Animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"
-    xmlns:ttp="http://www.w3.org/ns/ttml#parameter"
-    xmlns:tts="http://www.w3.org/ns/ttml#styling"
-    ttp:extent="640px 480px"&gt;
-    &lt;head&gt;
-      &lt;layout&gt;
-	&lt;region xml:id="r1" timeContainer="seq" tts:opacity="0"&gt;
-	  <span class="strong">&lt;animate dur="1s" tts:opacity="0;1"/&gt;</span>
-	  &lt;set dur="5s" tts:opacity="1"/&gt;
-	  <span class="strong">&lt;animate dur="1s" tts:opacity="1;0"/&gt;</span>
-	  &lt;style tts:extent="480px 60px"/&gt;
-	  &lt;style tts:origin="80px 400px"/&gt;
-	&lt;/region&gt;
-      &lt;/layout&gt;
-    &lt;/head&gt;
-    &lt;body region="r1"&gt;...&lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a region, <code>r1</code>, is initially set to 0% opacity,
-fully transparent, then is faded in to 100% opacity, fully opaque, over a one second
-interval. Opacity remains at 100% for five more seconds, and then is faded out to 0%
-over a one second interval, where it remains.</p></div><p></p><table border="1" class="ednote" summary="Editorial note: Animate Example Images"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Animate Example Images</b></td><td align="right" valign="top">2013-08-25</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert animated SVG images of animate examples.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the <code>animate</code> element
-are based upon that defined by <a href="#svg11">[SVG 1.1]</a>,
-§19.2.12, which, in turn, is based upon <a href="#smil3">[SMIL 3.0]</a>, §12.</p></div></div><div class="div3">
-<h4><a id="animation-vocabulary-animation"></a>13.1.2 animation</h4><p>The <code>animation</code> element is a container element used to group
-<a href="#terms-out-of-line-animation">out-of-line animation</a> matter, including metadata that applies to animation matter.</p><p>The <code>animation</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group, followed by
-zero or more elements in the <a href="#element-vocab-group-animation"><code>Animation.class</code></a> element group.</p><a id="elt-syntax-animation"></a><table class="syntax"><caption>XML Representation – Element Information Item: animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;animation
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#element-vocab-group-animation">Animation.class</a>*
-&lt;/animation&gt;
-</pre></div>
-</td></tr></tbody></table><p>To the extent that time semantics apply to the content of the
-<code>animation</code> element, the implied time interval of this element is
-defined to be coterminous with the <a href="#terms-root-temporal-extent">root temporal extent</a>.</p></div><div class="div3">
-<h4><a id="animation-vocabulary-set"></a>13.1.3 set</h4><p>The <code>set</code> element expresses one or more a discrete changes (animations) to be applied (targeted) to style property attributes
-of associated elements.</p><p>A <code>set</code> element may appear as either (1) a child of a
-<a href="#terms-content-element">content element</a> or a <a href="#layout-vocabulary-region"><code>region</code></a> element,
-referred to as <a href="#terms-inline-animation">inline animation</a>, or
-(2) a child of an <a href="#animation-vocabulary-animation">animation</a> element, referred to as
-<a href="#terms-out-of-line-animation">out-of-line animation</a>.
-In the former case, the parent of the <code>set</code> element is the associated element; in the latter
-case, any element that references the <code>set</code> element using an <code>animate</code> attribute is
-an associated element.</p><p>The <code>set</code> element accepts as its children zero or more
-elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group.</p><a id="elt-syntax-set"></a><table class="syntax"><caption>XML Representation – Element Information Item: set</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;set
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  fill = <a href="#animation-value-fill">&lt;fill&gt;</a>
-  repeatCount = <a href="#animation-value-repeatCount">&lt;repeatCount&gt;</a>
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*
-&lt;/set&gt;
-</pre></div>
-</td></tr></tbody></table><p>Style property attributes targeted by an <code>set</code> element are specified directly using
-attributes in the TT Style namespace or in a namespace that is not some TT namespace, where the single target animation (key) value
-adheres to the <a href="#animation-value-animationValueList">&lt;animationValueList&gt;</a> syntax, where each
-constituent <a href="#animation-value-animationValue">&lt;animationValue&gt;</a> adheres to the syntax of the specified
-attribute, and where exactly one constituent <a href="#animation-value-animationValue">&lt;animationValue&gt;</a> is specified.</p><p>If more than one constituent <a href="#animation-value-animationValue">&lt;animationValue&gt;</a> is specified, then all
-constituents other than the first must be ignored for the purpose of presentation processing, and must be considered an error for the
-purpose of validation processing.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In contrast with <a href="#svg11">[SVG 1.1]</a>, §19.2.13, a single <code>set</code> element, as defined here, may be used to
-perform discrete animations on a set of targeted style property attributes instead of being limited to targeting a single style property attribute.
-In <a href="#svg11">[SVG 1.1]</a>, this would require the use of multiple <code>set</code> elements rather than a single <code>set</code> element.</p></div><p>Except for the constraints or variations enumerated below, the semantics of the <code>set</code> element and its attributes
-enumerated above are defined to be those specified by <a href="#svg11">[SVG 1.1]</a>, §19.2.13:</p><ol class="enumar"><li><p>The attributes targeted by a <code>set</code> element and the discrete values to be applied to these attributes are
-specified by direct use of attributes in the TT Style namespace or in a namespace that is not a TT namespace (as opposed to using SVG's
-<code>attributeName</code> and <code>to</code> attributes).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, specifying <code>tts:color="red"</code> is
-considered equivalent to specifying <code>attributeName="tts:color"</code> and <code>to="red"</code> in <a href="#svg11">[SVG 1.1]</a>.</p></div></li><li><p>If no <code>fill</code> attribute is specified, then a <em>fill</em> value of <code>remove</code> applies.</p></li></ol><p>An example of using the <code>set</code> element to animate content
-styling is illustrated below:</p><a id="animation-vocabulary-set-example-1"></a><table class="example"><caption>Example Fragment – Content Style Animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;p dur="5s" tts:color="yellow"&gt;
-<span class="strong">&lt;set begin="1s" dur="1s" tts:color="red"/&gt;</span>
-<span class="strong">&lt;set begin="2s" dur="1s" tts:color="green"/&gt;</span>
-<span class="strong">&lt;set begin="3s" dur="1s" tts:color="red"/&gt;</span>
-Text with Flashing Colors!
-&lt;/p&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the foreground color of the content "Text
-with Flashing Colors!" is animated from yellow, to red, to green, to
-red, then back to yellow over a 5 second period.</p></div><p>An example of using the <code>set</code> element to animate region
-styling is illustrated below:</p><a id="animation-vocabulary-set-example-2"></a><table class="example"><caption>Example Fragment – Region Style Animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"
-    xmlns:ttp="http://www.w3.org/ns/ttml#parameter"
-    xmlns:tts="http://www.w3.org/ns/ttml#styling"
-    ttp:cellResolution="40 16"&gt;
-    &lt;head&gt;
-      &lt;layout&gt;
-	&lt;region xml:id="r1" timeContainer="seq"&gt;
-	  <span class="strong">&lt;set dur="10s" tts:origin=" 8c 14c"/&gt;</span>
-	  <span class="strong">&lt;set dur="2s"  tts:origin=" 2c  2c"/&gt;</span>
-	  <span class="strong">&lt;set dur="3s"  tts:origin=" 8c 14c"/&gt;</span>
-	  <span class="strong">&lt;set dur="2s"  tts:origin="14c  4c"/&gt;</span>
-	  <span class="strong">&lt;set dur="10s" tts:origin=" 8c 14c"/&gt;</span>
-	  &lt;style tts:extent="24c 2c"/&gt;
-	&lt;/region&gt;
-      &lt;/layout&gt;
-    &lt;/head&gt;
-    &lt;body region="r1"&gt;...&lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the <a href="#terms-root-container-region">root container region</a> is divided into a
-cell grid of 40 columns and 16 rows. A region, <code>r1</code>, with
-dimensions of 24 columns and 2 rows is then positioned within the
-<a href="#terms-root-container-region">root container region</a>, with its position varying over time in order to
-create an effect of moving the region, which may be desirable so as
-to avoid obscuring characters in an underlying video with captions.</p></div><p></p><table border="1" class="ednote" summary="Editorial note: Set Example Images"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Set Example Images</b></td><td align="right" valign="top">2013-08-25</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert animated SVG images of set examples.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the <code>set</code> element
-are based upon that defined by <a href="#svg11">[SVG 1.1]</a>,
-§19.2.13, which, in turn, is based upon <a href="#smil3">[SMIL 3.0]</a>, §12.</p></div></div></div><div class="div2">
-<h3><a id="animation-attribute-vocabulary"></a>13.2 Animation Attribute Vocabulary</h3><p>This section defines the <a href="#animation-attribute-animate"><b>13.2.1 animate</b></a> attribute used with <a href="#terms-content-element">content elements</a>
-and certain layout elements.</p><div class="div3">
-<h4><a id="animation-attribute-animate"></a>13.2.1 animate</h4><p>The <code>animate</code> attribute is used
-to reference one or more <a href="#animation-vocabulary-animate"><code>animate</code></a>
-or <a href="#animation-vocabulary-set"><code>set</code></a> elements
-each of which defines a specific <a href="#terms-out-of-line-animation">out-of-line animation</a>.</p><p>The <code>animate</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-br"><code>br</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li></ul><p>If specified, the value of an <code>animate</code> attribute must
-adhere to the <code>IDREFS</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§ 3.3.10, and, furthermore, each IDREF must reference an <a href="#animation-vocabulary-animate"><code>animate</code></a>
-or <a href="#animation-vocabulary-set"><code>set</code></a> element
-which has a <a href="#animation-vocabulary-animation"><code>animation</code></a> element as an ancestor.</p><p>A given IDREF must not appear more than one time in the value of an <code>animate</code>
-attribute.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See the specific element type definitions that permit use of the
-<code>animate</code> attribute.</p></div></div></div><div class="div2">
-<h3><a id="animation-value-expressions"></a>13.3 Animation Value Expressions</h3><p>Animation attribute values include the use of the following expressions:</p><ul><li><p><a href="#animation-value-animationValue"><b>13.3.1 &lt;animationValue&gt;</b></a></p></li><li><p><a href="#animation-value-animationValueList"><b>13.3.2 &lt;animationValueList&gt;</b></a></p></li><li><p><a href="#animation-value-calcMode"><b>13.3.3 &lt;calcMode&gt;</b></a></p></li><li><p><a href="#animation-value-fill"><b>13.3.4 &lt;fill&gt;</b></a></p></li><li><p><a href="#animation-value-keySplines"><b>13.3.5 &lt;keySplines&gt;</b></a></p></li><li><p><a href="#animation-value-keyTimes"><b>13.3.6 &lt;keyTimes&gt;</b></a></p></li><li><p><a href="#animation-value-repeatCount"><b>13.3.7 &lt;repeatCount&gt;</b></a></p></li></ul><div class="div3">
-<h4><a id="animation-value-animationValue"></a>13.3.1 &lt;animationValue&gt;</h4><p>An &lt;animationValue&gt; expression is used to specify the starting (initial), intermediate,
-or ending (final) of the attribute targeted by the animation.</p><a id="animationValue-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;animationValue&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;animationValue&gt;
-  : string
-</pre></div>
-</td></tr></tbody></table><p>The syntax of an &lt;animationValue&gt; expression must satisfy all syntax
-requirements that apply to the attribute targeted by the animation.</p><table border="1" class="ednote" summary="Editorial note: Improve Syntax of AnimationValue"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Improve Syntax of AnimationValue</b></td><td align="right" valign="top">2014-07-31</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Enhance detail of syntax of &lt;animationValue&gt; in order to prevent appearance of an unquoted or unescaped semicolon,
-which is used as a delimiter between animation values in &lt;animationValueList&gt;.</td></tr></table><p>The semantics of an &lt;animationValue&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.9.</p></div><div class="div3">
-<h4><a id="animation-value-animationValueList"></a>13.3.2 &lt;animationValueList&gt;</h4><p>An &lt;animationValueList&gt; expression is used to specify a list of animation values that sequentially
-apply to the attribute targeted by the animation, wherein each pair of values is separated by a SEMICOLON (U+003B) character
-optionally surrounded by linear white-space (LWSP) characters.</p><a id="animationValueList-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;animationValueList&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;animationValueList&gt;
-  : <a href="#animation-value-animationValue">&lt;animationValue&gt;</a> [ ";" <a href="#animation-value-animationValue">&lt;animationValue&gt;</a> ]*
-</pre></div>
-</td></tr></tbody></table><p>The syntax of an &lt;animationValue&gt; in an &lt;animationValueList&gt; expression must satisfy all syntax
-requirements that apply to the attribute targeted by the animation.</p><p>The semantics of an &lt;animationValueList&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.9.</p></div><div class="div3">
-<h4><a id="animation-value-calcMode"></a>13.3.3 &lt;calcMode&gt;</h4><p>A &lt;calcMode&gt; expression is used to control the interpolation mode of the animation.</p><a id="calcMode-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;calcMode&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;calcMode&gt;
-  : "discrete"
-  | "linear"
-  | "spline"
-</pre></div>
-</td></tr></tbody></table><p>The semantics of a &lt;calcMode&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.9.</p></div><div class="div3">
-<h4><a id="animation-value-fill"></a>13.3.4 &lt;fill&gt;</h4><p>A &lt;fill&gt; expression is used to determine effect of the animation after the active end of the animation.</p><a id="fill-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;fill&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;fill&gt;
-  : "freeze"
-  | "remove"
-</pre></div>
-</td></tr></tbody></table><p>The semantics of a &lt;fill&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.8.</p></div><div class="div3">
-<h4><a id="animation-value-keySplines"></a>13.3.5 &lt;keySplines&gt;</h4><p>An &lt;keySplines&gt; expression is used to specify a list of Bezier control points that control the pacing of an
-animation, wherein each pair of values is separated by a SEMICOLON (U+003B) character
-optionally surrounded by linear white-space (LWSP) characters.</p><a id="keySplines-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;keySplines&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;keySplines&gt;
-  : control [ lwsp? ";" lwsp? control ]*
-
-control
-  : x1 comma? y1 comma? x2 comma? y2
-
-x1, x2, y1, y2
-  : coordinate
-
-coordinate                                // 0 ≥ <em>value</em> ≥ 1
-  : whole
-  | whole "." fraction
-  | "." fraction
-
-whole, fraction
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-comma
-  : ","
-
-lwsp
-  : ( ' ' | '\t' | '\n' | '\r' )+
-</pre></div>
-</td></tr></tbody></table><p>The semantics of a &lt;keySplines&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.9, as apply to the <code>keySplines</code> attribute.</p></div><div class="div3">
-<h4><a id="animation-value-keyTimes"></a>13.3.6 &lt;keyTimes&gt;</h4><p>An &lt;keyTimes&gt; expression is used to specify a list of relative time values that control the pacing of an
-animation, wherein each pair of values is separated by a SEMICOLON (U+003B) character
-optionally surrounded by linear white-space (LWSP) characters.</p><a id="keyTimes-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;keyTimes&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;keyTimes&gt;
-  : time [ lwsp? ";" lwsp? time ]*
-
-time                                // 0 ≥ <em>value</em> ≥ 1
-  : whole
-  | whole "." fraction
-  | "." fraction
-
-whole, fraction
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-lwsp
-  : ( ' ' | '\t' | '\n' | '\r' )+
-</pre></div>
-</td></tr></tbody></table><p>The semantics of a &lt;keyTimes&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.9, as apply to the <code>keyTimes</code> attribute.</p></div><div class="div3">
-<h4><a id="animation-value-repeatCount"></a>13.3.7 &lt;repeatCount&gt;</h4><p>A &lt;repeatCount&gt; expression is used to determine the number of iterations of a repeated animation.</p><a id="repeatCount-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;repeatCount&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;repeatCount&gt;
-  : count
-  | "indefinite"
-
-count:
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+                       // <em>value</em> &gt; 0
-</pre></div>
-</td></tr></tbody></table><p>The semantics of a &lt;repeatCount&gt; expression are those defined by
-<a href="#svg11">[SVG 1.1]</a>, §19.2.8.</p></div></div></div><div class="div1">
-<h2><a id="metadata"></a>14 Metadata</h2><p>This section specifies the <em>metadata</em> matter of the core
-vocabulary catalog, where
-metadata is to be understood as a separable layer of information that applies to
-parameters, content,
-style, layout, timing, and even metadata itself, where the information
-represented by metadata takes one of two forms: (1) metadata defined by this
-specification for standardized use in a <a href="#terms-document-instance">document instance</a>, and (2) arbitrary
-metadata defined outside of the scope of this specification, whose use and
-semantics depend entirely upon an application's use of TTML Content.</p><div class="div2">
-<h3><a id="metadata-element-vocabulary"></a>14.1 Metadata Element Vocabulary</h3><p>The <a href="#metadata-vocabulary-metadata"><b>14.1.1 metadata</b></a> element serves as
-a generic container element for grouping metadata information.</p><p>In addition, the following elements, all defined in the TT Metadata Namespace,
-provide standard representations for metadata that is expected to be commonly
-used in a <a href="#terms-document-instance">document instance</a>:
-</p><ul><li><p><a href="#metadata-vocabulary-actor"><b>14.1.2 ttm:actor</b></a></p></li><li><p><a href="#metadata-vocabulary-agent"><b>14.1.3 ttm:agent</b></a></p></li><li><p><a href="#metadata-vocabulary-copyright"><b>14.1.4 ttm:copyright</b></a></p></li><li><p><a href="#metadata-vocabulary-desc"><b>14.1.5 ttm:desc</b></a></p></li><li><p><a href="#metadata-vocabulary-item"><b>14.1.6 ttm:item</b></a></p></li><li><p><a href="#metadata-vocabulary-name"><b>14.1.7 ttm:name</b></a></p></li><li><p><a href="#metadata-vocabulary-title"><b>14.1.8 ttm:title</b></a></p></li></ul><div class="div3">
-<h4><a id="metadata-vocabulary-metadata"></a>14.1.1 metadata</h4><p>The <code>metadata</code> element functions as a generic container for metadata
-information.</p><p>Metadata information may be expressed with a <code>metadata</code> element by specifying
-(1) one or more metadata attributes or foreign namespace attributes on the <code>metadata</code> element,
-(2) one or more metadata item or foreign namespace child elements,
-(3) one or more <a href="#embedded-content-vocabulary-data"><code>data</code></a> child elements, or
-(4) a combination of the preceding.</p><a id="elt-syntax-metadata"></a><table class="syntax"><caption>XML Representation – Element Information Item: metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;metadata
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> (<a href="#element-vocab-group-data"><code>Data.class</code></a>|{<em>any element in TT Metadata namespace</em>}|{<em>any element not in any TT namespace</em>})*
-&lt;/metadata&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The meaning of a specific metadata item must be evaluated in the
-context where it appears. The core vocabulary catalog permits an
-arbitrary number of <code>metadata</code> element children on any
-<a href="#terms-content-element">content element</a> type. See specific element
-vocabulary definitions for any constraints that apply to such
-usage.</p></div><p>The use of document metadata is illustrated by the following example.</p><a id="metadata-vocabulary-metadata-example-1"></a><table class="example"><caption>Example Fragment – Document Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;head&gt;
-  &lt;metadata xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-    &lt;ttm:title&gt;Document Metadata Example&lt;/ttm:title&gt;
-    &lt;ttm:desc&gt;This document employs document metadata.&lt;/ttm:desc&gt;
-  &lt;/metadata&gt;
-&lt;/head&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p><p>The use of element metadata is illustrated by the following example.</p><a id="metadata-vocabulary-metadata-example-2"></a><table class="example"><caption>Example Fragment – Element Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;div&gt;
-  &lt;metadata xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-    &lt;ttm:title&gt;Chapter 6 – Sherlock Holmes Gives a Demonstration&lt;/ttm:title&gt;
-    &lt;ttm:desc&gt;Holmes shows Watson how the murderer entered the window.&lt;/ttm:desc&gt;
-  &lt;/metadata&gt;
-&lt;/div&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p><p>The use of metadata attribute items is illustrated by the following example.</p><a id="metadata-vocabulary-metadata-example-3"></a><table class="example"><caption>Example Fragment – Foreign Metadata Attribute Items</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;div xmlns:ext="http://example.org/ttml#metadata"&gt;
-  &lt;metadata ext:ednote="remove this division prior to publishing"/&gt;
-&lt;/div&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a global attribute from a foreign (external)
-namespace is used to express a metadata attribute that applies
-semantically to the containing <code>div</code> element. Note that the
-attribute may also be expressed directly on the <code>div</code> element;
-however, in this case the author wishes to segregate certain metadata
-attributes by expressing them indirectly on <code>metadata</code>
-elements.</p></div><p></p><p>The use of foreign element metadata is illustrated by the following example.</p><a id="metadata-vocabulary-metadata-example-4"></a><table class="example"><caption>Example Fragment – Foreign Element Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;metadata
-  xmlns:dc="http://purl.org/dc/elements/1.1/"
-  xmlns:dcterms="http://purl.org/dc/terms/"
-  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
-  &lt;dc:title&gt;Foreign Element Metadata Example&lt;/dc:title&gt;
-  &lt;dc:description&gt;Express metadata using elements in foreign namespace.&lt;/dc:description&gt;
-  &lt;dc:format xsi:type="dcterms:IMT"&gt;application/ttml+xml&lt;/dc:format&gt;
-&lt;/metadata&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a number of elements defined by the Dublin
-Core metadata vocabulary are used to express document level metadata.</p></div><p></p></div><div class="div3">
-<h4><a id="metadata-vocabulary-actor"></a>14.1.2 ttm:actor</h4><p>The <code>ttm:actor</code> element is used to link the definition of a (role-based) character
-agent with another agent that portrays the character.</p><a id="elt-syntax-metadata-actor"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:actor</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:actor
-  <span class="reqattr">agent</span> = IDREF
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> EMPTY
-&lt;/ttm:actor&gt;
-</pre></div>
-</td></tr></tbody></table><p>The <code>agent</code> attribute of a <code>ttm:actor</code> element must
-reference a <em>significant</em> <code>ttm:agent</code> element that denotes the agent
-acting the part of a character.</p><p>An example of the <code>ttm:actor</code> element is shown above in
-<a href="#metadata-vocabulary-agent-example-1"><b>Example Fragment – Agent Metadata</b></a>.</p></div><div class="div3">
-<h4><a id="metadata-vocabulary-agent"></a>14.1.3 ttm:agent</h4><p>The <code>ttm:agent</code> element is used to define an agent for the purpose of associating
-content information with an agent who is involved in the production or expression of that content.</p><p>The <code>ttm:agent</code> element accepts as its children zero or more <code>ttm:name</code> elements followed by
-zero or one <code>ttm:actor</code> element.</p><p>At least one <code>ttm:name</code> element child should be specified that expresses a name for the
-agent, whether it be the name of a person, character, group, or organization.</p><a id="elt-syntax-metadata-agent"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:agent</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:agent
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <span class="reqattr">type</span> = (<em>person</em>|<em>character</em>|<em>group</em>|<em>organization</em>|<em>other</em>)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#metadata-vocabulary-name">ttm:name</a>*, <a href="#metadata-vocabulary-actor">ttm:actor</a>?
-&lt;/ttm:agent&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>type</code> attribute must be specified on each <code>ttm:agent</code> element, and,
-if specified, must have one of the following values:</p><ul><li><p><code>person</code></p></li><li><p><code>character</code></p></li><li><p><code>group</code></p></li><li><p><code>organization</code></p></li><li><p><code>other</code></p></li></ul><p>If the value of the <code>type</code> attribute is <code>character</code>, then the
-<code>ttm:agent</code> element instance should specify a <code>ttm:actor</code> child that
-specifies the agent that plays the role of the actor.</p><p>A <code>ttm:agent</code> metadata item is considered to be significant only
-when specified as a child of the <code>head</code> element or as a child of a
-<code>metadata</code> element child of the <code>head</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <code>ttm:agent</code> element instance is typically referenced using a <code>ttm:agent</code>
-attribute on a <a href="#terms-content-element">content element</a> type.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>If a character agent is played by multiple actors, then multiple character
-agents may be specified (and referenced) wherein different definitions of the
-character specify different actors.</p></div><p>The use of agent metadata is illustrated by the following example.</p><a id="metadata-vocabulary-agent-example-1"></a><table class="example"><caption>Example Fragment – Agent Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="en" xmlns="http://www.w3.org/ns/ttml" xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-  &lt;head&gt;
-    <span class="strong">&lt;ttm:agent xml:id="connery" type="person"&gt;</span>
-      &lt;ttm:name type="family"&gt;Connery&lt;/ttm:name&gt;
-      &lt;ttm:name type="given"&gt;Thomas Sean&lt;/ttm:name&gt;
-      &lt;ttm:name type="alias"&gt;Sean&lt;/ttm:name&gt;
-      &lt;ttm:name type="full"&gt;Sir Thomas Sean Connery&lt;/ttm:name&gt;
-    <span class="strong">&lt;/ttm:agent&gt;</span>
-    <span class="strong">&lt;ttm:agent xml:id="bond" type="character"&gt;</span>
-      &lt;ttm:name type="family"&gt;Bond&lt;/ttm:name&gt;
-      &lt;ttm:name type="given"&gt;James&lt;/ttm:name&gt;
-      &lt;ttm:name type="alias"&gt;007&lt;/ttm:name&gt;
-      &lt;ttm:actor agent="connery"/&gt;
-    <span class="strong">&lt;/ttm:agent&gt;</span>
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;div&gt;
-      ...  
-      &lt;p <span class="strong">ttm:agent="bond"</span>&gt;I travel, a sort of licensed troubleshooter.&lt;/p&gt;
-      ...  
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, two agents, a real (person) agent, Sean
-Connery, and a fictitious (character) agent, James Bond, are defined,
-where the latter is linked to the former by means of the a
-<code>ttm:actor</code> element. A reference is then made from content (the
-<code>p</code> element) to the character agent associated with
-(responsible for producing) that content. Note that in this example
-the <code>ttm:agent</code> metadata items are specified as immediate
-children of the document's <code>head</code> element rather than being
-placed in a container <code>metadata</code> element.</p></div></div><div class="div3">
-<h4><a id="metadata-vocabulary-copyright"></a>14.1.4 ttm:copyright</h4><p>The <code>ttm:copyright</code> element is used to express a human-readable copyright that
-applies to some scoping level.</p><p>A copyright statement that applies to a document as a whole should appear as a
-child of the <code>head</code> element.</p><a id="elt-syntax-metadata-copyright"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:copyright</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:copyright
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:copyright&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>No specific use of the <code>ttm:copyright</code> element is defined by this specification.</p></div></div><div class="div3">
-<h4><a id="metadata-vocabulary-desc"></a>14.1.5 ttm:desc</h4><p>The <code>ttm:desc</code> element is used to express a human-readable description of
-a specific element instance.</p><a id="elt-syntax-metadata-desc"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:desc</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:desc
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:desc&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>No specific use of the <code>ttm:desc</code> element is defined by this specification.</p></div><p>Examples of the <code>ttm:desc</code> element are shown above in
-<a href="#metadata-vocabulary-metadata-example-1"><b>Example Fragment – Document Metadata</b></a> and
-<a href="#metadata-vocabulary-metadata-example-2"><b>Example Fragment – Element Metadata</b></a>.</p></div><div class="div3">
-<h4><a id="metadata-vocabulary-item"></a>14.1.6 ttm:item</h4><p>The <code>ttm:item</code> element is used to express arbitrary named metadata items.</p><p>The <code>ttm:item</code> element accepts one of the following two content models:
-(1) one or more text nodes (i.e., <code>#PCDATA</code>) or
-(2) zero or more nested <a href="#metadata-vocabulary-item">ttm:item</a> elements.</p><a id="elt-syntax-metadata-item"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:item</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:item
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <span class="reqattr">name</span> = <a href="#metadata-value-item-name">&lt;item-name&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA | <a href="#metadata-vocabulary-item">ttm:item</a>*
-&lt;/ttm:item&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>name</code> attribute must be specified to identify the name of the item, the value of which must adhere to
-an <a href="#metadata-value-item-name">&lt;item-name&gt;</a> value expression.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>No general constraint is placed on the appearance of multiple named metadata items that specify the same name; however,
-the definition of a specific named item may further constrain the context of use as well as the potential appearance of multiple items that share the same name.</p></div><p>The value of a named metadata item is
-(1) empty if the element has no child text or element nodes,
-(2) the character content of the <code>ttm:item</code> element when that element's children consists solely of text nodes, or
-(3) a collection of named metadata sub-items.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The definition of a particular named item will typically constrain the set of permitted values. Furthermore, it may
-specify that a particular value is implied in the absence of a specified value.</p></div><p>The use of a named metadata item is illustrated by the following example, which shows the use of a named metadata item
-in order to associate a <a href="#terms-simple-data-embedding">simple data embedding</a> with an original file name.</p><a id="metadata-vocabulary-item-example-1"></a><table class="example"><caption>Example Fragment – Named Metadata Item</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;image&gt;
-  &lt;source&gt;
-    &lt;data type="image/png"&gt;
-      <span class="strong">&lt;ttm:item name="originalFileName" xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;image.png&lt;/ttm:item&gt;</span>
-      &lt;chunk length="119"&gt;
-        iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8
-        YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAMSURBVBhXY2BgYAAAAAQAAVzN/2kAAAAASUVORK5CYII=
-      &lt;/chunk&gt;
-    &lt;/data&gt;
-  &lt;/source&gt;
-&lt;/image&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p></p><div class="note"><p class="prefix"><b>Note:</b></p><p>The above example makes use of a single <a href="#embedded-content-vocabulary-chunk">chunk</a> element in order
-to include a <code>ttm:item</code> element as a child of the <a href="#embedded-content-vocabulary-data">data</a> element;
-i.e., if the encoded image bytes had been included directly as #PCDATA in the <a href="#embedded-content-vocabulary-data">data</a> element,
-then it would not have been possible to include the <code>ttm:item</code> child element. See the supported content models on the
-<a href="#embedded-content-vocabulary-data">data</a> element for more information.</p></div></div><div class="div3">
-<h4><a id="metadata-vocabulary-name"></a>14.1.7 ttm:name</h4><p>The <code>ttm:name</code> element is used to specify a name of a person, character,
-group, or organization.</p><a id="elt-syntax-metadata-name"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:name</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:name
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <span class="reqattr">type</span> = (<em>full</em>|<em>family</em>|<em>given</em>|<em>alias</em>|<em>other</em>)
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:name&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>type</code> attribute must be specified on each <code>ttm:name</code> element, and,
-if specified, must have one of the following values:</p><ul><li><p><code>full</code></p></li><li><p><code>family</code></p></li><li><p><code>given</code></p></li><li><p><code>alias</code></p></li><li><p><code>other</code></p></li></ul><p>The relationship between the type of a name and the syntactic expression of the name
-is not defined by this specification.</p><p>Two examples of the <code>ttm:name</code> element are shown above in
-<a href="#metadata-vocabulary-agent-example-1"><b>Example Fragment – Agent Metadata</b></a>.</p></div><div class="div3">
-<h4><a id="metadata-vocabulary-title"></a>14.1.8 ttm:title</h4><p>The <code>ttm:title</code> element is used to express a human-readable title of
-a specific element instance.</p><a id="elt-syntax-metadata-title"></a><table class="syntax"><caption>XML Representation – Element Information Item: ttm:title</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:title
-  <a href="#content-attribute-condition">condition</a> = <a href="#content-value-condition">&lt;condition&gt;</a>
-  <a href="#content-attribute-xml-id">xml:id</a> = ID
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:title&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>No specific use of the <code>ttm:title</code> element is defined by this specification.</p></div><p>Examples of the <code>ttm:title</code> element are shown above in
-<a href="#metadata-vocabulary-metadata-example-1"><b>Example Fragment – Document Metadata</b></a> and
-<a href="#metadata-vocabulary-metadata-example-2"><b>Example Fragment – Element Metadata</b></a>.</p></div></div><div class="div2">
-<h3><a id="metadata-attribute-vocabulary"></a>14.2 Metadata Attribute Vocabulary</h3><p>This section specifies the following attributes in the TT Metadata Namespace
-for use with the <code>metadata</code> element and with certain
-<a href="#terms-content-element">content element</a> types:</p><ul><li><p><a href="#metadata-attribute-agent"><b>14.2.1 ttm:agent</b></a></p></li><li><p><a href="#metadata-attribute-role"><b>14.2.2 ttm:role</b></a></p></li></ul><div class="issue"><p class="prefix"><a id="issue-358"></a><b>Issue (issue-358):</b></p><p class="prefix"><b>Document Sequencing</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/358">http://www.w3.org/AudioVideo/TT/tracker/issues/358</a></p><p>Add <code>ttm:sequenceIdentifier</code> or <code>ttm:sequenceNumber</code> or both if unavoidable.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p></p><div class="issue"><p class="prefix"><a id="issue-361"></a><b>Issue (issue-361):</b></p><p class="prefix"><b>Media Timestamp Correlation</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/361">http://www.w3.org/AudioVideo/TT/tracker/issues/361</a></p><p>Add <code>ttm:mediaTimestamp</code> to support media synchronization.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>Only certain metadata item attributes may be used with <a href="#terms-content-element">content element</a>. See
-the definitions of <a href="#terms-content-element">content elements</a> to determine permissible usage.</p></div><div class="div3">
-<h4><a id="metadata-attribute-agent"></a>14.2.1 ttm:agent</h4><p>The <code>ttm:agent</code> attribute takes an <code>IDREFS</code>
-value, and is used with certain <a href="#terms-content-element">content elements</a> to designate the
-agents that perform or are
-involved in the performance of the content.</p><p>If specified, a <code>ttm:agent</code> attribute must reference <em>significant</em>
-<code>ttm:agent</code> element instances.</p><p>The same IDREF, <em>ID</em>, should not appear more than once in the value of a <code>ttm:agent</code> attribute.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This constraint is intended to discourage the use of redundant agent references.</p></div><p>An example of the <code>ttm:agent</code> attribute is shown above in
-<a href="#metadata-vocabulary-agent-example-1"><b>Example Fragment – Agent Metadata</b></a>.</p></div><div class="div3">
-<h4><a id="metadata-attribute-role"></a>14.2.2 ttm:role</h4><p>The <code>ttm:role</code> attribute may be used by a content author
-to express
-the roles, functions, or characteristics
-of some <a href="#terms-content-element">content element</a> that is so labeled.</p><div class="issue"><p class="prefix"><a id="issue-25"></a><b>Issue (issue-25):</b></p><p class="prefix"><b>Parameterized Roles</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/25">http://www.w3.org/AudioVideo/TT/tracker/issues/25</a></p><p>Consider supporting parameterized roles to increase CEA 708 interoperability.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>If specified, the value of this attribute must adhere to the following
-syntax, where
-the syntactic element <em>S</em> must adhere to production
-[3] <code>S</code> as defined by <a href="#xml10">[XML 1.0]</a>&nbsp;§
-2.3:</p><a id="metadata-attribute-role-syntax"></a><table class="syntax"><caption>Syntax Representation – ttm:role</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttm:role
-  role ( <em>S</em> role )*
-
-role
-  : "action"
-  | "caption"
-  | "description"
-  | "dialog"
-  | "expletive"
-  | "kinesic"
-  | "lyrics"
-  | "music"
-  | "narration"
-  | "quality"
-  | "sound"
-  | "source"
-  | "suppressed"
-  | "reproduction"
-  | "thought"
-  | "title"
-  | "transcription"
-  | extension-role
-
-extension-role
-  : "x-" token-char+
-
-token-char
-  : { XML NameChar }    // XML 1.1 Production [4a]
-</pre></div>
-</td></tr></tbody></table><p>The same <code>role</code> token, <em>R</em>, should not appear more than once in the value of a <code>ttm:role</code> attribute.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This constraint is intended to discourage the use of redundant role tokens.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>All values of <code>ttm:role</code> that do not start with the prefix
-<code>x-</code> are reserved for future standardization.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>If using a custom <code>x-</code> prefixed form of <code>ttm:role</code>, it
-is recommended that an organization unique infix be used as well in order to
-prevent collisions. For example, <code>x-example-org-custom-role</code>. Furthermore,
-a registry for role values is available at
-<a href="http://www.w3.org/wiki/TTML/RoleRegistry">http://www.w3.org/wiki/TTML/RoleRegistry</a>
-in order to promote interoperability and collision avoidance.</p></div></div></div><div class="div2">
-<h3><a id="metadata-value-expressions"></a>14.3 Metadata Value Expressions</h3><p>Metadata vocabulary may make use of the following expressions:</p><ul><li><p><a href="#metadata-value-item-name"><b>14.3.1 &lt;item-name&gt;</b></a></p></li></ul><div class="div3">
-<h4><a id="metadata-value-item-name"></a>14.3.1 &lt;item-name&gt;</h4><p>An &lt;item-name&gt; expression is used to specify the name of a metadata item expressed with a
-<a href="#metadata-vocabulary-item">ttm:item</a> element.</p><a id="item-name-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;item-name&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;item-name&gt;
-  : <a href="#metadata-value-named-item">&lt;named-item&gt;</a>
-  | <a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>
-</pre></div>
-</td></tr></tbody></table><p>If an item name expression takes the form of a qualified name (<a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>), 
-then the prefix of that qualified name must have been declared in a namespace declaration as specified by <a href="#xmlns10">[XML Namespaces 1.0]</a>.</p><p>All values of &lt;item-name&gt; that do not take the form of qualified name (<a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>)
-are reserved for future standardization by the W3C.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>It is intended that all item names defined by this specification are unqualified (without a prefix), whereas those defined by
-external specifications are qualified (with a prefix).</p></div></div><div class="div3">
-<h4><a id="metadata-value-named-item"></a>14.3.2 &lt;named-item&gt;</h4><p>A &lt;named-item&gt; value is one of an enumerated collection of named metadata items associated with a value by
-a <a href="#metadata-vocabulary-item"><code>ttm:item</code></a> element.</p><a id="named-item-value-expression-syntax"></a><table class="syntax"><caption>Syntax Representation – &lt;named-item&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;named-item&gt;
-  : cea608CaptionService
-  | cea608Channel
-  | cea608ContentAdvisory
-  | cea608CopyAndRedistributionControl
-  | cea608FieldStart
-  | cea608ProgramName
-  | cea608ProgramType
-  | cea708EasyReader
-  | cea708FCCMinimum
-  | cea708ServiceNumber
-  | cea708TransformMode
-  | cea708TransformOrigin
-  | cea708TransformTimingThreshold
-  | creationCountryOfOrigin
-  | creationDate
-  | creationSystem
-  | editor
-  | editorContact
-  | maximumCharactersPerRow
-  | originalEpisodeTitle
-  | originalFileName
-  | originalProgramTitle
-  | publisher
-  | readingSpeed
-  | revisionDate
-  | revisionNumber
-  | sourceFormat
-  | subtitleCount
-  | subtitleReferenceCode
-  | targetAspectRatio
-  | targetActiveFormatDescriptor
-  | targetBarData
-  | targetFormat
-  | translatedEpisodeTitle
-  | translatedProgramTitle
-  | translator
-  | translatorContact
-</pre></div>
-</td></tr></tbody></table><p></p><div class="issue"><p class="prefix"><a id="issue-328"></a><b>Issue (issue-328):</b></p><p class="prefix"><b>Alternate Text Metadata</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/328">http://www.w3.org/AudioVideo/TT/tracker/issues/328</a></p><p>Add named item to handle <code>ittm:altText</code>.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p></p><table border="1" class="ednote" summary="Editorial note: Elaborate Named Items"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Elaborate Named Items</b></td><td align="right" valign="top">2014-11-26</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Further specify the value syntax of certain named items, e.g., by adding external document references (CEA608) or by defining specific value syntax.</td></tr></table><dl><dt class="label"><a id="named-item-cea608CaptionService"></a><code>cea608CaptionService</code></dt><dd><p>A string that expresses the field and channel mapping of a CEA-608 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-cea608Channel"></a><code>cea608Channel</code></dt><dd><p>A string that expresses the channel code of a CEA-608 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-cea608ContentAdvisory"></a><code>cea608ContentAdvisory</code></dt><dd><p>A string that expresses the content advisory packet information of a CEA-608 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-cea608CopyAndRedistributionControl"></a><code>cea608CopyAndRedistributionControl</code></dt><dd><p>A string that expresses the copy and redistribution control packet information of a CEA-608 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-cea608FieldStart"></a><code>cea608FieldStart</code></dt><dd><p>An integer that expresses the field start of a CEA-608 caption service, where the value
-is either 1 or 2.</p></dd><dt class="label"><a id="named-item-cea608ProgramName"></a><code>cea608ProgramName</code></dt><dd><p>A string that expresses the program name of a CEA-608 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-cea608ProgramType"></a><code>cea608ProgramType</code></dt><dd><p>A string that expresses the program type code of a CEA-608 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-cea708EasyReader"></a><code>cea708EasyReader</code></dt><dd><p>A boolean that expresses whether a CEA-708 caption service is characterized for use with an easy reader, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#boolean">xsd:boolean</a>.</p></dd><dt class="label"><a id="named-item-cea708FCCMinimum"></a><code>cea708FCCMinimum</code></dt><dd><p>A boolean that expresses whether a CEA-708 caption service is characterized as conforming to minimum FCC decoder requirements, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#boolean">xsd:boolean</a>.</p></dd><dt class="label"><a id="named-item-cea708ServiceNumber"></a><code>cea708ServiceNumber</code></dt><dd><p>An integer that expresses the service number of a CEA-708 caption service, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#positiveInteger">xsd:positiveInteger</a> and is less than 32.</p></dd><dt class="label"><a id="named-item-cea708TransformMode"></a><code>cea708TransformMode</code></dt><dd><p>One of the token values <code>enhanced</code> or <code>preserved</code>.</p></dd><dt class="label"><a id="named-item-cea708TransformOrigin"></a><code>cea708TransformOrigin</code></dt><dd><p>Either the token <code>none</code> or an <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>,
-where the latter expresses a CEA-708 transformation source format.</p></dd><dt class="label"><a id="named-item-cea708TransformTimingThreshold"></a><code>cea708TransformTimingThreshold</code></dt><dd><p>A real number that expresses a threshold parameter used to suppress the inclusion of temporary timed states when
-transforming amongst a CEA-708 caption service and a <a href="#terms-timed-text-content-document">timed text content document</a>,
-where the value adheres to <a href="http://www.w3.org/TR/xmlschema-2/#boolean">xsd:float</a>.</p></dd><dt class="label"><a id="named-item-creationCountryOfOrigin"></a><code>creationCountryOfOrigin</code></dt><dd><p>A string that expresses a the country or origin code associated with this document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-creationDate"></a><code>creationDate</code></dt><dd><p>A date that expresses the creation date of this document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#date">xsd:date</a>.</p></dd><dt class="label"><a id="named-item-creationSystem"></a><code>creationSystem</code></dt><dd><p>A free form string expressing the software and version used to create the document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-editor"></a><code>editor</code></dt><dd><p>A string that expresses the name of one or more editors, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-editorContact"></a><code>editorContact</code></dt><dd><p>A string that expresses the contact details of one or more editors, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-maximumCharactersPerRow"></a><code>maximumCharactersPerRow</code></dt><dd><p>A non-negative integer that expresses the maximum number of characters per row (line) used in this document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#nonNegativeInteger">xsd:nonNegativeInteger</a>.</p></dd><dt class="label"><a id="named-item-originalEpisodeTitle"></a><code>originalEpisodeTitle</code></dt><dd><p>A string that expresses the episode title in the original language, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-originalFileName"></a><code>originalFileName</code></dt><dd><p>A string that expresses the original file name of a <a href="#terms-data-resource">data resource</a>, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p><p>A <code>originalFileName</code> item may specified as a descendant element of a <a href="#embedded-content-vocabulary-data">data</a> element
-in order to associate the <a href="#terms-data-resource">data resource</a> represented by that <a href="#embedded-content-vocabulary-data">data</a> element
-with an original file name.</p></dd><dt class="label"><a id="named-item-originalProgramTitle"></a><code>originalProgramTitle</code></dt><dd><p>A string that expresses the program title in the original language, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-publisher"></a><code>publisher</code></dt><dd><p>A string that expresses the name of one or more publishers, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-readingSpeed"></a><code>readingSpeed</code></dt><dd><p>An integer that expresses the reading speed in words per minute, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#positiveInteger">xsd:positiveInteger</a>.</p></dd><dt class="label"><a id="named-item-revisionDate"></a><code>revisionDate</code></dt><dd><p>A date that expresses the last revision date of this document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#date">xsd:date</a>.</p></dd><dt class="label"><a id="named-item-revisionNumber"></a><code>revisionNumber</code></dt><dd><p>A non-negative integer that expresses the revision number of this document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#nonNegativeInteger">xsd:nonNegativeInteger</a>.</p></dd><dt class="label"><a id="named-item-sourceFormat"></a><code>sourceFormat</code></dt><dd><p>A string that expresses the source subtitle or caption format from which the <a href="#terms-enclosing-document-instance">enclosing document instance</a>
-was transformed, where the value adheres to either <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-or <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>.</p></dd><dt class="label"><a id="named-item-subtitleCount"></a><code>subtitleCount</code></dt><dd><p>A non-negative integer that expresses the number of subtitles (captions) in this document, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#nonNegativeInteger">xsd:nonNegativeInteger</a>.</p></dd><dt class="label"><a id="named-item-subtitleReferenceCode"></a><code>subtitleReferenceCode</code></dt><dd><p>A string that expresses a subtitle reference code, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-targetAspectRatio"></a><code>targetAspectRatio</code></dt><dd><p>A string that expresses the target video's aspect ratio, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-targetActiveFormatDescriptor"></a><code>targetActiveFormatDescriptor</code></dt><dd><p>A string that expresses the target video's active format descriptor, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-targetBarData"></a><code>targetBarData</code></dt><dd><p>A string that expresses the target video's bar data, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-targetFormat"></a><code>targetFormat</code></dt><dd><p>A string that expresses the target subtitle or caption format to which the <a href="#terms-enclosing-document-instance">enclosing document instance</a>
-is intended to be transformed, where the value adheres to either <a href="http://www.w3.org/TR/xmlschema-2/#token">xsd:token</a>
-or <a href="http://www.w3.org/TR/xmlschema-2/#anyURI">xsd:anyURI</a>.</p></dd><dt class="label"><a id="named-item-translatedEpisodeTitle"></a><code>translatedEpisodeTitle</code></dt><dd><p>A string that expresses the episode title in the translated (local) language, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-translatedProgramTitle"></a><code>translatedProgramTitle</code></dt><dd><p>A string that expresses the program title in the translated (local) language, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-translator"></a><code>translator</code></dt><dd><p>A string that expresses the name of one or more translators, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd><dt class="label"><a id="named-item-translatorContact"></a><code>translatorContact</code></dt><dd><p>A string that expresses the contact details of one or more translators, where the value
-adheres to <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>.</p></dd></dl></div></div></div></div><div class="back"><div class="div1">
-<h2><a id="concrete-encoding"></a>A Concrete Encoding</h2><p><em>This appendix is normative.</em></p><p>In the absence of other requirements, a <a href="#terms-document-instance">document instance</a> should be concretely encoded as a
-well-formed XML 1.0 <a href="#xml10">[XML 1.0]</a> document using the UTF-8 character encoding.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When using XML 1.0 <a href="#xml10">[XML 1.0]</a> as the concrete encoding of TTML, only the following named character entities are defined:
-<code>&amp;amp;</code>, <code>&amp;apos;</code>, <code>&amp;gt;</code>, <code>&amp;lt;</code>, and <code>&amp;quot;</code>.</p></div><div class="issue"><p class="prefix"><a id="issue-360"></a><b>Issue (issue-360):</b></p><p class="prefix"><b>Support Content Encoding</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/360">http://www.w3.org/AudioVideo/TT/tracker/issues/360</a></p><p>Specify preference to use of gzip content encoding for compressed delivery in the case that client indicates it accepts encoding.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div></div><div class="div1">
-<h2><a id="reduced-infoset"></a>B Reduced XML Infoset</h2><p><em>This appendix is normative.</em></p><p>For the purposes of this specification, a <a href="#terms-reduced-xml-infoset">reduced xml infoset</a> is
-an XML Information Set <a href="#infoset">[XML InfoSet]</a> that consists of only the following information items
-and information item properties:</p><div class="div2">
-<h3><a id="reduced-infoset-document"></a>B.1 Document Information Item</h3><ul><li><p><code>[document element]</code></p></li></ul></div><div class="div2">
-<h3><a id="reduced-infoset-element"></a>B.2 Element Information Item</h3><ul><li><p><code>[namespace URI]</code></p></li><li><p><code>[local name]</code></p></li><li><p><code>[children]</code></p></li><li><p><code>[attributes]</code></p></li></ul><p>Child information items <code>[children]</code> are reduced to only
-<a href="#terms-element-information-item">element information items</a> and
-<a href="#terms-character-information-item">character information items</a>.</p></div><div class="div2">
-<h3><a id="reduced-infoset-attribute"></a>B.3 Attribute Information Item</h3><ul><li><p><code>[namespace URI]</code></p></li><li><p><code>[local name]</code></p></li><li><p><code>[normalized value]</code></p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>See also <a href="#terms-attribute-information-item">attribute information item</a>.</p></div></div><div class="div2">
-<h3><a id="reduced-infoset-character"></a>B.4 Character Information Item</h3><ul><li><p><code>[character code]</code></p></li></ul><p>Contiguous character information items are not required to be represented distinctly,
-but may be aggregated (chunked) into a sequence of character codes (i.e., a character string).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See also <a href="#terms-character-information-item">character information item</a>.</p></div></div></div><div class="div1">
-<h2><a id="schemas"></a>C Schemas</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the following schemas for use with
-<a href="#terms-document-instance">document instances</a>:</p><ul><li><p>Relax NG, Compact Syntax (RNC) Schema</p></li><li><p>XML Schema Definition (XSD) Schema</p></li></ul><p>In any case where a schema specified by this appendix differs from the
-normative definitions of document type, element type, or attribute type
-as defined by the body of this specification, then the body of this
-specification takes precedence.</p><div class="div2">
-<h3><a id="ttml-schema-rnc"></a>C.1 Relax NG Compact (RNC) Schema</h3><p>A Relax NG Compact Syntax (RNC) <a href="#rng">[RELAX NG]</a> based schema
-for TTML Content is available at <a href="rnc/schema.zip">ZIP
-Archive</a>. This schema is to be considered non-normative for the purpose of defining the validity
-of Timed Text Markup Language content as defined by this specification.
-In particular, the formal validity of TTML Content
-is defined by <a href="#conformance-content"><b>3.1 Document Conformance</b></a>.</p></div><div class="div2">
-<h3><a id="ttml-schema-xsd"></a>C.2 XML Schema Definition (XSD) Schema</h3><p>A W3C XML Schema Definition (XSD) <a href="#xsd-1">[XML Schema Part 1]</a> based schema
-for TTML Content is available at <a href="xsd/schema.zip">ZIP
-Archive</a>. This schema is to be considered non-normative for the purpose of defining the validity
-of Timed Text Markup Language content as defined by this specification.
-In particular, the formal validity of TTML Content
-is defined by <a href="#conformance-content"><b>3.1 Document Conformance</b></a>.</p></div></div><div class="div1">
-<h2><a id="media-types-registration"></a>D Media Type Registration</h2><p><em>This appendix is normative.</em></p><div class="issue"><p class="prefix"><a id="issue-352"></a><b>Issue (issue-352):</b></p><p class="prefix"><b>Restore Media Type Registration</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/352">http://www.w3.org/AudioVideo/TT/tracker/issues/352</a></p><p>Restore and update media type registration for IANA update.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p></p><div class="issue"><p class="prefix"><a id="issue-351"></a><b>Issue (issue-351):</b></p><p class="prefix"><b>Processor Profiles Parameter</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/351">http://www.w3.org/AudioVideo/TT/tracker/issues/351</a></p><p>Add definition of <code>processorProfiles</code> media type parameter.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div></div><div class="div1">
-<h2><a id="features"></a>E Features</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies (1) a set of feature designations, each of which
-labels one or more syntactic and/or semantic features defined by this
-specification, and (2) for each designated feature, whether the feature is mandatory
-or optional for a transformation or <a href="#terms-presentation-processor">presentation processor</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A TTML processor is said to <em>implement the transformation semantics</em> or
-<em>implement the presentation semantics</em> of feature designation <em>F</em>
-if it satisfies the requirements of this appendix with respect to the definition of
-feature designation <em>F</em> as pertains to transformation or
-presentation processing, respectively.</p></div><div class="div2">
-<h3><a id="feature-designations"></a>E.1 Feature Designations</h3><p>A feature designation is expressed as a string that adheres to the following
-form:</p><div class="exampleInner"><pre>
-feature-designation
-  : feature-namespace designation
-
-feature-namespace
-  : <em>TT Feature Namespace</em>                    // http://www.w3.org/ns/ttml/feature/
-
-designation
-  : "#" token-char+
-
-token-char
-  : { XML NameChar }                        // XML 1.1 Production [4a]
-</pre></div><p>All values of <code>feature-designation</code> not defined by this specification are reserved
-for future standardization.</p><p>The following sub-sections define all feature designations, expressed
-as relative URIs (fragment identifiers) with respect to the 
-TT Feature Namespace base URI.</p><table border="1" class="ednote" summary="Editorial note: #animation subset features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: #animation subset features</b></td><td align="right" valign="top">2013-08-26</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add fine grained subset features of #animation.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: #inline-region features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: #inline-region features</b></td><td align="right" valign="top">2014-03-27</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add feature(s) associated with support for explicit and implied inline regions.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: New style property features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: New style property features</b></td><td align="right" valign="top">2014-10-02</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add features to cover new style properties: border, fontVariantPosition, ruby, rubyAlign, rubyOffset, rubyPosition, textOrientation, etc.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: New embedded content features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: New embedded content features</b></td><td align="right" valign="top">2014-11-27</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add features to cover new embedded content features: audio, data, font, image, etc.</td></tr></table><div class="div3">
-<h4><a id="feature-animation"></a>E.1.1 #animation</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#animation</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#animation"><b>13 Animation</b></a>:</p><ul><li><p><a href="#animation-vocabulary-animation"><code>animation</code></a></p></li><li><p><a href="#animation-vocabulary-animate"><code>animate</code></a></p></li><li><p><a href="#animation-vocabulary-set"><code>set</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#animation</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a id="feature-backgroundColor"></a>E.1.2 #backgroundColor</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#backgroundColor</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#backgroundColor</code> feature if it (1) implements presentation semantic support
-for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a id="feature-backgroundColor-block"></a>E.1.3 #backgroundColor-block</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#backgroundColor-block</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that would generate a
-block area during presentation processing.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#backgroundColor-block</code> feature if it (1) implements presentation semantic
-support for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that generates a
-block area
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a id="feature-backgroundColor-inline"></a>E.1.4 #backgroundColor-inline</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#backgroundColor-inline</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that would generate an
-inline area during presentation processing.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#backgroundColor-inline</code> feature if it (1) implements presentation semantic
-support for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that generates an
-inline area
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a id="feature-backgroundColor-region"></a>E.1.5 #backgroundColor-region</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#backgroundColor-region</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#backgroundColor-region</code> feature if it (1) implements presentation semantic
-support for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space
-.</p></div><div class="div3">
-<h4><a id="feature-bidi"></a>E.1.6 #bidi</h4><p>A TTML processor supports the <code>#bidi</code> feature if it
-supports the following features:</p><ul><li><p><a href="#feature-direction"><code>#direction</code></a></p></li><li><p><a href="#feature-unicodeBidi"><code>#unicodeBidi</code></a></p></li><li><p><a href="#feature-writingMode-horizontal"><code>#writingMode-horizontal</code></a></p></li></ul></div><div class="div3">
-<h4><a id="feature-border"></a>E.1.7 #border</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#border</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-border"><code>tts:border</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#border</code> feature if it (1) implements presentation semantic support
-for the <a href="#style-attribute-border"><code>tts:border</code></a>
-attribute
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of border colors,
-including all primary and secondary colors of the SRGB color space.</p><table border="1" class="ednote" summary="Editorial note: Features related to tts:border"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Features related to tts:border</b></td><td align="right" valign="top">2013-08-23</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add additional border related features.</td></tr></table></div><div class="div3">
-<h4><a id="feature-cellResolution"></a>E.1.8 #cellResolution</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#cellResolution</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-cellResolution"><code>ttp:cellResolution</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#cellResolution</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-cellResolution"><code>ttp:cellResolution</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-clockMode"></a>E.1.9 #clockMode</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#clockMode</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#clockMode</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-clockMode-gps"></a>E.1.10 #clockMode-gps</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#clockMode-gps</code> feature if it recognizes and is capable of
-transforming the <code>gps</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#clockMode-gps</code> feature if it implements presentation semantic support
-for the <code>gps</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-clockMode-local"></a>E.1.11 #clockMode-local</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#clockMode-local</code> feature if it recognizes and is capable of
-transforming the <code>local</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#clockMode-local</code> feature if it implements presentation semantic support
-for the <code>local</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-clockMode-utc"></a>E.1.12 #clockMode-utc</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#clockMode-utc</code> feature if it recognizes and is capable of
-transforming the <code>utc</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#clockMode-utc</code> feature if it implements presentation semantic support
-for the <code>utc</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-color"></a>E.1.13 #color</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#color</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-color"><code>tts:color</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#color</code> feature if it (1) implements presentation semantic support
-for the <a href="#style-attribute-color"><code>tts:color</code></a>
-attribute
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a id="feature-content"></a>E.1.14 #content</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#content</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#content"><b>8 Content</b></a>:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li><li><p><a href="#content-vocabulary-br"><code>br</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#content</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a id="feature-core"></a>E.1.15 #core</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#core</code>
-feature if it recognizes and is capable of transforming the following
-core attributes vocabulary defined by <a href="#content"><b>8 Content</b></a>:</p><ul><li><p><a href="#content-attribute-xml-id">@<code>xml:id</code></a></p></li><li><p><a href="#content-attribute-xml-id">@<code>xml:lang</code></a></p></li><li><p><a href="#content-attribute-xml-id">@<code>xml:space</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#core</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a id="feature-direction"></a>E.1.16 #direction</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#direction</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-direction"><code>tts:direction</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#direction</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-direction"><code>tts:direction</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-display"></a>E.1.17 #display</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#display</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#display</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-display-block"></a>E.1.18 #display-block</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#display-block</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that would generate a
-block area during presentation processing.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#display-block</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that generates a
-block area.</p></div><div class="div3">
-<h4><a id="feature-display-inline"></a>E.1.19 #display-inline</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#display-inline</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that would generate an
-inline area during presentation processing.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#display-inline</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that generates an
-inline area.</p></div><div class="div3">
-<h4><a id="feature-display-region"></a>E.1.20 #display-region</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#display-region</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#display-region</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></div><div class="div3">
-<h4><a id="feature-displayAlign"></a>E.1.21 #displayAlign</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#displayAlign</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-displayAlign"><code>tts:displayAlign</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#displayAlign</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-displayAlign"><code>tts:displayAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-dropMode"></a>E.1.22 #dropMode</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#dropMode</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#dropMode</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-dropMode-dropNTSC"></a>E.1.23 #dropMode-dropNTSC</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#dropMode-dropNTSC</code> feature if it recognizes and is capable of
-transforming the <code>dropNTSC</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#dropMode-dropNTSC</code> feature if it implements presentation semantic support
-for the <code>dropNTSC</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-dropMode-dropPAL"></a>E.1.24 #dropMode-dropPAL</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#dropMode-dropPAL</code> feature if it recognizes and is capable of
-transforming the <code>dropPAL</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#dropMode-dropPAL</code> feature if it implements presentation semantic support
-for the <code>dropPAL</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-dropMode-nonDrop"></a>E.1.25 #dropMode-nonDrop</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#dropMode-nonDrop</code> feature if it recognizes and is capable of
-transforming the <code>nonDrop</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#dropMode-nonDrop</code> feature if it implements presentation semantic support
-for the <code>nonDrop</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-extent"></a>E.1.26 #extent</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#extent</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#extent</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-extent-region"></a>E.1.27 #extent-region</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#extent-region</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#extent-region</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></div><div class="div3">
-<h4><a id="feature-extent-root"></a>E.1.28 #extent-root</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#extent-root</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#extent-root</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to a <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element.</p></div><div class="div3">
-<h4><a id="feature-fontFamily"></a>E.1.29 #fontFamily</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontFamily</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontFamily</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontFamily-generic"></a>E.1.30 #fontFamily-generic</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontFamily-generic</code> feature if it recognizes and is
-capable of transforming <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontFamily-generic</code> feature if it implements presentation semantic
-support for <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontFamily-non-generic"></a>E.1.31 #fontFamily-non-generic</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontFamily-non-generic</code> feature if it recognizes and is
-capable of transforming <a href="#style-value-familyName">&lt;familyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontFamily-non-generic</code> feature if it implements presentation semantic
-support for <a href="#style-value-familyName">&lt;familyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontSize"></a>E.1.32 #fontSize</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontSize</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontSize</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontSize-anamorphic"></a>E.1.33 #fontSize-anamorphic</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontSize-anamorphic</code> feature if it recognizes and is
-capable of transforming values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of two <a href="#style-value-length">&lt;length&gt;</a> specifications.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontSize-anamorphic</code> feature if it implements presentation semantic
-support for defined values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of two <a href="#style-value-length">&lt;length&gt;</a> specifications.</p></div><div class="div3">
-<h4><a id="feature-fontSize-isomorphic"></a>E.1.34 #fontSize-isomorphic</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontSize-isomorphic</code> feature if it recognizes and is
-capable of transforming values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of a single <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontSize-isomorphic</code> feature if it implements presentation semantic
-support for defined values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of a single <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a id="feature-fontStyle"></a>E.1.35 #fontStyle</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontStyle</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontStyle</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontStyle-italic"></a>E.1.36 #fontStyle-italic</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontStyle-italic</code> feature if it recognizes and is
-capable of transforming the <code>italic</code> value of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontStyle-italic</code> feature if it implements presentation semantic
-support for the <code>italic</code> of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontStyle-oblique"></a>E.1.37 #fontStyle-oblique</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontStyle-oblique</code> feature if it recognizes and is
-capable of transforming the <code>oblique</code> value of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontStyle-oblique</code> feature if it implements presentation semantic
-support for the <code>oblique</code> of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontWeight"></a>E.1.38 #fontWeight</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontWeight</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontWeight</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-fontWeight-bold"></a>E.1.39 #fontWeight-bold</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#fontWeight-bold</code> feature if it recognizes and is
-capable of transforming <code>bold</code> value of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#fontWeight-bold</code> feature if it implements presentation semantic
-support for the <code>bold</code> of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-frameRate"></a>E.1.40 #frameRate</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#frameRate</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-frameRate"><code>ttp:frameRate</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#frameRate</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-frameRate"><code>ttp:frameRate</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-frameRateMultiplier"></a>E.1.41 #frameRateMultiplier</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#frameRateMultiplier</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-frameRateMultiplier"><code>ttp:frameRateMultiplier</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#frameRateMultiplier</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-frameRateMultiplier"><code>ttp:frameRateMultiplier</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-layout"></a>E.1.42 #layout</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#layout</code>
-feature if it (1) recognizes and is capable of transforming the following
-vocabulary defined by <a href="#layout"><b>11 Layout</b></a>:</p><ul><li><p><a href="#layout-vocabulary-layout"><code>layout</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#layout-attribute-region">@<code>region</code></a></p></li></ul><p>and (2) supports the following attributes when applied to the
-<a href="#layout-vocabulary-region"><code>region</code></a> element:</p><ul><li><p><a href="#style-attribute-extent"><code>tts:extent</code></a></p></li><li><p><a href="#style-attribute-origin"><code>tts:origin</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#layout</code>
-feature if it implements presentation semantic support for the
-same vocabulary and features enumerated above.</p></div><div class="div3">
-<h4><a id="feature-length"></a>E.1.43 #length</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#length</code>
-feature if it recognizes and is capable of transforming all defined
-values of the <a href="#style-value-length">&lt;length&gt;</a>
-style value expression.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#length</code>
-feature if it implements presentation semantic support for all defined values of
-the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length</code> is intended to imply support for the following features:
-<code>#length-integer</code>,
-<code>#length-real</code>,
-<code>#length-positive</code>,
-<code>#length-negative</code>,
-<code>#length-cell</code>,
-<code>#length-em</code>,
-<code>#length-percentage</code>, and
-<code>#length-pixel</code>.</p></div></div><div class="div3">
-<h4><a id="feature-length-cell"></a>E.1.44 #length-cell</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-cell</code> feature if it recognizes and is capable of
-transforming scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>c</code> (cell) units.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-cell</code> feature if it implements presentation semantic support
-for scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>c</code> (cell) units.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-cell</code> does not, by itself, imply support for
-<code>#length-integer</code>,
-<code>#length-real</code>,
-<code>#length-positive</code>, or
-<code>#length-negative</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-em"></a>E.1.45 #length-em</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-em</code> feature if it recognizes and is capable of
-transforming scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>em</code> (EM) units.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-em</code> feature if it implements presentation semantic support
-for scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>em</code> (EM) units.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-em</code> does not, by itself, imply support for
-<code>#length-integer</code>,
-<code>#length-real</code>,
-<code>#length-positive</code>, or
-<code>#length-negative</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-integer"></a>E.1.46 #length-integer</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-integer</code> feature if it recognizes and is
-capable of transforming integer values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-integer</code> feature if it implements presentation semantic
-support for integer values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-integer</code> does not, by itself, imply support for
-<code>#length-positive</code> or
-<code>#length-negative</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-negative"></a>E.1.47 #length-negative</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-negative</code> feature if it recognizes and is
-capable of transforming negative values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-negative</code> feature if it implements presentation semantic
-support for negative values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-negative</code> does not, by itself, imply support for
-<code>#length-integer</code> or
-<code>#length-real</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-percentage"></a>E.1.48 #length-percentage</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-percentage</code> feature if it recognizes and is
-capable of transforming percentage values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-percentage</code> feature if it implements presentation semantic
-support for percentage values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-percentage</code> does not, by itself, imply support for
-<code>#length-integer</code>,
-<code>#length-real</code>,
-<code>#length-positive</code>, or
-<code>#length-negative</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-pixel"></a>E.1.49 #length-pixel</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-pixel</code> feature if it recognizes and is capable of
-transforming scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>px</code> (pixel) units.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-pixel</code> feature if it implements presentation semantic support
-for scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>px</code> (pixel) units.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-pixel</code> does not, by itself, imply support for
-<code>#length-integer</code>,
-<code>#length-real</code>,
-<code>#length-positive</code>, or
-<code>#length-negative</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-positive"></a>E.1.50 #length-positive</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-positive</code> feature if it recognizes and is
-capable of transforming positive values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-positive</code> feature if it implements presentation semantic
-support for positive values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-positive</code> is intended to imply support for zero valued
-<a href="#style-value-length">&lt;length&gt;</a> style value
-expressions.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-positive</code> does not, by itself, imply support for
-<code>#length-integer</code> or
-<code>#length-real</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-length-real"></a>E.1.51 #length-real</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#length-real</code> feature if it recognizes and is
-capable of transforming real values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#length-real</code> feature if it implements presentation semantic
-support for real values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-real</code> is intended to imply support for
-integer valued <a href="#style-value-length">&lt;length&gt;</a> style value
-expressions as well as real valued expressions.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>Support for <code>#length-real</code> does not, by itself, imply support for
-<code>#length-positive</code> or
-<code>#length-negative</code> features.</p></div></div><div class="div3">
-<h4><a id="feature-lineBreak-uax14"></a>E.1.52 #lineBreak-uax14</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#lineBreak-uax14</code> feature if it recognizes and is capable of
-transforming requirements expressed by <a href="#uax14">[UAX14]</a> into its
-target document space.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#lineBreak-uax14</code> feature if it implements presentation semantic support
-for <a href="#uax14">[UAX14]</a> as applies to line breaking.</p></div><div class="div3">
-<h4><a id="feature-lineHeight"></a>E.1.53 #lineHeight</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#lineHeight</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-lineHeight"><code>tts:lineHeight</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#lineHeight</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-lineHeight"><code>tts:lineHeight</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-markerMode"></a>E.1.54 #markerMode</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#markerMode</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#markerMode</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-markerMode-continuous"></a>E.1.55 #markerMode-continuous</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#markerMode-continuous</code> feature if it recognizes and is capable of
-transforming the <code>continuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#markerMode-continuous</code> feature if it implements presentation semantic support
-for the <code>continuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-markerMode-discontinuous"></a>E.1.56 #markerMode-discontinuous</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#markerMode-discontinuous</code> feature if it recognizes and is capable of
-transforming the <code>discontinuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#markerMode-discontinuous</code> feature if it implements presentation semantic support
-for the <code>discontinuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-metadata"></a>E.1.57 #metadata</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#metadata</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#metadata"><b>14 Metadata</b></a>:</p><ul><li><p><a href="#metadata-vocabulary-metadata"><code>metadata</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:title</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:desc</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:copyright</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:agent</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:name</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:actor</code></a></p></li><li><p><a href="#metadata-attribute-agent">@<code>ttm:agent</code></a></p></li><li><p><a href="#metadata-attribute-role">@<code>ttm:role</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#metadata</code>
-feature if it recognizes and is capable of presenting the information
-expressed by the same vocabulary enumerated above.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not define a standardized form for the
-presentation of metadata information. The presentation or ability to
-present metadata information is considered to be implementation
-dependent.</p></div></div><div class="div3">
-<h4><a id="feature-nested-div"></a>E.1.58 #nested-div</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#nested-div</code>
-feature if it recognizes and is capable of transforming nested
-<a href="#content-vocabulary-div"><code>div</code></a> elements.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#nested-div</code>
-feature if it implements presentation semantic support for nested
-<a href="#content-vocabulary-div"><code>div</code></a> elements.</p></div><div class="div3">
-<h4><a id="feature-nested-span"></a>E.1.59 #nested-span</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#nested-span</code>
-feature if it recognizes and is capable of transforming nested
-<a href="#content-vocabulary-span"><code>span</code></a> elements.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#nested-span</code>
-feature if it implements presentation semantic support for nested
-<a href="#content-vocabulary-span"><code>span</code></a> elements.</p></div><div class="div3">
-<h4><a id="feature-opacity"></a>E.1.60 #opacity</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#opacity</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-opacity"><code>tts:opacity</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#opacity</code> feature if it (1) implements presentation semantic support for
-the <a href="#style-attribute-opacity"><code>tts:opacity</code></a>
-attribute and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least eight (8) values of opacity.</p></div><div class="div3">
-<h4><a id="feature-origin"></a>E.1.61 #origin</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#origin</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-origin"><code>tts:origin</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#origin</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-origin"><code>tts:origin</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-overflow"></a>E.1.62 #overflow</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#overflow</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#overflow</code> feature if it implements presentation semantic support for
-all defined values of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-overflow-visible"></a>E.1.63 #overflow-visible</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#overflow-visible</code> feature if it recognizes and is capable of
-transforming the <code>visible</code> value of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#overflow-visible</code> feature if it implements presentation semantic support for
-the <code>visible</code> value of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-padding"></a>E.1.64 #padding</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#padding</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-padding"><code>tts:padding</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#padding</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-padding"><code>tts:padding</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-padding-1"></a>E.1.65 #padding-1</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#padding-1</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of one <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#padding-1</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of one <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a id="feature-padding-2"></a>E.1.66 #padding-2</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#padding-2</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of two <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#padding-2</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of two <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a id="feature-padding-3"></a>E.1.67 #padding-3</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#padding-3</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of three <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#padding-3</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of three <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a id="feature-padding-4"></a>E.1.68 #padding-4</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#padding-4</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of four <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#padding-4</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of four <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a id="feature-pixelAspectRatio"></a>E.1.69 #pixelAspectRatio</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#pixelAspectRatio</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-pixelAspectRatio"><code>ttp:pixelAspectRatio</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#pixelAspectRatio</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-pixelAspectRatio"><code>ttp:pixelAspectRatio</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-presentation"></a>E.1.70 #presentation</h4><p>A TTML processor supports the
-<code>#presentation</code> feature if it
-(1) satisfies the generic processor criteria defined by 
-<a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a>,
-(2) implements support for the region and line layout
-semantics defined by <a href="#semantics-region-layout"><b>11.3.1 Region Layout and Presentation</b></a> and
-<a href="#semantics-line-layout"><b>11.3.2 Line Layout</b></a>, respectively, and
-(3) implements presentation semantics for the following features:</p><ul><li><p><a href="#content"><code>#content</code></a></p></li><li><p><a href="#feature-core"><code>#core</code></a></p></li><li><p><a href="#feature-profile"><code>#profile</code></a></p></li><li><p><a href="#feature-structure"><code>#structure</code></a></p></li><li><p><a href="#feature-time-offset"><code>#time-offset</code></a></p></li><li><p><a href="#timing"><code>#timing</code></a></p></li></ul><p>
-In addition, a TTML processor that supports the
-<code>#presentation</code> feature should satisfy the user agent
-accessibility guidelines specified by <a href="#uaag">[UAAG]</a>.</p></div><div class="div3">
-<h4><a id="feature-profile"></a>E.1.71 #profile</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#profile</code>
-feature if it recognizes and is capable of transforming the
-<a href="#profile-attribute-profile"><code>ttp:profile</code></a>
-attribute on the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element and
-transforming the following vocabulary defined by
-<a href="#parameter-element-vocabulary"><b>7.1 Parameter Element Vocabulary</b></a>:</p><ul><li><p><a href="#profile-vocabulary-profile"><code>ttp:profile</code></a></p></li><li><p><a href="#profile-vocabulary-features"><code>ttp:features</code></a></p></li><li><p><a href="#profile-vocabulary-feature"><code>ttp:feature</code></a></p></li><li><p><a href="#profile-vocabulary-extensions"><code>ttp:extensions</code></a></p></li><li><p><a href="#profile-vocabulary-extension"><code>ttp:extension</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#profile</code> feature if it implements presentation semantic support
-for the same vocabulary specified above.</p></div><div class="div3">
-<h4><a id="feature-showBackground"></a>E.1.72 #showBackground</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#showBackground</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-showBackground"><code>tts:showBackground</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#showBackground</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-showBackground"><code>tts:showBackground</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-structure"></a>E.1.73 #structure</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#structure</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#content"><b>8 Content</b></a>:</p><ul><li><p><a href="#document-structure-vocabulary-tt"><code>tt</code></a></p></li><li><p><a href="#document-structure-vocabulary-head"><code>head</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#structure</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a id="feature-styling"></a>E.1.74 #styling</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#styling</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#styling"><b>10 Styling</b></a>:</p><ul><li><p><a href="#styling-vocabulary-styling"><code>styling</code></a></p></li><li><p><a href="#styling-vocabulary-style"><code>style</code></a></p></li><li><p><a href="#style-attribute-style">@<code>style</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#styling</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a id="feature-styling-chained"></a>E.1.75 #styling-chained</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#styling-chained</code> feature if it recognizes and is capable
-of transforming chained style association as defined by <a href="#semantics-style-association-chained-referential"><b>10.4.1.3 Chained Referential Styling</b></a>.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#styling-chained</code> feature if it implements presentation semantic
-support for chained style association as defined by <a href="#semantics-style-association-chained-referential"><b>10.4.1.3 Chained Referential Styling</b></a>.</p></div><div class="div3">
-<h4><a id="feature-styling-inheritance-content"></a>E.1.76 #styling-inheritance-content</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#styling-inheritance</code> feature if it recognizes and is
-capable of transforming content style inheritance as defined by
-<a href="#semantics-style-inheritance-content"><b>10.4.2.1 Content Style Inheritance</b></a>.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#styling-inheritance-content</code> feature if it implements
-presentation semantic support for content style inheritance as defined by <a href="#semantics-style-inheritance-content"><b>10.4.2.1 Content Style Inheritance</b></a>.</p></div><div class="div3">
-<h4><a id="feature-styling-inheritance-region"></a>E.1.77 #styling-inheritance-region</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#styling-inheritance</code> feature if it recognizes and is
-capable of transforming region style inheritance as defined by
-<a href="#semantics-style-inheritance-region"><b>10.4.2.2 Region Style Inheritance</b></a>.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#styling-inheritance-region</code> feature if it implements
-presentation semantic support for region style inheritance as defined by <a href="#semantics-style-inheritance-region"><b>10.4.2.2 Region Style Inheritance</b></a>.</p></div><div class="div3">
-<h4><a id="feature-styling-inline"></a>E.1.78 #styling-inline</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#styling-inline</code> feature if it recognizes and is capable
-of transforming inline style association as defined by <a href="#semantics-style-association-inline"><b>10.4.1.1 Inline Styling</b></a>.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#styling-inline</code> feature if it implements presentation semantic support
-for inline style association as defined by <a href="#semantics-style-association-inline"><b>10.4.1.1 Inline Styling</b></a>.</p></div><div class="div3">
-<h4><a id="feature-styling-nested"></a>E.1.79 #styling-nested</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#styling-nested</code> feature if it recognizes and is capable
-of transforming nested style association as defined by <a href="#semantics-style-association-nested"><b>10.4.1.4 Nested Styling</b></a>.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#styling-nested</code> feature if it implements presentation semantic support
-for nested style association as defined by <a href="#semantics-style-association-nested"><b>10.4.1.4 Nested Styling</b></a>.</p></div><div class="div3">
-<h4><a id="feature-styling-referential"></a>E.1.80 #styling-referential</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#styling-referential</code> feature if it recognizes and is capable
-of transforming referential style association as defined by <a href="#semantics-style-association-referential"><b>10.4.1.2 Referential Styling</b></a>.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#styling-referential</code> feature if it implements presentation semantic
-support for referential style association as defined by <a href="#semantics-style-association-referential"><b>10.4.1.2 Referential Styling</b></a>.</p></div><div class="div3">
-<h4><a id="feature-subFrameRate"></a>E.1.81 #subFrameRate</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#subFrameRate</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-subFrameRate"><code>ttp:subFrameRate</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#subFrameRate</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-subFrameRate"><code>ttp:subFrameRate</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textAlign"></a>E.1.82 #textAlign</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textAlign</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textAlign</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textAlign-absolute"></a>E.1.83 #textAlign-absolute</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textAlign-absolute</code> feature if it recognizes and is
-capable of transforming the <code>left</code>, <code>center</code>,
-and <code>right</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textAlign-absolute</code> feature if it implements presentation semantic
-support for the <code>left</code>, <code>center</code>, and
-<code>right</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textAlign-relative"></a>E.1.84 #textAlign-relative</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textAlign-relative</code> feature if it recognizes and is
-capable of transforming the <code>start</code>, <code>center</code>,
-and <code>end</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textAlign-relative</code> feature if it implements presentation semantic
-support for the <code>start</code>, <code>center</code>, and
-<code>end</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textDecoration"></a>E.1.85 #textDecoration</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textDecoration</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textDecoration</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textDecoration-over"></a>E.1.86 #textDecoration-over</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textDecoration-over</code> feature if it recognizes and is
-capable of transforming the <code>overline</code> and
-<code>noOverline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textDecoration-over</code> feature if it implements
-presentation semantic support for the <code>overline</code> and
-<code>noOverline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textDecoration-through"></a>E.1.87 #textDecoration-through</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textDecoration-through</code> feature if it recognizes and is
-capable of transforming the <code>lineThrough</code> and
-<code>noLineThrough</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textDecoration-through</code> feature if it implements
-presentation semantic support for the <code>lineThrough</code> and
-<code>noLineThrough</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textDecoration-under"></a>E.1.88 #textDecoration-under</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textDecoration-under</code> feature if it recognizes and is
-capable of transforming the <code>underline</code> and
-<code>noUnderline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textDecoration-under</code> feature if it implements
-presentation semantic support for the <code>underline</code> and
-<code>noUnderline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textOrientation"></a>E.1.89 #textOrientation</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textOrientation</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-textOrientation"><code>tts:textOrientation</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textOrientation</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-textOrientation"><code>tts:textOrientation</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textOutline"></a>E.1.90 #textOutline</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textOutline</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textOutline</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-textOutline-blurred"></a>E.1.91 #textOutline-blurred</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textOutline-blurred</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that includes a blur radius specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textOutline-blurred</code> feature if it implements presentation semantic support
-for values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that includes a blur radius specification.</p></div><div class="div3">
-<h4><a id="feature-textOutline-unblurred"></a>E.1.92 #textOutline-unblurred</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#textOutline-unblurred</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that does not include a blur radius specification.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#textOutline-unblurred</code> feature if it implements presentation semantic support
-for values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that does not include a blur radius specification.</p></div><div class="div3">
-<h4><a id="feature-tickRate"></a>E.1.93 #tickRate</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#tickRate</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-tickRate"><code>ttp:tickRate</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#tickRate</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-tickRate"><code>ttp:tickRate</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-timeBase-clock"></a>E.1.94 #timeBase-clock</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#timeBase-clock</code> feature if it recognizes and is capable
-of transforming the <code>clock</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-clockMode"><code>#clockMode</code></a> feature.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#timeBase-clock</code> feature if it implements presentation
-semantic support for the <code>clock</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-clockMode"><code>#clockMode</code></a> feature.</p></div><div class="div3">
-<h4><a id="feature-timeBase-media"></a>E.1.95 #timeBase-media</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#timeBase-media</code> feature if it recognizes and is capable
-of transforming the <code>media</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#timeBase-media</code> feature if it implements presentation
-semantic support for the <code>media</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-timeBase-smpte"></a>E.1.96 #timeBase-smpte</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#timeBase-smpte</code> feature if it recognizes and is capable
-of transforming the <code>smpte</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-dropMode"><code>#dropMode</code></a> feature.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#timeBase-smpte</code> feature if it implements presentation
-semantic support for the <code>smpte</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-dropMode"><code>#dropMode</code></a> feature.</p></div><div class="div3">
-<h4><a id="feature-timeContainer"></a>E.1.97 #timeContainer</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#timeContainer</code> feature if it recognizes and is capable of
-transforming the <a href="#timing-attribute-timeContainer"><code>timeContainer</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#timeContainer</code> feature if it implements presentation semantic support
-for the <a href="#timing-attribute-timeContainer"><code>timeContainer</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-time-clock"></a>E.1.98 #time-clock</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#time-clock</code> feature if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : hours ":" minutes ":" seconds ( fraction )?
-</pre></div><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#time-clock</code> feature if it implements presentation
-semantic support for the same syntax specified above.</p></div><div class="div3">
-<h4><a id="feature-time-clock-with-frames"></a>E.1.99 #time-clock-with-frames</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#time-clock-with-frames</code> feature if it supports the
-<a href="#feature-frameRate"><code>#frameRate</code></a>,
-<a href="#feature-frameRateMultiplier"><code>#frameRateMultiplier</code></a>, and
-<a href="#feature-subFrameRate"><code>#subFrameRate</code></a> features
-and if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : hours ":" minutes ":" seconds ( fraction | ":" frames ( "." sub-frames )? )?
-</pre></div><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#time-clock-with-frames</code> feature if it implements
-presentation semantic support for the same features and syntax
-specified above.</p></div><div class="div3">
-<h4><a id="feature-time-offset"></a>E.1.100 #time-offset</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#time-offset</code> feature if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : time-count fraction? ( "h" | "m" | "s" | "ms" )
-</pre></div><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#time-offset</code> feature if it implements presentation
-semantic support for the same syntax specified above.</p></div><div class="div3">
-<h4><a id="feature-time-offset-with-frames"></a>E.1.101 #time-offset-with-frames</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#time-offset-with-frames</code> feature if it supports the
-<a href="#feature-frameRate"><code>#frameRate</code></a>,
-<a href="#feature-frameRateMultiplier"><code>#frameRateMultiplier</code></a>, and
-<a href="#feature-subFrameRate"><code>#subFrameRate</code></a> features
-and if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : time-count fraction? "f"
-</pre></div><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#time-offset-with-frames</code> feature if it implements
-presentation semantic support for the same features and syntax
-specified above.</p></div><div class="div3">
-<h4><a id="feature-time-offset-with-ticks"></a>E.1.102 #time-offset-with-ticks</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#time-offset-with-ticks</code> feature if it supports the 
-<a href="#feature-tickRate"><code>#tickRate</code></a> feature
-and if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : time-count fraction? "t"
-</pre></div><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#time-offset-with-ticks</code> feature if it implements presentation
-semantic support for the same features and syntax specified above.</p></div><div class="div3">
-<h4><a id="feature-timing"></a>E.1.103 #timing</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#timing</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#timing"><b>12 Timing</b></a>:</p><ul><li><p><a href="#timing-attribute-begin">@<code>begin</code></a></p></li><li><p><a href="#timing-attribute-dur">@<code>dur</code></a></p></li><li><p><a href="#timing-attribute-end">@<code>end</code></a></p></li></ul><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the <code>#timing</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a id="feature-transformation"></a>E.1.104 #transformation</h4><p>A TTML processor supports the
-<code>#transformation</code> feature if it
-(1) satisfies the generic processor criteria defined by 
-<a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a> and
-(2) implements the transformation semantics of the following features:</p><ul><li><p><a href="#content"><code>#content</code></a></p></li><li><p><a href="#feature-core"><code>#core</code></a></p></li><li><p><a href="#feature-profile"><code>#profile</code></a></p></li><li><p><a href="#feature-structure"><code>#structure</code></a></p></li><li><p><a href="#feature-time-offset"><code>#time-offset</code></a></p></li><li><p><a href="#timing"><code>#timing</code></a></p></li></ul></div><div class="div3">
-<h4><a id="feature-unicodeBidi"></a>E.1.105 #unicodeBidi</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#unicodeBidi</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-unicodeBidi"><code>tts:unicodeBidi</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#unicodeBidi</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-unicodeBidi"><code>tts:unicodeBidi</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-version"></a>E.1.106 #version</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#version</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-version"><code>ttp:version</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#version</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-version"><code>ttp:version</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-visibility"></a>E.1.107 #visibility</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#visibility</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#visibility</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-visibility-block"></a>E.1.108 #visibility-block</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#visibility-block</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that would generate a
-block area during presentation processing.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#visibility-block</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that generates a
-block area.</p></div><div class="div3">
-<h4><a id="feature-visibility-inline"></a>E.1.109 #visibility-inline</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#visibility-inline</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that would generate an
-inline area during presentation processing.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#visibility-inline</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that generates an
-inline area.</p></div><div class="div3">
-<h4><a id="feature-visibility-region"></a>E.1.110 #visibility-region</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#visibility-region</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#visibility-region</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></div><div class="div3">
-<h4><a id="feature-wrapOption"></a>E.1.111 #wrapOption</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#wrapOption</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-wrapOption"><code>tts:wrapOption</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#wrapOption</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-wrapOption"><code>tts:wrapOption</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-writingMode"></a>E.1.112 #writingMode</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#writingMode</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#writingMode</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-writingMode-vertical"></a>E.1.113 #writingMode-vertical</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#writingMode-vertical</code> feature if it recognizes and is
-capable of transforming the <code>tbrl</code>, <code>tblr</code>, and
-<code>tb</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#writingMode-vertical</code> feature if it implements presentation semantic
-support for the <code>tbrl</code>, <code>tblr</code>, and
-<code>tb</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-writingMode-horizontal"></a>E.1.114 #writingMode-horizontal</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#writingMode-horizontal</code> feature if it recognizes and is
-capable of transforming the <code>lrtb</code>, <code>rltb</code>,
-<code>lr</code> and <code>rl</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#writingMode-horizontal</code> feature if it implements presentation semantic
-support for the <code>lrtb</code>, <code>rltb</code>, <code>lr</code>
-and <code>rl</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-writingMode-horizontal-lr"></a>E.1.115 #writingMode-horizontal-lr</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#writingMode-horizontal</code> feature if it recognizes and is
-capable of transforming the <code>lrtb</code> and <code>lr</code>
-values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#writingMode-horizontal-lr</code> feature if it implements presentation semantic
-support for the <code>lrtb</code> and <code>lr</code> values of the
-<a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-writingMode-horizontal-rl"></a>E.1.116 #writingMode-horizontal-rl</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#writingMode-horizontal</code> feature if it recognizes and is
-capable of transforming the <code>rltb</code> and <code>rl</code>
-values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#writingMode-horizontal-rl</code> feature if it implements presentation semantic
-support for the <code>rltb</code> and <code>rl</code> values of the
-<a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a id="feature-zIndex"></a>E.1.117 #zIndex</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#zIndex</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-zIndex"><code>tts:zIndex</code></a>
-attribute.</p><p>A TTML <a href="#terms-presentation-processor">presentation processor</a> supports the
-<code>#zIndex</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-zIndex"><code>tts:zIndex</code></a>
-attribute.</p></div></div><div class="div2">
-<h3><a id="feature-support"></a>E.2 Feature Support</h3><p>The following table, <a href="#feature-support-table"><b>Table E-1 – Feature Support</b></a>,
-enumerates every defined feature designation (expressed without the TT
-Feature Namespace), and, for each designated feature, specifies
-whether the feature must be implemented, i.e., is mandatory (M), or may be implemented, i.e.,
-is optional (O), for transformation and <a href="#terms-presentation-processor">presentation processor</a>s.</p><a id="feature-support-table"></a><table class="common"><caption>Table E-1 – Feature Support</caption><col width="60%" span="1"><col width="20%" span="1"><col width="20%" span="1"><tbody><tr><td><span class="strong">Feature</span></td><td><span class="strong">Transformation</span></td><td><span class="strong">Presentation</span></td></tr><tr><td><a href="#feature-animation"><code>#animation</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor"><code>#backgroundColor</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor-block"><code>#backgroundColor-block</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor-inline"><code>#backgroundColor-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor-region"><code>#backgroundColor-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-bidi"><code>#bidi</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-border"><code>#border</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-cellResolution"><code>#cellResolution</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode"><code>#clockMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode-gps"><code>#clockMode-gps</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode-local"><code>#clockMode-local</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode-utc"><code>#clockMode-utc</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-color"><code>#color</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-content"><code>#content</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-core"><code>#core</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-direction"><code>#direction</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display"><code>#display</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display-block"><code>#display-block</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display-inline"><code>#display-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display-region"><code>#display-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-displayAlign"><code>#displayAlign</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode"><code>#dropMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode-dropNTSC"><code>#dropMode-dropNTSC</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode-dropPAL"><code>#dropMode-dropPAL</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode-nonDrop"><code>#dropMode-nonDrop</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-extent"><code>#extent</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-extent-region"><code>#extent-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-extent-root"><code>#extent-root</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontFamily"><code>#fontFamily</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontFamily-generic"><code>#fontFamily-generic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontFamily-non-generic"><code>#fontFamily-non-generic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontSize"><code>#fontSize</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontSize-anamorphic"><code>#fontSize-anamorphic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontSize-isomorphic"><code>#fontSize-isomorphic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontStyle"><code>#fontStyle</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontStyle-italic"><code>#fontStyle-italic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontStyle-oblique"><code>#fontStyle-oblique</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontWeight"><code>#fontWeight</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontWeight-bold"><code>#fontWeight-bold</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-frameRate"><code>#frameRate</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-frameRateMultiplier"><code>#frameRateMultiplier</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-layout"><code>#layout</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length"><code>#length</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-cell"><code>#length-cell</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-em"><code>#length-em</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-integer"><code>#length-integer</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-negative"><code>#length-negative</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-percentage"><code>#length-percentage</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-pixel"><code>#length-pixel</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-positive"><code>#length-positive</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-real"><code>#length-real</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-lineBreak-uax14"><code>#lineBreak-uax14</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-lineHeight"><code>#lineHeight</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-markerMode"><code>#markerMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-markerMode-continuous"><code>#markerMode-continuous</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-markerMode-discontinuous"><code>#markerMode-discontinuous</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-metadata"><code>#metadata</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-nested-div"><code>#nested-div</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-nested-span"><code>#nested-span</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-opacity"><code>#opacity</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-origin"><code>#origin</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-overflow"><code>#overflow</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-overflow-visible"><code>#overflow-visible</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding"><code>#padding</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-1"><code>#padding-1</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-2"><code>#padding-2</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-3"><code>#padding-3</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-4"><code>#padding-4</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-pixelAspectRatio"><code>#pixelAspectRatio</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-presentation"><code>#presentation</code></a></td><td>O</td><td>M</td></tr><tr><td><a href="#feature-profile"><code>#profile</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-showBackground"><code>#showBackground</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-structure"><code>#structure</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-styling"><code>#styling</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-chained"><code>#styling-chained</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-inheritance-content"><code>#styling-inheritance-content</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-inheritance-region"><code>#styling-inheritance-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-inline"><code>#styling-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-nested"><code>#styling-nested</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-referential"><code>#styling-referential</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-subFrameRate"><code>#subFrameRate</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textAlign"><code>#textAlign</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textAlign-absolute"><code>#textAlign-absolute</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textAlign-relative"><code>#textAlign-relative</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration"><code>#textDecoration</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration-over"><code>#textDecoration-over</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration-through"><code>#textDecoration-through</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration-under"><code>#textDecoration-under</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOrientation"><code>#textOrientation</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOutline"><code>#textOutline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOutline-blurred"><code>#textOutline-blurred</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOutline-unblurred"><code>#textOutline-unblurred</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-tickRate"><code>#tickRate</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeBase-clock"><code>#timeBase-clock</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeBase-media"><code>#timeBase-media</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeBase-smpte"><code>#timeBase-smpte</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeContainer"><code>#timeContainer</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-clock"><code>#time-clock</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-clock-with-frames"><code>#time-clock-with-frames</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-offset"><code>#time-offset</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-time-offset-with-frames"><code>#time-offset-with-frames</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-offset-with-ticks"><code>#time-offset-with-ticks</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timing"><code>#timing</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-transformation"><code>#transformation</code></a></td><td>M</td><td>O</td></tr><tr><td><a href="#feature-unicodeBidi"><code>#unicodeBidi</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-version"><code>#version</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility"><code>#visibility</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility-block"><code>#visibility-block</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility-inline"><code>#visibility-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility-region"><code>#visibility-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-wrapOption"><code>#wrapOption</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode"><code>#writingMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-vertical"><code>#writingMode-vertical</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-horizontal"><code>#writingMode-horizontal</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-horizontal-lr"><code>#writingMode-horizontal-lr</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-horizontal-rl"><code>#writingMode-horizontal-rl</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-zIndex"><code>#zIndex</code></a></td><td>O</td><td>O</td></tr></tbody></table><p>For the sake of convenience, the following table,
-<a href="#feature-transformation-mandatory-table"><b>Table E-2 – Mandatory Features - Transformation</b></a>, enumerates all
-mandatory features for a TTML <a href="#terms-transformation-processor">transformation processor</a>, providing additional
-comments to summarize the context of usage or the nature of the feature.
-The <a href="#terms-profile-definition-document">profile definition document</a> that defines the corresponding
-TTML Transformation Profile is specified in
-<a href="#profile-ttml2-transformation"><b>G.3 TTML2 Transformation Profile</b></a>.
-</p><a id="feature-transformation-mandatory-table"></a><table class="common"><caption>Table E-2 – Mandatory Features - Transformation</caption><col width="60%" span="1"><col width="40%" span="1"><tbody><tr><td><span class="strong">Feature</span></td><td><span class="strong">Comments</span></td></tr><tr><td><a href="#feature-content"><code>#content</code></a></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>,
-<a href="#content-vocabulary-br"><code>br</code></a>
-</td></tr><tr><td><a href="#feature-core"><code>#core</code></a></td><td>
-<a href="#content-attribute-xml-id">@<code>xml:id</code></a>,
-<a href="#content-attribute-xml-id">@<code>xml:lang</code></a>,
-<a href="#content-attribute-xml-id">@<code>xml:space</code></a>
-</td></tr><tr><td><a href="#feature-profile"><code>#profile</code></a></td><td></td></tr><tr><td><a href="#feature-structure"><code>#structure</code></a></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</code></a>,
-<a href="#document-structure-vocabulary-head"><code>head</code></a>
-</td></tr><tr><td><a href="#feature-time-offset"><code>#time-offset</code></a></td><td></td></tr><tr><td><a href="#feature-timing"><code>#timing</code></a></td><td>
-<a href="#timing-attribute-begin">@<code>begin</code></a>,
-<a href="#timing-attribute-dur">@<code>dur</code></a>,
-<a href="#timing-attribute-end">@<code>end</code></a>
-</td></tr><tr><td><a href="#feature-transformation"><code>#transformation</code></a></td><td></td></tr></tbody></table><p>For the sake of convenience, the following table,
-<a href="#feature-presentation-mandatory-table"><b>Table E-3 – Mandatory Features - Presentation</b></a>, enumerates all
-mandatory features for a TTML <a href="#terms-presentation-processor">presentation processor</a>, providing additional
-comments to summarize the context of usage or the nature of the feature.
-The <a href="#terms-profile-definition-document">profile definition document</a> that defines the corresponding
-TTML Presentation Profile is specified in
-<a href="#profile-ttml2-presentation"><b>G.2 TTML2 Presentation Profile</b></a>.
-</p><a id="feature-presentation-mandatory-table"></a><table class="common"><caption>Table E-3 – Mandatory Features - Presentation</caption><col width="60%" span="1"><col width="40%" span="1"><tbody><tr><td><span class="strong">Feature</span></td><td><span class="strong">Comments</span></td></tr><tr><td><a href="#feature-content"><code>#content</code></a></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>,
-<a href="#content-vocabulary-br"><code>br</code></a>
-</td></tr><tr><td><a href="#feature-core"><code>#core</code></a></td><td>
-<a href="#content-attribute-xml-id">@<code>xml:id</code></a>,
-<a href="#content-attribute-xml-id">@<code>xml:lang</code></a>,
-<a href="#content-attribute-xml-id">@<code>xml:space</code></a>
-</td></tr><tr><td><a href="#feature-profile"><code>#profile</code></a></td><td></td></tr><tr><td><a href="#feature-presentation"><code>#presentation</code></a></td><td></td></tr><tr><td><a href="#feature-structure"><code>#structure</code></a></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</code></a>,
-<a href="#document-structure-vocabulary-head"><code>head</code></a>
-</td></tr><tr><td><a href="#feature-time-offset"><code>#time-offset</code></a></td><td></td></tr><tr><td><a href="#feature-timing"><code>#timing</code></a></td><td>
-<a href="#timing-attribute-begin">@<code>begin</code></a>,
-<a href="#timing-attribute-dur">@<code>dur</code></a>,
-<a href="#timing-attribute-end">@<code>end</code></a>
-</td></tr></tbody></table></div></div><div class="div1">
-<h2><a id="extensions"></a>F Extensions</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the syntactic form of extension designations, which are
-used to express authorial intent regarding the support for extension
-mechanisms in a TTML processor.</p><div class="div2">
-<h3><a id="extension-designations"></a>F.1 Extension Designations</h3><p>An extension designation is expressed as a string that adheres to the following
-form:</p><div class="exampleInner"><pre>
-extension-designation
-  : extension-namespace designation
-
-extension-namespace
-  : <em>TT Extension Namespace</em>                  // http://www.w3.org/ns/ttml/extension/
-  | <em>Other Extension Namespace</em>               // expressed as an absolute URI
-
-designation
-  : "#" token-char+
-
-token-char
-  : { XML NameChar }                        // XML 1.1 Production [4a]
-</pre></div><p>If the extension namespace of an extension designation is the TT
-Extension Namespace, then all values of the following
-<code>designation</code> token are reserved for future
-standardization.</p><p>If the extension namespace of an extension designation is not the
-TT Extension Namespace, i.e., is an <em>Other Extension Namespace</em>,
-then the extension namespace must be expressed as an absolute URI
-capable of serving as a base URI used in combination with a
-<code>designation</code> token that takes the form of a fragment
-identifier.</p></div></div><div class="div1">
-<h2><a id="standard-profiles"></a>G Standard Profiles</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the following standard TTML profiles:</p><ul><li><p><a href="#profile-ttml2-full"><b>G.1 TTML2 Full Profile</b></a></p></li><li><p><a href="#profile-ttml2-presentation"><b>G.2 TTML2 Presentation Profile</b></a></p></li><li><p><a href="#profile-ttml2-transformation"><b>G.3 TTML2 Transformation Profile</b></a></p></li></ul><p>Each TTML profile is defined in terms of a <a href="#terms-profile-definition-document">profile definition document</a>,
-which is expressed as an XML document wherein the root element adheres to
-<a href="#profile-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>.</p><div class="div2">
-<h3><a id="profile-ttml2-full"></a>G.1 TTML2 Full Profile</h3><p>The TTML2 Full Profile is intended to be used to
-express maximum compliance for both transformation and presentation processing.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This profile is a superset of the
-<a href="https://dvcs.w3.org/hg/ttml/raw-file/default/ttml1/spec/ttml1.html#profile-dfxp-full">DFXP Full Profile</a>:
-it requires support for the
-<a href="#feature-version"><code>#border</code></a>,
-<a href="#feature-version"><code>#textOrientation</code></a>, and
-<a href="#feature-version"><code>#version</code></a>
-features.</p></div><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;!-- this file defines the "dfxp-full" profile of ttml --&gt;
-&lt;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;!-- required (mandatory) feature support --&gt;
-    &lt;feature value="required"&gt;#animation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor-block&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor&lt;/feature&gt;
-    &lt;feature value="required"&gt;#bidi&lt;/feature&gt;
-    &lt;feature value="required"&gt;#border&lt;/feature&gt;
-    &lt;feature value="required"&gt;#cellResolution&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode-gps&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode-local&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode-utc&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#color&lt;/feature&gt;
-    &lt;feature value="required"&gt;#content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#core&lt;/feature&gt;
-    &lt;feature value="required"&gt;#direction&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display-block&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display&lt;/feature&gt;
-    &lt;feature value="required"&gt;#displayAlign&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode-dropNTSC&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode-dropPAL&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode-nonDrop&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#extent-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#extent-root&lt;/feature&gt;
-    &lt;feature value="required"&gt;#extent&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontFamily-generic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontFamily-non-generic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontFamily&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontSize-anamorphic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontSize-isomorphic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontSize&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontStyle-italic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontStyle-oblique&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontStyle&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontWeight-bold&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontWeight&lt;/feature&gt;
-    &lt;feature value="required"&gt;#frameRate&lt;/feature&gt;
-    &lt;feature value="required"&gt;#frameRateMultiplier&lt;/feature&gt;
-    &lt;feature value="required"&gt;#layout&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-cell&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-em&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-integer&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-negative&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-percentage&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-pixel&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-positive&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-real&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length&lt;/feature&gt;
-    &lt;feature value="required"&gt;#lineBreak-uax14&lt;/feature&gt;
-    &lt;feature value="required"&gt;#lineHeight&lt;/feature&gt;
-    &lt;feature value="required"&gt;#markerMode-continuous&lt;/feature&gt;
-    &lt;feature value="required"&gt;#markerMode-discontinuous&lt;/feature&gt;
-    &lt;feature value="required"&gt;#markerMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#metadata&lt;/feature&gt;
-    &lt;feature value="required"&gt;#nested-div&lt;/feature&gt;
-    &lt;feature value="required"&gt;#nested-span&lt;/feature&gt;
-    &lt;feature value="required"&gt;#opacity&lt;/feature&gt;
-    &lt;feature value="required"&gt;#origin&lt;/feature&gt;
-    &lt;feature value="required"&gt;#overflow-visible&lt;/feature&gt;
-    &lt;feature value="required"&gt;#overflow&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-1&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-2&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-3&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-4&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding&lt;/feature&gt;
-    &lt;feature value="required"&gt;#pixelAspectRatio&lt;/feature&gt;
-    &lt;feature value="required"&gt;#presentation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#profile&lt;/feature&gt;
-    &lt;feature value="required"&gt;#showBackground&lt;/feature&gt;
-    &lt;feature value="required"&gt;#structure&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-chained&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-inheritance-content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-inheritance-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-nested&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-referential&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling&lt;/feature&gt;
-    &lt;feature value="required"&gt;#subFrameRate&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textAlign-absolute&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textAlign-relative&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textAlign&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration-over&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration-through&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration-under&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOrientation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOutline-blurred&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOutline-unblurred&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOutline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#tickRate&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-clock-with-frames&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-clock&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset-with-frames&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset-with-ticks&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeBase-clock&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeBase-media&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeBase-smpte&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeContainer&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timing&lt;/feature&gt;
-    &lt;feature value="required"&gt;#transformation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#unicodeBidi&lt;/feature&gt;
-    &lt;feature value="required"&gt;#version&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility-block&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility&lt;/feature&gt;
-    &lt;feature value="required"&gt;#wrapOption&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-horizontal-lr&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-horizontal-rl&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-horizontal&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-vertical&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#zIndex&lt;/feature&gt;
-    &lt;!-- optional (voluntary) feature support --&gt;
-  &lt;/features&gt;
-  &lt;extensions xml:base="http://www.w3.org/ns/ttml/extension/"&gt;
-    &lt;!-- required (mandatory) extension support --&gt;
-    &lt;!-- optional (voluntary) extension support --&gt;
-  &lt;/extensions&gt;
-&lt;/profile&gt;
-
-</pre></div></div><div class="div2">
-<h3><a id="profile-ttml2-presentation"></a>G.2 TTML2 Presentation Profile</h3><p>The TTML2 Presentation Profile is intended to be used to
-express minimum compliance for presentation processing.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This profile is a superset of the
-<a href="https://dvcs.w3.org/hg/ttml/raw-file/default/ttml1/spec/ttml1.html#profile-dfxp-presentation">DFXP Presentation Profile</a>:
-it requires support for the <a href="#feature-version"><code>#version</code></a> feature.</p></div><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;!-- this file defines the "dfxp-presentation" profile of ttml --&gt;
-&lt;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;!-- required (mandatory) feature support --&gt;
-    &lt;feature value="required"&gt;#content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#core&lt;/feature&gt;
-    &lt;feature value="required"&gt;#presentation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#profile&lt;/feature&gt;
-    &lt;feature value="required"&gt;#structure&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timing&lt;/feature&gt;
-    &lt;feature value="required"&gt;#version&lt;/feature&gt;
-    &lt;!-- optional (voluntary) feature support --&gt;
-    &lt;feature value="optional"&gt;#animation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#bidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#border&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#cellResolution&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-gps&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-local&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-utc&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#color&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#direction&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#displayAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropNTSC&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropPAL&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-nonDrop&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-root&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-non-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-anamorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-isomorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-italic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-oblique&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight-bold&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRateMultiplier&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#layout&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-cell&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-em&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-integer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-negative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-percentage&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-pixel&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-positive&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-real&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineBreak-uax14&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineHeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-continuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-discontinuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#metadata&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-div&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-span&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#opacity&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#origin&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow-visible&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-1&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-2&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-3&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-4&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#pixelAspectRatio&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#showBackground&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-chained&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-content&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-nested&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-referential&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#subFrameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-absolute&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-relative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-over&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-through&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-under&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOrientation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-blurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-unblurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#tickRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-ticks&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-media&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-smpte&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeContainer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#transformation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#unicodeBidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#wrapOption&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-lr&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-rl&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-vertical&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#zIndex&lt;/feature&gt;
-  &lt;/features&gt;
-  &lt;extensions xml:base="http://www.w3.org/ns/ttml/extension/"&gt;
-    &lt;!-- required (mandatory) extension support --&gt;
-    &lt;!-- optional (voluntary) extension support --&gt;
-  &lt;/extensions&gt;
-&lt;/profile&gt;
-
-</pre></div></div><div class="div2">
-<h3><a id="profile-ttml2-transformation"></a>G.3 TTML2 Transformation Profile</h3><p>The TTML2 Transformation Profile is intended to be used to
-express minimum compliance for transformation processing.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This profile is a superset of the
-<a href="https://dvcs.w3.org/hg/ttml/raw-file/default/ttml1/spec/ttml1.html#profile-dfxp-transformation">DFXP Transformation Profile</a>:
-it requires support for the <a href="#feature-version"><code>#version</code></a> feature.</p></div><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;!-- this file defines the "dfxp-transformation" profile of ttml --&gt;
-&lt;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;!-- required (mandatory) feature support --&gt;
-    &lt;feature value="required"&gt;#content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#core&lt;/feature&gt;
-    &lt;feature value="required"&gt;#profile&lt;/feature&gt;
-    &lt;feature value="required"&gt;#structure&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timing&lt;/feature&gt;
-    &lt;feature value="required"&gt;#transformation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#version&lt;/feature&gt;
-    &lt;!-- optional (voluntary) feature support --&gt;
-    &lt;feature value="optional"&gt;#animation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#bidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#border&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#cellResolution&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-gps&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-local&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-utc&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#color&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#direction&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#displayAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropNTSC&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropPAL&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-nonDrop&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-root&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-non-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-anamorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-isomorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-italic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-oblique&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight-bold&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRateMultiplier&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#layout&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-cell&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-em&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-integer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-negative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-percentage&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-pixel&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-positive&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-real&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineBreak-uax14&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineHeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-continuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-discontinuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#metadata&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-div&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-span&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#opacity&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#origin&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow-visible&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-1&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-2&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-3&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-4&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#pixelAspectRatio&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#presentation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#showBackground&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-chained&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-content&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-nested&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-referential&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#subFrameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-absolute&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-relative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-over&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-through&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-under&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOrientation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-blurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-unblurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#tickRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-ticks&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-media&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-smpte&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeContainer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#unicodeBidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#wrapOption&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-lr&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-rl&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-vertical&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#zIndex&lt;/feature&gt;
-  &lt;/features&gt;
-  &lt;extensions xml:base="http://www.w3.org/ns/ttml/extension/"&gt;
-    &lt;!-- required (mandatory) extension support --&gt;
-    &lt;!-- optional (voluntary) extension support --&gt;
-  &lt;/extensions&gt;
-&lt;/profile&gt;
-
-</pre></div></div></div><div class="div1">
-<h2><a id="time-expression-semantics"></a>H Time Expression Semantics</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the semantics for interpreting time expressions in <a href="#terms-document-instance">document instances</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The phrase <em>local real time</em> as used below is intended to model a virtual real time clock in the document processing context, where
-<em>local</em> means in the immediate proximity of the implementation of this processing context. The intent
-of defining relationships with this virtual clock is to establish a locally valid physical realization of time for didactic purposes.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The phrase <em>play rate</em> as used below is intended to model a (possibly variable) parameter in the document processing context wherein
-the rate of playback (or interpretation) of time may artificially dilated or narrowed, for example, when slowing down or speeding up the rate of
-playback of a <a href="#terms-related-media-object">related media object</a>. Without loss of generality, the following discussion assumes a fixed play(back) rate. In the case of
-variable play rates, appropriate adjustments may need to be made to the resulting computations.</p></div><div class="div2">
-<h3><a id="time-expression-semantics-clock"></a>H.1 Clock Time Base</h3><p>When operating with the <code>clock</code> time base, the following semantics apply for interpreting time expressions,
-as defined by <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, and their relationship to media time and local real time.</p><p>The clock time base <span class="strong"><code>C</code></span> is related to local real time <span class="strong"><code>R</code></span>
-expressed in an arbitrary (implementation defined) epoch <span class="strong"><code>E</code></span>
-as follows:</p><a id="clock-time-and-real-time"></a><table class="semantics"><caption>TTML Semantics – Clock Time and Real Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-<code>R = C + epochOffset + discontinuityOffset</code>
-<br><br>
-where <code>C ∈ ℜ</code>, <code>0 ≤ C &lt; ∞</code>, <code>C</code> in seconds since the most immediately prior midnight of the reference clock base;
-<br><br>
-<code>epochOffset ∈ ℜ</code>, <code>0 ≤ epochOffset &lt; ∞</code>, <code>epochOffset</code> in seconds, with 0 being the beginning
-of epoch <code>E</code>, and where the value of <code>epochOffset</code> is determined from the computed value of the <code>ttp:clockMode</code> parameter
-as follows:
-<br><br>
-(1) if <code>local</code>, then the difference between the local real time at the most immediately prior local midnight and the local real time
-at the beginning of epoch <code>E</code>, expressed in seconds;
-<br><br>
-(2) if <code>gps</code>, then the difference between the GPS time at the most immediately prior GPS midnight
-and the GPS time at the beginning of epoch <code>E</code>, expressed in seconds;
-<br><br>
-(3) if <code>utc</code>, then the difference between the UTC time at the most immediately prior UTC midnight
-and the UTC time at the beginning of epoch <code>E</code>, expressed in seconds;
-<br><br>
-<code>discontinuityOffset ∈ ℜ</code>, <code>−∞ &lt; discontinuityOffset &lt; ∞</code>, <code>discontinuityOffset</code> in seconds,
-and where the value of <code>discontinuityOffset</code> is equal to the sum of leap seconds (and fractions thereof) that have been added (or subtracted) since the
-most immediately prior midnight in the reference clock base;
-<br><br>
-and <code>epochOffset</code> and <code>discontinuityOffset</code> are determined once and only once prior to the beginning of the <a href="#terms-root-temporal-extent">root temporal extent</a> such that
-during the period between value determination and the beginning of the <a href="#terms-root-temporal-extent">root temporal extent</a> there occurs no local midnight or reference clock base discontinuity.
-<br></p></blockquote>
-</td></tr></tbody></table><p>Time value expressions, as denoted by a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, are related to
-clock time <span class="strong"><code>C</code></span> as follows:</p><a id="time-expressions-and-clock-time"></a><table class="semantics"><caption>TTML Semantics – Time Expressions and Clock Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-If a time expression uses the <em>clock-time</em> form or an <em>offset-time</em> form that doesn't use the ticks (<code>t</code>) metric, then:
-<br><br>
-<code>C = 3600 * hours + 60 * minutes + seconds</code>
-<br><br>
-where
-<code>hours</code>,
-<code>minutes</code>,
-<code>seconds</code> components are extracted from time expression if present, or zero if not present.
-<br><br>
-Otherwise, if a time expression uses an <em>offset-time</em> form that uses the ticks (<code>t</code>) metric, then:
-<br><br>
-<code>C = ticks / tickRate</code>
-<br></p></blockquote>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The <em>frames</em> and <em>sub-frames</em> terms and the frames (<code>f</code>) metric of time expressions do not apply when using
-the <code>clock</code> time base.</p></div><p>The clock time base <span class="strong"><code>C</code></span> is independent of media time <span class="strong"><code>M</code></span>:</p><a id="clock-time-and-media-time"></a><table class="semantics"><caption>TTML Semantics – Clock Time and Media Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-<code>M ¬∝ C</code>
-<br></p></blockquote>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>That is to say, timing is disconnected from (not necessarily proportional to) media time when
-the <code>clock</code> time base is used. For example, if the media play rate is zero (0), media playback is suspended; however, timing coordinates
-will continue to advance according to the natural progression of clock time in direct proportion to the reference clock base. Furthermore, if the media play rate changes
-during playback, presentation timing is not affected.
-</p></div></div><div class="div2">
-<h3><a id="time-expression-semantics-media"></a>H.2 Media Time Base</h3><p>When operating with the <code>media</code> time base, the following semantics apply for interpreting time expressions,
-as defined by <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, and their relationship to media time and local real time.</p><div class="issue"><p class="prefix"><a id="issue-306"></a><b>Issue (issue-306):</b></p><p class="prefix"><b>Fractional Time Expressions</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/306">http://www.w3.org/AudioVideo/TT/tracker/issues/306</a></p><p>Augment syntax to cover fractional time expressions.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>The media time base <span class="strong"><code>M</code></span> is related to local real time <span class="strong"><code>R</code></span>
-expressed in an arbitrary (implementation defined) epoch <span class="strong"><code>E</code></span> as follows:</p><a id="media-time-and-real-time"></a><table class="semantics"><caption>TTML Semantics – Media Time and Real Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-<code>R = playRate * M + epochOffset</code>
-<br><br>
-where <code>M ∈ ℜ</code>, <code>0 ≤ M &lt; ∞</code>, <code>M</code> in seconds, with 0 corresponding to the beginning of the <a href="#terms-root-temporal-extent">root temporal extent</a>;
-<br><br>
-<code>playRate ∈ ℜ</code>, <code>−∞ &lt; playRate &lt; ∞</code>, <code>playRate</code> is unit-less, and where the value of
-<code>playRate</code> is determined by the document processing context;
-<br><br>
-and <code>epochOffset ∈ ℜ</code>, <code>0 ≤ epochOffset &lt; ∞</code>, <code>epochOffset</code> in seconds, with 0 corresponding to the beginning of
-an epoch <code>E</code>, and where the value of <code>epochOffset</code> is the difference between the local real time at the beginning of the
-<a href="#terms-root-temporal-extent">root temporal extent</a> and the local real time at the the beginning of epoch <code>E</code>, expressed in seconds.
-</p></blockquote>
-</td></tr></tbody></table><p>Time value expressions, as denoted by a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, are related to
-media time <span class="strong"><code>M</code></span> in accordance to the
-<code>ttp:frameRate</code>, <code>ttp:subFrameRate</code>, and <code>ttp:frameRateMultipler</code> parameters as follows:</p><a id="time-expressions-and-media-time"></a><table class="semantics"><caption>TTML Semantics – Time Expressions and Media Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-If a time expression uses a <em>clock-time</em> form or an <em>offset-time</em> form that doesn't use the ticks (<code>t</code>) metric, then:
-<br><br>
-<code>
-M = referenceBegin + 3600 * hours + 60 * minutes + seconds + ((frames + (subFrames / subFrameRate)) / effectiveFrameRate)
-</code>
-<br><br>
-where <code>referenceBegin</code> is determined according to whether the nearest ancestor time container employs
-parallel (<code>par</code>) or sequential (<code>seq</code>) semantics: if parallel or if sequential and no prior sibling
-timed element exists, then <code>referenceBegin</code>
-is the media time that corresponds to the beginning of the nearest ancestor time container or
-zero (0) if this time container is the <a href="#terms-root-temporal-extent">root temporal extent</a>; otherwise, if sequential and a prior sibling
-timed element exists, then <code>referenceBegin</code> is the media time that corresponds to the active end of the
-immediate prior sibling timed element;
-<br><br>
-the <code>hours</code>, <code>minutes</code>, <code>seconds</code>, <code>frames</code>, <code>subFrames</code> components
-are extracted from time expression if present, or zero if not present;
-<br><br>
-<code>subFrameRate</code> is the computed value of the <code>ttp:subFrameRate</code> parameter;
-<br><br>
-and <code>effectiveFrameRate</code> (in frames per second) is <code>frameRate * frameRateMultipler</code> where
-<code>frameRate</code> is the computed value of the <code>ttp:frameRate</code> parameter and
-<code>frameRateMultipler</code> is the computed value of the <code>ttp:frameRateMultiplier</code> parameter.
-<br><br>
-Otherwise, if a time expression uses an <em>offset-time</em> form that uses the ticks (<code>t</code>) metric, then:
-<br><br>
-<code>
-M = referenceBegin + ticks / tickRate
-</code>
-<br><br>
-where <code>referenceBegin</code> is as described above;
-<br><br>
-the <code>ticks</code> component is extracted from time expression;
-<br><br>
-and <code>tickRate</code> is the computed value of the <code>ttp:tickRate</code> parameter;
-<br></p></blockquote>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>If the computed <code>frameRateMultipler</code> ratio is not integral, then <code>effectiveFrameRate</code> will be a non-integral rational.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The begin time of the <a href="#terms-root-temporal-extent">root temporal extent</a> is related to the begin time of a
-<a href="#terms-related-media-object">related media object</a> in accordance with the computed value of the
-<a href="#parameter-attribute-mediaOffset"><code>ttp:mediaOffset</code></a> parameter property.</p></div></div><div class="div2">
-<h3><a id="time-expression-semantics-smpte"></a>H.3 SMPTE Time Base</h3><p>When operating with the <code>smpte</code> time base, the following semantics apply for interpreting time expressions,
-as defined by <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, and their relationship to media time and local real time.</p><div class="issue"><p class="prefix"><a id="issue-322"></a><b>Issue (issue-322):</b></p><p class="prefix"><b>Incorrect Expression for NTSC Drop Mode</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/322">http://www.w3.org/AudioVideo/TT/tracker/issues/322</a></p><p>Correct formula for NTSC drop mode calculation.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>If the computed value of the <code>ttp:markerMode</code> parameter is <code>discontinuous</code>, then there is no direct relationship between
-time expressions and media time <span class="strong"><code>M</code></span> or local real time <span class="strong"><code>R</code></span>. In
-this case, time expressions refer to synchronization events (markers) emitted by the <a href="#terms-document-processing-context">document processing context</a>
-when <a href="#terms-smpte-time-code">smpte time codes</a>
-are encountered in the <a href="#terms-related-media-object">related media object</a>.</p><p>Otherwise, if the computed value of the <code>ttp:markerMode</code> parameter is <code>continuous</code>, then the relationships between time expressions and
-local real time and media time are as described below in terms of a <a href="#terms-synthetic-smpte-document-syncbase">synthetic smpte document syncbase</a>, here referred to as the
-SMPTE time base <span class="strong"><code>S</code></span>.</p><a id="time-expressions-and-smpte-time"></a><table class="semantics"><caption>TTML Semantics – Time Expressions and SMPTE Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-<code>S = (countedFrames - droppedFrames + (subFrames / subFrameRate)) / effectiveFrameRate</code>
-<br><br>where<br><br>
-<code>countedFrames = (3600 * hours + 60 * minutes + seconds) * frameRate + frames</code>
-<br><br>
-<code>hours</code>, <code>minutes</code>, <code>seconds</code>, <code>frames</code>, <code>subFrames</code> components
-are extracted from time expression if present, or zero if not present;
-<br><br>
-<code>droppedFrames</code> is computed as follows:
-<br><br>
-1. let <em>dropMode</em> be the computed value of the <code>ttp:dropMode</code> parameter;
-<br><br>
-2. if <em>dropMode</em> is <code>dropNTSC</code>, let
-<code>droppedFrames = (hours * 54 + floor(minutes - minutes/10)) * 2</code>;
-<br><br>
-3. otherwise, if <em>dropMode</em> is <code>dropPAL</code>, let
-<code>droppedFrames = (hours * 27 + floor(minutes/2 - minutes/20)) * 4</code>;
-<br><br>
-4. otherwise, let
-<code>droppedFrames = 0</code>;
-<br><br>
-<code>frameRate</code> is the computed value of the <code>ttp:frameRate</code> parameter;
-<br><br>
-<code>subFrameRate</code> is the computed value of the <code>ttp:subFrameRate</code> parameter;
-<br><br>
-and <code>effectiveFrameRate</code> (in frames per second) is <code>frameRate * frameRateMultipler</code> where
-<code>frameRate</code> is the computed value of the <code>ttp:frameRate</code> parameter and
-<code>frameRateMultipler</code> is the computed value of the <code>ttp:frameRateMultiplier</code> parameter.
-<br><br>
-Notwithstanding the above, if a time expression contains a frame code that is designated as
-dropped according to <a href="#parameter-attribute-dropMode"><b>7.2.3 ttp:dropMode</b></a>, then that time expression
-must be considered to be invalid for purposes of validation assessment.
-<br></p></blockquote>
-</td></tr></tbody></table><p>The SMPTE time base <span class="strong"><code>S</code></span> is related to the media time base <span class="strong"><code>M</code></span> as follows:</p><a id="smpte-time-and-media-time"></a><table class="semantics"><caption>TTML Semantics – SMPTE Time and Media Time Relationship</caption><tbody><tr><td>
-<blockquote><p><br>
-<code>M = referenceBegin + S</code>
-<br><br>
-where <code>referenceBegin</code> is determined according to whether the nearest ancestor time container employs
-parallel (<code>par</code>) or sequential (<code>seq</code>) semantics: if parallel or if sequential and no prior sibling
-timed element exists, then <code>referenceBegin</code>
-is the SMPTE time that corresponds to the beginning of the nearest ancestor time container or
-zero (0) if this time container is the <a href="#terms-root-temporal-extent">root temporal extent</a>; otherwise, if sequential and a prior sibling
-timed element exists, then <code>referenceBegin</code> is the SMPTE time that corresponds to the active end of the
-immediate prior sibling timed element;
-<br></p></blockquote>
-</td></tr></tbody></table><p>Given the derived media time base as described above, then 
-media time base <span class="strong"><code>M</code></span> is related to the local real time <span class="strong"><code>R</code></span>
-as described in <a href="#time-expression-semantics-media"><b>H.2 Media Time Base</b></a> above.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The begin time of the <a href="#terms-root-temporal-extent">root temporal extent</a> is related to the begin time of a
-<a href="#terms-related-media-object">related media object</a> in accordance with the computed value of the
-<a href="#parameter-attribute-mediaOffset"><code>ttp:mediaOffset</code></a> parameter property.</p></div></div></div><div class="div1">
-<h2><a id="isd"></a>I Intermediate Document Syntax</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the syntactic elements and structure of a
-<a href="#terms-timed-text-intermediate-document">timed text intermediate document</a>.
-An ISD instance may be represented as a standalone document instance or
-in a collection represented as an ISD Sequence instance.</p><p>All ISD related vocabulary is defined in the TTML ISD Namespace, defined here as <code>http://www.w3.org/ns/ttml#isd</code>,
-where the recommended prefix is <code>isd</code>.</p><p>A TTML <a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a>, in short, an <em>ISD</em> or <em>ISD instance</em>,
-represents a discrete, temporally non-overlapping interval, an <em>ISD interval</em>,
-of a source TTML document where, except for non-discrete animation, all content, styling, and layout information remains static within that interval.
-In particular, the timing hierarchy of a TTML document is flattened and then sub-divided into temporally non-overlapping intervals, where each such
-interval defines a static view of the source TTML document within that interval, and where that static view is represented as an ISD instance.
-A concrete, standalone instance of a TTML
-<a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a> must specify an
-<a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element as its root document element. When an instance of a
-<a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a> is included in a
-<a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a> instance, then the ISD instance is represented
-by an <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> child element of the root 
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>An ISD instance may contain one or more animate elements that denote continuous animation within the associated interval. Continuously animated styles are sub-divided across
-ISD interval boundaries such that their step-wise concatenation expresses an equivalent continuous animation over any intersecting ISD interval(s).</p></div><p>A TTML <a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a> represents a collection
-of temporally non-overlapping <a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a> instances ordered according
-to their begin times. A concrete instance of a TTML
-<a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a> must specify an
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element as its root document element.</p><div class="div2">
-<h3><a id="isd-vocabulary"></a>I.1 ISD Vocabulary</h3><div class="div3">
-<h4><a id="isd-vocabulary-sequence"></a>I.1.1 isd:sequence</h4><p>The <code>isd:sequence</code> element serves as the root document element of an <a href="#terms-intermediate-synchronic-document-sequence">Intermediate
-Synchronic Document Sequence</a>  document.</p><p>The <code>isd:sequence</code> element accepts as its children zero or more elements in the
-<a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or one <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element,
-followed by zero or more <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> elements.</p><p>Child <code>isd:isd</code> elements must be ordered in accordance to the media time equivalent of their
-begin time; furthermore, the temporal intervals of any two child <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> elements must not overlap (in time).</p><a id="elt-syntax-isd-sequence"></a><table class="syntax"><caption>XML Representation – Element Information Item: isd:sequence</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;isd:sequence
-  size = <a href="http://www.w3.org/TR/xmlschema-2/#nonNegativeInteger">xsd:nonNegativeInteger</a>
-  version = <a href="http://www.w3.org/TR/xmlschema-2/#positiveInteger">xsd:positiveInteger</a>
-  <a href="#content-attribute-xml-lang"><span class="reqattr">xml:lang</span></a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  {<em>any attribute in the <a href="#isd-parameter-attribute-set">ISD Parameter Attribute Set</a></em>}&gt;
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#profile-vocabulary-profile">ttp:profile</a>?, <a href="#isd-vocabulary-isd">isd:isd</a>*
-&lt;/isd:sequence&gt;
-</pre></div>
-</td></tr></tbody></table><p>If the <code>size</code> attribute is specified, then it must be a non-negative integer corresponding to the number of
-<a href="#isd-vocabulary-isd"><code>isd:isd</code></a> child elements.
-If not specified, then the size must be considered to be <em>indefinite</em>, unless and until the
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element is terminated, in which case the size
-may be determined by inspection.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The <code>size</code> attribute would normally be omitted in the case of real time captioning.</p></div><p>If the <code>version</code> attribute is specified, then it must be a positive integer corresponding to the version of this
-<a href="#terms-intermediate-synchronic-document-syntax">Intermediate Synchronic Document Syntax</a> specification used in authoring
-the ISD sequence document. If specified, the numeric value must be greater than or equal to two (2). If not specified, then the version must be
-consider to be equal to two (2). The version associated with this
-<a href="#terms-intermediate-synchronic-document-sequence-syntax">Intermediate Synchronic Document Sequence Syntax</a> specification is two (2).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The ISD abstraction referred to or implied by <a href="#ttml1">[TTML1]</a> §9.3.2 was not concretely defined by that specification. Here we reserve version one (1)
-for informal discussion of that earlier abstraction and its various (non-standardized) realizations.</p></div><p>An <a href="#content-attribute-xml-lang"><code>xml:lang</code></a> attribute must be specified on the
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element.
-If its value is empty, it signifies that there is no default language that applies
-to the content within the <a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a>. Otherwise,
-the specified value denotes the default language that applies to each constituent
-<a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a>.</p><p>One or more parameter properties may be specified from the restricted parameter attribute set enumerated in <a href="#isd-parameter-attribute-set"><b>I.2 ISD Parameter Attribute Set</b></a>.
-If specified, then they apply globally to each constituent <a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a>.</p><p>If a child <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element is present,
-then that <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element must satisfy the following constraints:</p><ul><li><p>no <code>combine</code> attribute is specified;</p></li><li><p>no <code>designator</code> attribute is specified;</p></li><li><p>no <code>type</code> attribute is specified;</p></li><li><p>no <code>use</code> attribute is specified;</p></li><li><p>no descendant element is a <code>ttp:profile</code> element;</p></li><li><p>no descendant <code>ttp:feature</code> element specifies a <code>value</code> attribute with the value <code>prohibited</code>;</p></li><li><p>no descendant <code>ttp:extension</code> element specifies a <code>value</code> attribute with the value <code>prohibited</code>.</p></li></ul><p>Furthermore, such a child <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element must specify a profile that is equivalent to the combined
-<a href="#terms-processor-profile">processor profile</a> of the source TTML document having fetched all externally referenced profile documents.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The intent of permitting a single <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> to be specified in an
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> is to provide a simplified mechanism to declare
-processor profile requirements that must be met in order to process the document (in the absence of an end-user override).</p></div></div><div class="div3">
-<h4><a id="isd-vocabulary-isd"></a>I.1.2 isd:isd</h4><p>The <code>isd:isd</code> element serves either as (1) the root document element of a standalone <a href="#terms-intermediate-synchronic-document">Intermediate
-Synchronic Document</a> or (2) as a child of an <a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element of a
-<a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a> document.</p><p>The <code>isd:isd</code> element accepts as its children zero or more elements in the
-<a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or one <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element,
-followed by zero or more <a href="#isd-vocabulary-css"><code>isd:css</code></a> elements,
-followed by zero or more <a href="#isd-vocabulary-region"><code>isd:region</code></a> elements.</p><a id="elt-syntax-isd"></a><table class="syntax"><caption>XML Representation – Element Information Item: isd:isd</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;isd:isd
-  <a href="#timing-attribute-begin"><span class="reqattr">begin</span></a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end"><span class="reqattr">end</span></a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  version = <a href="http://www.w3.org/TR/xmlschema-2/#positiveInteger">xsd:positiveInteger</a>
-  <a href="#content-attribute-xml-lang">xml:lang</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  {<em>any attribute in the <a href="#isd-parameter-attribute-set">ISD Parameter Attribute Set</a></em>}&gt;
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#profile-vocabulary-profile">ttp:profile</a>?, <a href="#isd-vocabulary-css">isd:css</a>*, <a href="#isd-vocabulary-region">isd:region</a>*
-&lt;/isd:isd&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>begin</code> attribute must be specified, the value of which must take the <em>offset-time</em> form of
-a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, and, further, is restricted to use a metric of
-<code>s</code> (seconds),
-<code>f</code> (frames),
-<code>t</code> (ticks), or may omit the metric, in which case <code>s</code> seconds is implied. This
-begin time is expressed as an offset from the begin time of the <a href="#terms-root-temporal-extent">root temporal extent</a>
-of the source TTML document from which this <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element was derived.</p><p>An <code>end</code> attribute must be similarlly specified, where the same constraints apply.
-This end time is expressed as an offset from the begin time of the <a href="#terms-root-temporal-extent">root temporal extent</a>
-of the source TTML document from which this <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element was derived.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Expressed in the terminology of <a href="#smil3">[SMIL 3.0]</a>, the values of these <code>begin</code> and <code>end</code> attributes
-correspond to the resolved begin and end times of the <em>active duration</em> with respect to the <em>document begin</em>.</p></div><p>An <a href="#content-attribute-xml-lang"><code>xml:lang</code></a> attribute must be specified on the
-<a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element if it is a standalone <a href="#terms-intermediate-synchronic-document">Intermediate
-Synchronic Document</a> document; otherwise, it may be specified, and should be specified if the default language of the 
-<a href="#isd-vocabulary-sequence"><code>isd:isd</code></a> element differs from the default language of its
-parent <a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element.
-If its value is empty, it signifies that there is no default language that applies
-to the content within the <a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a>. Otherwise,
-the specified value denotes the default language that applies.</p><p>The <code>version</code> attribute follows the syntax and semantics of the same named attribute on the
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element type. The <code>version</code>
-attribute must not be specified on an <a href="#isd-vocabulary-isd">isd:isd</a> element that is not
-a root document element, i.e., is a child element of an <a href="#isd-vocabulary-sequence">isd:sequence</a> element.</p><p>A child <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element may be present if the
-<a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element is a standalone <a href="#terms-intermediate-synchronic-document">Intermediate
-Synchronic Document</a> document, in which case the same constraints and semantics apply as specified in <a href="#isd-vocabulary-sequence"><b>I.1.1 isd:sequence</b></a>;
-otherwise, if not a standalone document, a child <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element must not be present.</p></div><div class="div3">
-<h4><a id="isd-vocabulary-css"></a>I.1.3 isd:css</h4><p>The <code>isd:css</code> element is used to represent a unique computed style set of some collection of elements
-that share the same set of computed styles. In particular, for each
-element <em>E</em> in the source TTML document which is selected and copied into a
-<a href="#isd-vocabulary-region"><code>isd:region</code></a> element of a given
-<a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a>, the computed style
-set of <em>E</em>, <em>CSS(E)</em>, is determined, and, if that <em>CSS(E)</em> is not already specified
-by an existing <code>isd:css</code> element, then it is assigned a unique identifier and instantiated as a new
-<code>isd:css</code> element.</p><p>The <code>isd:css</code> element accepts as its children zero or more elements in the
-<a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group.</p><a id="elt-syntax-isd-style"></a><table class="syntax"><caption>XML Representation – Element Information Item: isd:css</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;isd:css
-  <a href="#content-attribute-xml-id"><span class="reqattr">xml:id</span></a> = ID
-  {<em>any attribute in TT Style namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*
-&lt;/isd:css&gt;
-</pre></div>
-</td></tr></tbody></table><p>For each arbitrary pair of <code>isd:css</code> child elements of an
-<a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element,
-<em>S1</em> and <em>S2</em>, the set of specified styles of <em>S1</em> must
-not be the same as the set of specified styles of <em>S2</em>. For the purpose of comparing two
-sets of specified styles, the styles must be placed into a canonical order and then compared item
-by item for value equality, where the canonical order is in accordance to the qualified attribute name
-order, where each qualified name consists of a tuple <code>&lt;namespace URL, local name&gt;</code>,
-and such tuples are compared component-wise by case-sensitive lexical string order.</p></div><div class="div3">
-<h4><a id="isd-vocabulary-region"></a>I.1.4 isd:region</h4><p>The <code>isd:region</code> element is used to represent a layout and presentation region
-and the content selected into that region, where that content takes the form of a
-<a href="#document-structure-vocabulary-body">body</a> element and its descendant TTML content elements.</p><p>The <code>isd:region</code> element accepts as its children zero or more elements in the
-<a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
-followed by zero or more <a href="#animation-vocabulary-animate"><code>animate</code></a> elements,
-followed by exactly one <a href="#document-structure-vocabulary-body"><code>body</code></a> element.</p><a id="elt-syntax-isd-region"></a><table class="syntax"><caption>XML Representation – Element Information Item: isd:region</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;isd:region
-  <a href="#style-attribute-style">style</a> = IDREF
-  <a href="#metadata-attribute-role">ttm:role</a> = <a href="http://www.w3.org/TR/xmlschema-2/#string">xsd:string</a>
-  <a href="#content-attribute-xml-id"><span class="reqattr">xml:id</span></a> = ID
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#element-vocab-group-metadata">Metadata.class</a>*, <a href="#animation-vocabulary-animate">animate</a>*, <a href="#document-structure-vocabulary-body">body</a>
-&lt;/isd:region&gt;
-</pre></div>
-</td></tr></tbody></table><p>If the computed style set of the region represented by the <code>isd:region</code> element is not the
-set of initial style values that apply to <a href="#layout-vocabulary-region"><code>region</code></a>, then a
-<code>style</code> attribute must be specified which references an <a href="#isd-vocabulary-css"><code>isd:css</code></a> element that specifies the
-region's computed style set.</p><p>The following constraints apply to the <a href="#document-structure-vocabulary-body"><code>body</code></a> element
-and its descendant elements:</p><ul><li><p>no <code>animate</code> attribute is specified;</p></li><li><p>no <code>begin</code> attribute is specified;</p></li><li><p>no <code>dur</code> attribute is specified;</p></li><li><p>no <code>end</code> attribute is specified;</p></li><li><p>no <code>region</code> attribute is specified;</p></li><li><p>no <code>timeContainer</code> attribute is specified;</p></li><li><p>no attribute in the TT Style namespace is specified;</p></li><li><p>no <a href="#animation-vocabulary-set">set</a> element is present;</p></li><li><p>no significant text node, i.e., text node in a #PCDATA context, is not contained in a 
-<a href="#content-vocabulary-span"><code>span</code></a> element that contains no other child.</p></li></ul><p>In addition, for the <a href="#document-structure-vocabulary-body"><code>body</code></a> element <em>B</em> and
-each of its descendant content elements <em>C</em>, if the computed style set of <em>B</em> or each <em>C</em> is
-not equal to the computed style set of its parent element, then that element, <em>B</em> or <em>C</em>, must specify a <code>style</code>
-attribute that references an <a href="#isd-vocabulary-css"><code>isd:css</code></a> element that specifies the
-element's computed style set.</p></div></div><div class="div2">
-<h3><a id="isd-parameter-attribute-set"></a>I.2 ISD Parameter Attribute Set</h3><p>The following subset of the defined <a href="#attribute-vocab-group-parameters">Parameter Attributes</a>
-are available for use with an
-<a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> or
-<a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element as described above:</p><ul><li><p><a href="#parameter-attribute-cellResolution">ttp:cellResolution</a></p></li><li><p><a href="#parameter-attribute-frameRate">ttp:frameRate</a></p></li><li><p><a href="#parameter-attribute-frameRateMultiplier">ttp:frameRateMultipler</a></p></li><li><p><a href="#parameter-attribute-mediaOffset">ttp:mediaOffset</a></p></li><li><p><a href="#parameter-attribute-pixelAspectRatio">ttp:pixelAspectRatio</a></p></li><li><p><a href="#parameter-attribute-subFrameRate">ttp:subFrameRate</a></p></li><li><p><a href="#parameter-attribute-tickRate">ttp:tickRate</a></p></li></ul></div><div class="div2">
-<h3><a id="isd-interchange"></a>I.3 ISD Interchange</h3><p>A concrete document instance that employs the <a href="#isd">Intermediate Synchronic Document Syntax</a> must be
-encoded as a well-formed <a href="#xml10">[XML 1.0]</a> document using the UTF-8 character encoding. Furthermore, such a document must specify
-an <a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element or
-an <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element as the root document element.</p><p>When a resource consisting of a concrete ISD Sequence or ISD instance is interchanged and a media type is used to identify the content type
-of that resource, then the media type <code>application/ttml+xml</code> should be used, about which see <a href="#ttml1">[TTML1]</a> Appendix C.
-If this media type is used, the optional <code>profile</code> parameter must not be specified, or, if specified, must be ignored by a processor.</p></div><div class="div2">
-<h3><a id="isd-examples"></a>I.4 ISD Examples</h3><p><em>This sub-section is non-normative.</em></p><table border="1" class="ednote" summary="Editorial note: Add ISD Examples"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Add ISD Examples</b></td><td align="right" valign="top">2014-09-22</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add worked out examples of ISD Sequence and ISD document instances.</td></tr></table></div></div><div class="div1">
-<h2><a id="references"></a>J References</h2><p><em>This appendix is normative.</em></p><dl><dt class="label"><a id="css2"></a>CSS2</dt><dd>Bert Bos et al.,
-<a href="http://www.w3.org/TR/2011/REC-CSS2-20110607/"><cite>Cascading
-Style Sheets, Level 2 Revision 1</cite></a>, W3C Recommendation, 07 June 2011.
-(See <a href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">http://www.w3.org/TR/2011/REC-CSS2-20110607/</a>.)
-</dd><dt class="label"><a id="css3-color"></a>CSS3 Color</dt><dd>Tantek Çelik and Chris Lilley,
-<a href="http://www.w3.org/TR/2011/REC-css3-color-20110607/"><cite>CSS Color
-Module Level 3</cite></a>, W3C Recommendation, 07 June 2011. (See
-<a href="http://www.w3.org/TR/2011/REC-css3-color-20110607/">http://www.w3.org/TR/2011/REC-css3-color-20110607/</a>.)
-</dd><dt class="label"><a id="data-encodings"></a>Data Encodings</dt><dd>S. Josefsson,
-<a href="http://www.rfc-editor.org/rfc/rfc4648.txt"><cite>The Base16, Base32, and Base64 Data Encodings</cite></a>,
-RFC 4648, October 2006, IETF. (See
-<a href="http://www.rfc-editor.org/rfc/rfc4648.txt">http://www.rfc-editor.org/rfc/rfc4648.txt</a>.)
-</dd><dt class="label"><a id="gps"></a>GPS</dt><dd>
-<a href="http://www.gps.gov/technical/"><cite>Global
-Positioning System</cite></a>, US Air Force.
-(See
-<a href="http://www.gps.gov/technical/">http://www.gps.gov/technical/</a>.)
-</dd><dt class="label"><a id="html5"></a>HTML5</dt><dd>Ian Hickson et al.,
-<a href="http://www.w3.org/TR/2014/REC-html5-20141028/"><cite>HTML5 A vocabulary and associated APIs for HTML and XHTML</cite></a>,
-W3C Recommendation, 28 October 2014. (See
-<a href="http://www.w3.org/TR/2014/REC-html5-20141028/">http://www.w3.org/TR/2014/REC-html5-20141028/</a>.)
-</dd><dt class="label"><a id="media-queries"></a>Media Queries</dt><dd>Florian Rivoal,,
-<a href="http://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/"><cite>Media Queries</cite></a>, W3C Recommendation, 19 June 2012. (See
-<a href="http://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/">http://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/</a>.)
-</dd><dt class="label"><a id="mime"></a>MIME</dt><dd>Ned Freed and Nathaniel Borenstein,  
-<a href="http://www.rfc-editor.org/rfc/rfc2045.txt"><cite>Multipurpose Internet
-Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite></a>,
-RFC 2045, November 1996, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc2045.txt">http://www.rfc-editor.org/rfc/rfc2045.txt</a>.)
-</dd><dt class="label"><a id="media-types"></a>MIME Media Types</dt><dd>Ned Freed and Nathaniel Borenstein,  
-<a href="http://www.rfc-editor.org/rfc/rfc2046.txt"><cite>Multipurpose Internet
-Mail Extensions (MIME) Part Two: Media Types</cite></a>,
-RFC 2046, November 1996, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc2046.txt">http://www.rfc-editor.org/rfc/rfc2046.txt</a>.)
-</dd><dt class="label"><a id="rng"></a>RELAX NG</dt><dd>ISO/IEC 19757-2,
-<a href="http://www.iso.org/"><cite>Information technology – Document
-Schema Definition Language (DSDL) – Part 2: Regular-grammar-based validation – RELAX NG</cite></a>,
-International Organization for Standardization (ISO).
-</dd><dt class="label"><a id="ruby"></a>Ruby</dt><dd>Masayasu Ishikawa et al.,
-<a href="http://www.w3.org/TR/2001/REC-ruby-20010531/"><cite>Ruby Annotation</cite></a>
-W3C Recommendation, 31 May 2001.
-(See <a href="http://www.w3.org/TR/2001/REC-ruby-20010531/">http://www.w3.org/TR/2001/REC-ruby-20010531/</a>.)
-</dd><dt class="label"><a id="smil3"></a>SMIL 3.0</dt><dd>Dick Bultermann, et al.,
-<a href="http://www.w3.org/TR/2008/REC-SMIL3-20081201/"><cite>Synchronized
-Multimedia Integration Language (SMIL 3.0)</cite></a>,
-W3C Recommendation, 1 December 2008. (See
-<a href="http://www.w3.org/TR/2008/REC-SMIL3-20081201/">http://www.w3.org/TR/2008/REC-SMIL3-20081201/</a>.)
-</dd><dt class="label"><a id="smpte12m"></a>SMPTE 12M</dt><dd>ANSI/SMPTE 12M,
-<a href="https://www.smpte.org/"><cite>Television, Audio and Film –
-Time and Control Code</cite></a>, SMPTE Standard.
-</dd><dt class="label"><a id="srgb"></a>SRGB</dt><dd>IEC 61966-2-1,
-<a href="http://www.iec.ch/"><cite>Multimedia
-systems and equipment – Colour measurement and management
-– Part 2-1: Colour management – Default RGB colour space
-– sRGB</cite></a>, International Electrotechnical
-Commission (IEC).
-</dd><dt class="label"><a id="svg11"></a>SVG 1.1</dt><dd>Erik Dahlström et al., Eds.,
-<a href="http://www.w3.org/TR/2011/REC-SVG11-20110816/"><cite>Scalable
-Vector Graphics (SVG) 1.1 Second Edition</cite></a>, W3C Recommendation, 16
-August 2011. (See
-<a href="http://www.w3.org/TR/2011/REC-SVG11-20110816/">http://www.w3.org/TR/2011/REC-SVG11-20110816/</a>.)
-</dd><dt class="label"><a id="uaag"></a>UAAG</dt><dd>Ian Jacobs, Jon Gunderson, and Eric Hansen, Eds.,
-<a href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/"><cite>User
-Agent Accessibility Guidelines 1.0</cite></a>, W3C Recommendation, 17
-December 2002. (See
-<a href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/">http://www.w3.org/TR/2002/REC-UAAG10-20021217/</a>.)
-</dd><dt class="label"><a id="uax14"></a>UAX14</dt><dd>Asmus Freytag, <a href="http://www.unicode.org/reports/tr14/tr14-17.html"><cite>Line Breaking
-Properties</cite></a>, Unicode Consortium, 29 August 2005. (See
-<a href="http://www.unicode.org/reports/tr14/tr14-17.html">http://www.unicode.org/reports/tr14/tr14-17.html</a>.)
-</dd><dt class="label"><a id="uri"></a>URI</dt><dd>T. Berner-Lee, R. Fielding, and L. Masinter,
-<a href="http://www.rfc-editor.org/rfc/rfc2396.txt"><cite>Uniform Resource Identifiers (URI): Generic Syntax</cite></a>,
-RFC 2396, August 1998, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc2396.txt">http://www.rfc-editor.org/rfc/rfc2396.txt</a>.)
-</dd><dt class="label"><a id="utc"></a>UTC</dt><dd>
-Recommendation TF.460,
-<a href="http://www.itu.int/"><cite>Standard-Frequency and Time-Signal
-Emissions</cite></a>, International
-Telecommunciations Union, Radio Sector (ITU-R).
-</dd><dt class="label"><a id="wcag"></a>WCAG</dt><dd>Ben Caldwell, et al., Eds.,
-<a href="http://www.w3.org/TR/2008/REC-WCAG20-20081211/"><cite>Web
-Content Accessibility Guidelines (WCAG) 2.0</cite></a>, W3C Recommendation, 11 December 2008. (See
-<a href="http://www.w3.org/TR/2008/REC-WCAG20-20081211/">http://www.w3.org/TR/2008/REC-WCAG20-20081211/</a>.)
-</dd><dt class="label"><a id="xlink11"></a>XLink 1.1</dt><dd>Steve DeRose, et al.
-<a href="http://www.w3.org/TR/2010/REC-xlink11-20100506/"><cite>XML Linking Language (XLink) Version 1.1</cite></a>,
-W3C Recommendation, 06 May 2010. (See
-<a href="http://www.w3.org/TR/2010/REC-xlink11-20100506/">http://www.w3.org/TR/2010/REC-xlink11-20100506/</a>.)
-</dd><dt class="label"><a id="xml10"></a>XML 1.0</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/2008/REC-xml-20081126/"><cite>Extensible Markup Language (XML)
-1.0 (Fifth Edition)</cite></a>, W3C Recommendation, 26 November 2008. (See
-<a href="http://www.w3.org/TR/2008/REC-xml-20081126/">http://www.w3.org/TR/2008/REC-xml-20081126/</a>.)
-</dd><dt class="label"><a id="xml11"></a>XML 1.1</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/2006/REC-xml11-20060816/"><cite>Extensible Markup Language (XML)
-1.1 (Second Edition)</cite></a>, W3C Recommendation, 16 August 2006, edited in place 29 September 2006. (See
-<a href="http://www.w3.org/TR/2006/REC-xml11-20060816/">http://www.w3.org/TR/2006/REC-xml11-20060816/</a>.)
-</dd><dt class="label"><a id="xmlbase"></a>XML Base</dt><dd>Jonathan Marsh and Richard Tobin, Eds.,
-<a href="http://www.w3.org/TR/2009/REC-xmlbase-20090128/"><cite>XML Base (Second Edition)</cite></a>,
-W3C Recommendation, 28 January 2009. (See
-<a href="http://www.w3.org/TR/2009/REC-xmlbase-20090128/">http://www.w3.org/TR/2009/REC-xmlbase-20090128/</a>.)
-</dd><dt class="label"><a id="xmlid"></a>XML ID</dt><dd>Jonathan Marsh, Daniel Veillard, Norman Walsh, Eds.,
-<a href="http://www.w3.org/TR/2005/REC-xml-id-20050909/"><cite>xml:id Version 1.0</cite></a>,
-W3C Recommendation, 09 September 2005. (See
-<a href="http://www.w3.org/TR/2005/REC-xml-id-20050909/">http://www.w3.org/TR/2005/REC-xml-id-20050909/</a>.)
-</dd><dt class="label"><a id="infoset"></a>XML InfoSet</dt><dd>John Cowan and Richard Tobin, Eds.,
-<a href="http://www.w3.org/TR/2004/REC-xml-infoset-20040204/"><cite>XML Information Set (Second Edition)</cite></a>,
-W3C Recommendation, 04 February 2004. (See
-<a href="http://www.w3.org/TR/2004/REC-xml-infoset-20040204/">http://www.w3.org/TR/2004/REC-xml-infoset-20040204/</a>.)
-</dd><dt class="label"><a id="xml-media"></a>XML Media Types</dt><dd>Makato Murata, Simon St. Laurent,
-Kan Khon, Eds., <a href="http://www.rfc-editor.org/rfc/rfc3023.txt"><cite>XML Media Types</cite></a>,
-RFC 3023, January 2001, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc3023.txt">http://www.rfc-editor.org/rfc/rfc3023.txt</a>.)
-</dd><dt class="label"><a id="xmlns10"></a>XML Namespaces 1.0</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/2009/REC-xml-names-20091208/"><cite>Namespaces
-in XML 1.0 (Third Edition)</cite></a>, W3C Recommendation, 8 December 2009. (See
-<a href="http://www.w3.org/TR/2009/REC-xml-names-20091208/">http://www.w3.org/TR/2009/REC-xml-names-20091208/</a>.)
-</dd><dt class="label"><a id="xsd-1"></a>XML Schema Part 1</dt><dd>Henry S. Thompson, David Beech,
-Murray Maloney, Noah Mendelsohn, Eds.,
-<a href="http://www.w3.org/TR/xmlschema-1/"><cite>XML Schema Part 1: Structures</cite></a>,
-W3C Recommendation, 28 October 2004. (See
-<a href="http://www.w3.org/TR/xmlschema-1/">http://www.w3.org/TR/xmlschema-1/</a>.)
-</dd><dt class="label"><a id="xsd-2"></a>XML Schema Part 2</dt><dd>Paul Biron and Ashok Malhotra,
-<a href="http://www.w3.org/TR/xmlschema-2/"><cite>XML Schema Part 2: Datatypes</cite></a>,
-W3C Recommendation, 28 October 2004. (See
-<a href="http://www.w3.org/TR/xmlschema-2/">http://www.w3.org/TR/xmlschema-2/</a>.)
-</dd><dt class="label"><a id="xsl11"></a>XSL 1.1</dt><dd>Anders Berglund,
-<a href="http://www.w3.org/TR/2006/REC-xsl11-20061205/"><cite>Extensible Stylesheet Language (XSL) Version 1.1</cite></a>,
-W3C Recommendation, 05 December 2006. (See
-<a href="http://www.w3.org/TR/2006/REC-xsl11-20061205/">http://www.w3.org/TR/2006/REC-xsl11-20061205/</a>.)
-</dd></dl></div><div class="div1">
-<h2><a id="other-references"></a>K Other References (Non-Normative)</h2><dl><dt class="label"><a id="ccreq"></a>CC-DECODER-REQ</dt><dd><a href="http://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol4/pdf/CFR-2012-title47-vol4-sec79-101.pdf"><cite>Closed Caption Decoder
-Requirements for Analog Television Receivers</cite></a>,
-United States Code of Federal Regulations, Title 47, Volume 1, Part 79, § 79.101. (See
-<a href="http://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol4/pdf/CFR-2012-title47-vol4-sec79-101.pdf">http://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol4/pdf/CFR-2012-title47-vol4-sec79-101.pdf</a>.)
-</dd><dt class="label"><a id="cea608e"></a>CEA-608-E</dt><dd>
-EIA/CEA-608-E,
-<a href="http://www.ce.org/"><cite>Line 21 Data
-Services</cite></a>, EIA/CEA Standard,
-Consumer Electronics Association (CEA).
-</dd><dt class="label"><a id="cea708e"></a>CEA-708-E</dt><dd>
-CEA-708-D,
-<a href="http://www.ce.org/"><cite>Digital Television (DTV) Closed Captioning</cite></a>, CEA Standard,
-Consumer Electronics Association (CEA).
-</dd><dt class="label"><a id="css3-bb"></a>CSS Backgrounds and Borders</dt><dd>Bert Bos, Elika Etamad and Brad Kemper,
-<a href="http://dev.w3.org/csswg/css3-background/"><cite>CSS Backgrounds and Borders Module Level 3</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css3-background/">http://dev.w3.org/csswg/css-backgrounds/</a>.)
-</dd><dt class="label"><a id="css3-box"></a>CSS Box Model</dt><dd>Bert Bos, Anton Prowse,
-<a href="http://dev.w3.org/csswg/css-box-3/"><cite>CSS Basic Box Model</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css-box-3/">http://dev.w3.org/csswg/css-box-3/</a>.)
-</dd><dt class="label"><a id="css3-fonts"></a>CSS Fonts</dt><dd>John Daggett,
-<a href="http://dev.w3.org/csswg/css-fonts/"><cite>CSS Fonts Module Level 3</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css-fonts/">http://dev.w3.org/csswg/css-fonts/</a>.)
-</dd><dt class="label"><a id="css3-frag"></a>CSS Fragmentation</dt><dd>Rossen Atanassov and Elika Etemad,,
-<a href="http://dev.w3.org/csswg/css-break/"><cite>CSS Fragmentation Module Level 3</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css-break/">http://dev.w3.org/csswg/css-break/</a>.)
-</dd><dt class="label"><a id="cssruby"></a>CSS Ruby</dt><dd>Elika Etemad and Koji Ishii,
-<a href="http://dev.w3.org/csswg/css-ruby-1/"><cite>CSS Ruby Layout Module Level 1</cite></a>
-W3C Editor's Draft.
-(See <a href="http://dev.w3.org/csswg/css-ruby-1/">http://dev.w3.org/csswg/css-ruby-1/</a>.)
-</dd><dt class="label"><a id="css3-text"></a>CSS Text</dt><dd>Elika Etamad (aka fantasai) and Koji Ishii,
-<a href="http://dev.w3.org/csswg/css-text-3/"><cite>CSS Text Module Level 3</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css-text-3/">http://dev.w3.org/csswg/css-text-3/</a>.)
-</dd><dt class="label"><a id="css3-decoration"></a>CSS Text Decoration</dt><dd>Elika Etamad (aka fantasai) and Koji Ishii,
-<a href="http://dev.w3.org/csswg/css-text-decor-3/"><cite>CSS Text Decoration Module Level 3</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css-text-decor-3/">http://dev.w3.org/csswg/css-text-decor-3/</a>.)
-</dd><dt class="label"><a id="css3-wm"></a>CSS Writing Modes</dt><dd>Elika Etamad and Koji Ishii,
-<a href="http://dev.w3.org/csswg/css-writing-modes-3/"><cite>CSS Writing Modes Level 3</cite></a>, W3C Editor's Draft. (See
-<a href="http://dev.w3.org/csswg/css-writing-modes-3/">http://dev.w3.org/csswg/css-writing-modes-3/</a>.)
-</dd><dt class="label"><a id="dcmes"></a>DCMES 1.1</dt><dd>Dublin Core Metadata Initiative,
-<a href="http://dublincore.org/documents/dces/"><cite>Dublin Core Metadata Element Set, Version 1.1: Reference Description</cite></a>. (See
-<a href="http://dublincore.org/documents/dces/">http://dublincore.org/documents/dces/</a>.)
-</dd><dt class="label"><a id="jlreq"></a>JLREQ</dt><dd>Richard Ishida et al.,
-<a href="http://www.w3.org/TR/2012/NOTE-jlreq-20120403/"><cite>Requirements for Japanese Text Layout</cite></a>
-W3C Working Group Note, 3 April 2012.
-(See <a href="http://www.w3.org/TR/2012/NOTE-jlreq-20120403/">http://www.w3.org/TR/2012/NOTE-jlreq-20120403/</a>.)
-</dd><dt class="label"><a id="mpeg7-5"></a>MPEG7-5</dt><dd>
-ISO/IEC 15938-5,
-<a href="http://www.iso.org/"><cite>Information technology – Multimedia content description
-interface – Part 5: Multimedia description schemes</cite></a>,
-International Organization for Standardization (ISO).
-</dd><dt class="label"><a id="nsoriginal"></a>NSOriginal</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/1999/REC-xml-names-19990114/"><cite>Namespaces
-in XML</cite></a>, W3C Recommendation, 14 January 1999. (See
-<a href="http://www.w3.org/TR/1999/REC-xml-names-19990114/">http://www.w3.org/TR/1999/REC-xml-names-19990114/</a>.)
-</dd><dt class="label"><a id="nsstate"></a>NSState</dt><dd>Norman Walsh, Ed.,
-<a href="http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09.html"><cite>The Disposition
-of Names in an XML Namespace</cite></a>, TAG Finding, 9 January 2006. (See
-<a href="http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09.html">http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09</a>.)
-</dd><dt class="label"><a id="qaf-sg"></a>QAF SG</dt><dd>Karl Dubost, et al.,
-<a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/"><cite>QA
-Framework: Specifications Guidelines</cite></a>, W3C Recommendation, 17
-August 2005. (See
-<a href="http://www.w3.org/TR/qaframe-spec/">http://www.w3.org/TR/qaframe-spec/</a>.)
-</dd><dt class="label"><a id="sdpus"></a>SDP US</dt><dd>Glenn Adams, Monica Martin, Sean Hayes,
-<a href="http://www.w3.org/TR/2013/NOTE-ttml10-sdp-us-20130205/"><cite>TTML Simple Delivery Profile for Closed Captions (US)</cite></a>,
-W3C WG Note, 5 February 2013. (See
-<a href="http://www.w3.org/TR/2013/NOTE-ttml10-sdp-us-20130205/">http://www.w3.org/TR/2013/NOTE-ttml10-sdp-us-20130205/</a>.)
-</dd><dt class="label"><a id="smpte170m"></a>SMPTE 170M</dt><dd>ANSI/SMPTE 170M, 
-<a href="http://www.smpte.org/"><cite>Television – Composite Analog Video
-Signal – NTSC for Studio Applications</cite></a>, SMPTE Standard.
-</dd><dt class="label"><a id="smpte2052"></a>SMPTE 2052-11</dt><dd>SMPTE 2052-11,
-<a href="http://www.smpte.org/"><cite>Conversion from CEA-708 Caption Data to SMPTE-TT</cite></a>,
-SMPTE Recommended Practice.
-</dd><dt class="label"><a id="ttaf1-req"></a>TTAF1-REQ</dt><dd>Glenn Adams, Ed.,
-<a href="http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/"><cite>Timed Text (TT) Authoring Format 1.0 Use
-Cases and Requirements</cite></a>,
-W3C Working Group Note, 27 April 2006. (See
-<a href="http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/">http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/</a>.)
-</dd><dt class="label"><a id="ttml1"></a>TTML1</dt><dd>Glenn Adams, Ed.,
-<a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/"><cite>Timed Text Markup Language 1 (TTML1) (Second Edition)</cite></a>,
-W3C Recommendation, 24 September 2013. (See
-<a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/">http://www.w3.org/TR/2013/REC-ttml1-20130924/</a>.)
-</dd><dt class="label"><a id="xhtml10"></a>XHTML 1.0</dt><dd>Steven Pemberton, et al.,
-<a href="http://www.w3.org/TR/2002/REC-xhtml1-20020801/"><cite>XHTML™ 1.0,
-The Extensible Hypertext Markup Language (Second Edition)</cite></a>,
-W3C Recommendation, 01
-August 2002. (See
-<a href="http://www.w3.org/TR/2002/REC-xhtml1-20020801/">http://www.w3.org/TR/2002/REC-xhtml1-20020801/</a>.)
-</dd></dl></div><div class="div1">
-<h2><a id="requirements"></a>L Requirements (Non-Normative)</h2><p>The Timed Text Markup Language (TTML), also known as the Distribution Format Exchange Profile (DFXP) of the Timed Text Authoring
-Format (TTAF), satisfies a subset of the requirements established by
-<a href="#ttaf1-req">[TTAF1-REQ]</a>. The following table enumerates these requirements and
-indicates the extent to which they are satisfied by this specification, where
-<em>S</em> denotes a requirement is satisfied, <em>P</em> denotes
-a requirement is partially satisfied, and <em>N</em> denotes a
-requirement is not satisfied.</p><a id="requirements-table"></a><table class="common"><caption>Table L-1 – Requirement Satisfaction</caption><col width="10%" span="1"><col width="40%" span="1"><col width="10%" span="1"><col span="1"><tbody><tr><th>ID</th><th>Name</th><th>Status</th><th>Comments</th></tr><tr><td>R100</td><td>Specification Format</td><td>S</td><td></td></tr><tr><td>R101</td><td>Specification Modularity</td><td>S</td><td></td></tr><tr><td>R102</td><td>Specification Organization</td><td>S</td><td></td></tr><tr><td>R103</td><td>Core and Periphery</td><td>S</td><td>TT extension namespaces</td></tr><tr><td>R104</td><td>Evolution of Core</td><td>S</td><td>TT extension namespaces</td></tr><tr><td>R105</td><td>Ownership of Core</td><td>S</td><td>TT namespaces</td></tr><tr><td>R106</td><td>Surjection of Core</td><td>S</td><td></td></tr><tr><td>R107</td><td>Evolution of Periphery</td><td>S</td><td>TT extension namespaces</td></tr><tr><td>R108</td><td>Ownership of Periphery</td><td>S</td><td>Non-TT namespaces</td></tr><tr><td>R109</td><td>Transformation</td><td>S</td><td>Supports 3GPP, QText, RealText, SAMI</td></tr><tr><td>R110</td><td>Streamable Transformation</td><td>S</td><td>Progressive decoding</td></tr><tr><td>R111</td><td>Accessibility – Content</td><td>S</td><td>Alternative document instances</td></tr><tr><td>R112</td><td>Accessibility – Authoring System</td><td>S</td><td></td></tr><tr><td>R200</td><td>Authorability</td><td>S</td><td></td></tr><tr><td>R201</td><td>Multiple Natural Languages</td><td>S</td><td>Alternative document instances</td></tr><tr><td>R202</td><td>Natural Language Coverage</td><td>S</td><td>Unicode 4.0</td></tr><tr><td>R203</td><td>Natural Language Association Granularity</td><td>S</td><td>See <code>xml:lang</code></td></tr><tr><td>R204</td><td>Minimum Character Representability</td><td>S</td><td>Unicode 4.0</td></tr><tr><td>R205</td><td>Intrinsic and Extrinsic Text Content</td><td>P</td><td>Intrinsic only</td></tr><tr><td>R206</td><td>Markup Association</td><td>P</td><td>Intrinsic only</td></tr><tr><td>R207</td><td>Conditional Content</td><td>N</td><td></td></tr><tr><td>R208</td><td>Flowed Text</td><td>S</td><td></td></tr><tr><td>R209</td><td>Logical Flowed Text Vocabulary</td><td>S</td><td></td></tr><tr><td>R210</td><td>Presentational Flowed Text Vocabulary</td><td>S</td><td>Implied mapping from logical flowed text.</td></tr><tr><td>R211</td><td>Flowed Text Vocabulary Relationship</td><td>S</td><td></td></tr><tr><td>R212</td><td>Flowed Text Vocabulary Separation</td><td>N</td><td></td></tr><tr><td>R213</td><td>Non-Flowed Text</td><td>N</td><td></td></tr><tr><td>R214</td><td>Non-Flowed Text Vocabulary</td><td>N</td><td></td></tr><tr><td>R215</td><td>Hybrid Flowed and Non-Flowed Text</td><td>N</td><td></td></tr><tr><td>R216</td><td>Hyperlinking</td><td>N</td><td>Can support via XLink</td></tr><tr><td>R217</td><td>Embedded Graphics</td><td>N</td><td></td></tr><tr><td>R218</td><td>Non-Embedded Graphics</td><td>N</td><td></td></tr><tr><td>R219</td><td>Embedded Fonts</td><td>N</td><td></td></tr><tr><td>R220</td><td>Non-Embedded Fonts</td><td>N</td><td></td></tr><tr><td>R221</td><td>Descriptive Vocabulary</td><td>S</td><td>See <code>ttm:agent</code>, <code>ttm:role</code></td></tr><tr><td>R222</td><td>Embedded Audio</td><td>N</td><td></td></tr><tr><td>R223</td><td>Non-Embedded Audio</td><td>N</td><td></td></tr><tr><td>R290</td><td>Markup Format</td><td>S</td><td></td></tr><tr><td>R291</td><td>Markup Format and Unicode Interaction</td><td>S</td><td></td></tr><tr><td>R292</td><td>Extrinsic Resource References</td><td>N</td><td>No extrinsic references</td></tr><tr><td>R293</td><td>Schema Validity Specification</td><td>S</td><td></td></tr><tr><td>R300</td><td>Inline Styling</td><td>S</td><td></td></tr><tr><td>R301</td><td>Inline Styling Form</td><td>P</td><td>Inline and referential styling</td></tr><tr><td>R301</td><td>Out-of-Line Styling</td><td>N</td><td></td></tr><tr><td>R301</td><td>Out-of-Line Styling Form</td><td>N</td><td></td></tr><tr><td>R304</td><td>Styling Prioritization</td><td>S</td><td></td></tr><tr><td>R305</td><td>Style Parameters – Aural</td><td>N</td><td></td></tr><tr><td>R306</td><td>Style Parameters – Visual</td><td>P</td><td>Supports absolute position, background color, color, display none, display alignment,
-font family, font size, font style, font weight, height, line height, origin,
-opacity, overflow, padding (before, after, start, end), text alignment,
-text shadow (as outline), visibility, width, writing mode, z-index</td></tr><tr><td>R390</td><td>Style Parameter Symmetry</td><td>S</td><td></td></tr><tr><td>R391</td><td>Style Parameter Definitions</td><td>S</td><td></td></tr><tr><td>R392</td><td>Style Parameter Shorthands</td><td>S</td><td></td></tr><tr><td>R401</td><td>Inline Timing</td><td>S</td><td></td></tr><tr><td>R402</td><td>Out-of-Line Timing</td><td>N</td><td></td></tr><tr><td>R403</td><td>Synchronization Parameters</td><td>P</td><td>Supports begin, end, dur</td></tr><tr><td>R404</td><td>Synchronization Parameter Value Spaces</td><td>P</td><td>Supports offset values, media marker values (SMPTE 12M), wall-clock values</td></tr><tr><td>R405</td><td>Time Containment Semantics</td><td>P</td><td>Supports sequential, parallel</td></tr><tr><td>R500</td><td>Animation Modes</td><td>P</td><td>Supports discrete</td></tr><tr><td>R502</td><td>Highlight Animation</td><td>S</td><td><code>&lt;set tts:backgroundColor="..."/&gt;</code></td></tr><tr><td>R503</td><td>Fade Transition Animation</td><td>S</td><td><code>&lt;set tts:opacity="..."/&gt;</code></td></tr><tr><td>R504</td><td>Animated Style Parameters – Aural</td><td>N</td><td></td></tr><tr><td>R505</td><td>Animated Style Parameters – Visual</td><td>P</td><td>Supports animating background color, color, display, opacity, origin, visibility</td></tr><tr><td>N506</td><td>Animated Content</td><td>S</td><td></td></tr><tr><td>R600</td><td>Metadata Item Association</td><td>S</td><td>See <code>metadata</code>, <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a></td></tr><tr><td>R601</td><td>Metadata Item Constituents</td><td>P</td><td>Supports name, value</td></tr><tr><td>R602</td><td>Metadata Item Value Representation</td><td>P</td><td>See <code>metadata</code></td></tr><tr><td>R603</td><td>Metadata Item Extensibility</td><td>S</td><td>See <code>metadata</code></td></tr><tr><td>R604</td><td>Metadata Item Validation</td><td>S</td><td>See <code>metadata</code></td></tr><tr><td>R690</td><td>Dublin Core Preference</td><td>N</td><td>Uses <code>ttm:copyright</code>, <code>ttm:desc</code>, <code>ttm:title</code></td></tr></tbody></table></div><div class="div1">
-<h2><a id="derivation"></a>M Vocabulary Derivation (Non-Normative)</h2><p>This appendix provides information about the derivation of TTML
-vocabulary, separately describing derivation of elements and
-attributes.</p><table border="1" class="ednote" summary="Editorial note: Update Derivation"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Update Derivation</b></td><td align="right" valign="top">2015-01-14</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Update derivation tables to include new vocabulary added in TTML2.</td></tr></table><div class="div2">
-<h3><a id="d3e37582"></a>M.1 Element Derivation</h3><p>The first column of <a href="#element-vocab-derivation-table"><b>Table M-1 – Elements</b></a>
-specifies a TTML element vocabulary item; the second column specifies the
-syntactic and/or semantic model on which the vocabulary item is based;
-the third column specifies the reference that defines
-the model (if a model is indicated);
-the fourth column specifies details about the derivation; the last
-column refers to additional notes describing the nature of the
-derivation.</p><p>In the fourth column, which describes details of derivation, a
-notation is use to indicate the addition or removal of an attribute.
-For example, in the derivation of the <code>tt:div</code> element, the
-details column includes "-@class", which denotes that the
-<code>class</code> attribute that is specified for use with the
-<code>xhtml:div</code> model element is not specified for use with the
-corresponding TTML element; in contrast, the details column includes
-"+@begin", which denotes that a <code>begin</code> attribute is added
-that is not specified for use with the <code>xhtml:div</code> model
-element.</p><a id="element-vocab-derivation-table"></a><table class="common"><caption>Table M-1 – Elements</caption><col width="20%" span="1"><col width="17%" span="1"><col width="13%" align="center" span="1"><col width="40%" span="1"><col width="10%" align="center" span="1"><tbody><tr><td><span class="strong">Element</span></td><td><span class="strong">Model</span></td><td><span class="strong">Reference</span></td><td><span class="strong">Details</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="#animation-vocabulary-animate"><code>tt:animate</code></a></td><td><code>svg:animate</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@* except begin, dur, end; +@tts:*, +@xml:lang, +@xml:space</td><td>3,6</td></tr><tr><td><a href="#animation-vocabulary-animation"><code>tt:animation</code></a></td><td><code>tt:layout</code></td><td><a href="#ttml1">[TTML1]</a></td><td>conceptual derivation</td><td>12</td></tr><tr><td><a href="#document-structure-vocabulary-body"><code>tt:body</code></a></td><td><code>xhtml:body</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*; content model
-subsetted to zero or more division (div) children, and supersetted by
-optional metadata and animation children</td><td>1,2</td></tr><tr><td><a href="#content-vocabulary-br"><code>tt:br</code></a></td><td><code>xhtml:br</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@title; +@ttm:*, +@tts:*, +@xml:lang, +@xml:space;
-content model supersetted by
-optional metadata and animation children for congruity with other
-content vocabulary</td><td>1,2</td></tr><tr><td><a href="#content-vocabulary-div"><code>tt:div</code></a></td><td><code>xhtml:div</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*, +@xml:space; content model
-subsetted to zero or more paragraph (p) children, and supersetted by
-optional metadata and animation children</td><td>1,2,3</td></tr><tr><td><a href="#document-structure-vocabulary-head"><code>tt:head</code></a></td><td><code>xhtml:head</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@dir, -@lang, -@profile; +@id, +@xml:space; content model changed to
-optional metadata children, followed by optional styling child,
-followed by optional layout child</td><td>1,3</td></tr><tr><td><a href="#layout-vocabulary-layout"><code>tt:layout</code></a></td><td><code>fo:simple-page-master</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-metadata"><code>tt:metadata</code></a></td><td><code>svg:metadata</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@xml:base; +@ttm:*, +@xml:lang, +@xml:space; content model
-subsetted to foreign namespace element content only (no #PCDATA)</td><td>3,5</td></tr><tr><td><a href="#content-vocabulary-p"><code>tt:p</code></a></td><td><code>xhtml:p</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*, +@xml:space; content model
-subsetted to zero or more span children, and supersetted by optional
-metadata and animation children</td><td>1,2,3</td></tr><tr><td><a href="#layout-vocabulary-region"><code>tt:region</code></a></td><td><code>fo:region-*</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#animation-vocabulary-set"><code>tt:set</code></a></td><td><code>svg:set</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@* except begin, dur, end; +@tts:*, +@xml:lang, +@xml:space</td><td>3,6</td></tr><tr><td><a href="#content-vocabulary-span"><code>tt:span</code></a></td><td><code>xhtml:span</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*, +@xml:space; content model
-subsetted to zero or more #PCDATA or break (br) children, and
-supersetted by optional metadata and animation children</td><td>1,2,3</td></tr><tr><td><a href="#styling-vocabulary-style"><code>tt:style</code></a></td><td><em>style specification</em></td><td><a href="#css2">[CSS2]</a></td><td>XML representation of identified set of pairs of style property
-name and value, with optional inclusion of other styles by reference
-to other style elements</td><td>7</td></tr><tr><td><a href="#styling-vocabulary-styling"><code>tt:styling</code></a></td><td><code>xhtml:style</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>XML representation of a set of style specifications sets, each
-represented by a style child element</td><td>1,7</td></tr><tr><td><a href="#document-structure-vocabulary-tt"><code>tt:tt</code></a></td><td><code>xhtml:html</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@dir, -@lang; +@id, +@ttp:*, +@xml:space; content model subsetted by
-permitting body and/or head to be optional</td><td>1,8</td></tr><tr><td><a href="#metadata-vocabulary-actor"><code>ttm:actor</code></a></td><td><code>mpeg7:Creator</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-agent"><code>ttm:agent</code></a></td><td><code>mpeg7:Agent</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-copyright"><code>ttm:copyright</code></a></td><td><code>mpeg7:CopyrightString</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-desc"><code>ttm:desc</code></a></td><td><code>svg:desc</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@class, -@style, -@xml:base</td><td>2,5,9</td></tr><tr><td><a href="#metadata-vocabulary-name"><code>ttm:name</code></a></td><td><code>mpeg7:Name</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-title"><code>ttm:title</code></a></td><td><code>svg:title</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@class, -@style, -@xml:base</td><td>2,5,9</td></tr><tr><td><a href="#profile-vocabulary-extension"><code>ttp:extension</code></a></td><td><code>@requiredExtensions</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#profile-vocabulary-extensions"><code>ttp:extensions</code></a></td><td><code>@requiredExtensions</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#profile-vocabulary-feature"><code>ttp:feature</code></a></td><td><code>@requiredFeatures</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#profile-vocabulary-features"><code>ttp:features</code></a></td><td><code>@requiredFeatures</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#profile-vocabulary-profile"><code>ttp:profile</code></a></td><td><code>@baseProfile</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>11</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>Derivation is indicated with respect to the strict DTD defined
-by <a href="#xhtml10">[XHTML 1.0]</a>, §A.1.</p></li><li><p>The <code>class</code> attribute is effectively replaced by the
-<code>style</code>
-attribute, which, instead of specifying an inline style,
-refers indirectly to one or more <a href="#styling-vocabulary-style"><code>style</code></a>
-elements that define a set of style specification sets.</p></li><li><p>The <code>xml:lang</code> and <code>xml:space</code> attributes are defined for all element
-types in order to support their inheritance semantics to operate in
-the context of foreign namespace elements.</p></li><li><p>Derivation is conceptual (notional) only.</p></li><li><p>The <code>xml:base</code> attribute is not used since there are no external
-references from core vocabulary.</p></li><li><p>The <code>attributeName</code> and <code>to</code> attributes of
-<code>svg:set</code> are replaced by the
-direct expression of the target attribute name and value by use of a
-<code>tts:*</code> attribute.</p></li><li><p>CSS style specification syntax is mapped to XML by use of
-attributes defined in the TT Style Namespace.</p></li><li><p>The <code>xml:id</code> attribute is defined for use on all element types.</p></li><li><p>The <code>style</code> attribute is supported only on
-<a href="#terms-content-element">content element</a>.</p></li><li><p>Derived from the use of <code>@requiredExtensions</code>
-and <code>@requiredFeatures</code> on the <code>svg:svg</code> element,
-but extended to support distinct specification of optionality.</p></li><li><p>Derived from the use of <code>@baseProfile</code>
-and <code>@version</code> on the <code>svg:svg</code> element.</p></li><li><p>Conceptually derived from existing <code>tt:layout</code> element,
-which is a generic container for layout specifications, but for use
-in defining animation specifications that apply to targeted elements.</p></li></ol></div></div><div class="div2">
-<h3><a id="d3e38099"></a>M.2 Attribute Derivation</h3><p>The first column of <a href="#attribute-vocab-derivation-table"><b>Table M-2 – Attributes</b></a>
-specifies a TTML attribute vocabulary item; the second column specifies the
-syntactic and/or semantic model on which the vocabulary item is based;
-the third column specifies the reference that defines
-the model (if a model is indicated);
-the fourth column specifies details about the derivation; the last
-column refers to additional notes describing the nature of the
-derivation.</p><p>In the fourth column, which describes details of derivation, a
-notation is use to indicate the addition or removal of an attribute
-value.  For example, in the derivation of the <code>timeContainer</code>
-attribute,
-the details column includes "-excl", which denotes that the
-<code>excl</code> value that is specified for use with the
-<code>timeContainer</code> model attribute is not specified for use with the
-corresponding TTML attribute; similarly, an "+<em>value</em>"
-in the details column indicates that the attribute's values have been
-extended to include <em>value</em>.</p><p>Only those attributes that are specified for use on more than one TTML
-element type are listed below. Those per-element namespace attributes
-that are uniquely defined for a specific TTML element type are not
-listed below, but are considered to be part of the specific element
-type's derivation described in <a href="#element-vocab-derivation-table"><b>Table M-1 – Elements</b></a>
-above.</p><a id="attribute-vocab-derivation-table"></a><table class="common"><caption>Table M-2 – Attributes</caption><col width="20%" span="1"><col width="17%" span="1"><col width="13%" align="center" span="1"><col width="40%" span="1"><col width="10%" align="center" span="1"><tbody><tr><td><span class="strong">Attribute</span></td><td><span class="strong">Model</span></td><td><span class="strong">Reference</span></td><td><span class="strong">Details</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="#timing-attribute-begin"><code>begin</code></a></td><td><code>begin</code></td><td><a href="#smil3">[SMIL 3.0]</a></td><td>see notes</td><td>2,3,4</td></tr><tr><td><a href="#timing-attribute-dur"><code>dur</code></a></td><td><code>dur</code></td><td><a href="#smil3">[SMIL 3.0]</a></td><td>see notes</td><td>2,3,4</td></tr><tr><td><a href="#timing-attribute-end"><code>end</code></a></td><td><code>end</code></td><td><a href="#smil3">[SMIL 3.0]</a></td><td>see notes</td><td>2,3,4</td></tr><tr><td><a href="#layout-attribute-region"><code>region</code></a></td><td><code>master-reference</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>conceptual derivation</td><td></td></tr><tr><td><a href="#style-attribute-style"><code>style</code></a></td><td><code>class</code></td><td><a href="#css2">[CSS2]</a></td><td>dereferences style specification(s) directly</td><td></td></tr><tr><td><a href="#timing-attribute-timeContainer"><code>timeContainer</code></a></td><td><code>timeContainer</code></td><td><a href="#smil3">[SMIL 3.0]</a></td><td>
--<code>excl</code>,
--<code>none</code>;
-no default attribute value
-</td><td>5</td></tr><tr><td><a href="#metadata-attribute-agent"><code>ttm:agent</code></a></td><td><em>none</em></td><td></td><td>used to attribute agent of content</td><td></td></tr><tr><td><a href="#metadata-attribute-role"><code>ttm:role</code></a></td><td><em>none</em></td><td></td><td>used to attribute role of content</td><td></td></tr><tr><td><a href="#parameter-attribute-cellResolution"><code>ttp:cellResolution</code></a></td><td><em>none</em></td><td></td><td>expresses uniform grid resolution for cell based coordinates</td><td></td></tr><tr><td><a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a></td><td><em>none</em></td><td></td><td>determines how to interpret time expressions</td><td></td></tr><tr><td><a href="#parameter-attribute-frameRate"><code>ttp:frameRate</code></a></td><td><em>none</em></td><td></td><td>expresses integral frame rate</td><td></td></tr><tr><td><a href="#parameter-attribute-frameRateMultiplier"><code>ttp:frameRateMultiplier</code></a></td><td><em>none</em></td><td></td><td>used to express non-integral, rational frame rates</td><td></td></tr><tr><td><a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a></td><td><em>none</em></td><td></td><td>expresses marker continuity semantics</td><td></td></tr><tr><td><a href="#parameter-attribute-pixelAspectRatio"><code>ttp:pixelAspectRatio</code></a></td><td><em>none</em></td><td></td><td>expresses pixel aspect ratio of related media</td><td></td></tr><tr><td><a href="#profile-attribute-profile"><code>ttp:profile</code></a></td><td><em>none</em></td><td></td><td>expresses profile of TTML used by a <a href="#terms-document-instance">document instance</a></td><td></td></tr><tr><td><a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a></td><td><em>none</em></td><td></td><td>expresses frame counting (drop) modes</td><td></td></tr><tr><td><a href="#parameter-attribute-subFrameRate"><code>ttp:subFrameRate</code></a></td><td><em>none</em></td><td></td><td>expresses sub-frame rate</td><td></td></tr><tr><td><a href="#parameter-attribute-tickRate"><code>ttp:tickRate</code></a></td><td><em>none</em></td><td></td><td>used to interpret tick based time expressions</td><td></td></tr><tr><td><a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a></td><td><em>none</em></td><td></td><td>used to interpret semantics of time expressions</td><td></td></tr><tr><td><a href="#parameter-attribute-version"><code>ttp:version</code></a></td><td><code>version</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>used only integer values</td><td></td></tr><tr><td><a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a></td><td><code>background-color</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1,6</td></tr><tr><td><a href="#style-attribute-border"><code>tts:border</code></a></td><td><code>border</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1,6</td></tr><tr><td><a href="#style-attribute-color"><code>tts:color</code></a></td><td><code>color</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>6</td></tr><tr><td><a href="#style-attribute-direction"><code>tts:direction</code></a></td><td><code>direction</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td></td></tr><tr><td><a href="#style-attribute-display"><code>tts:display</code></a></td><td><code>display</code></td><td><a href="#css2">[CSS2]</a></td><td>only <code>auto</code>, <code>none</code></td><td></td></tr><tr><td><a href="#style-attribute-displayAlign"><code>tts:displayAlign</code></a></td><td><code>display-align</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-extent"><code>tts:extent</code></a></td><td><code>width</code>, <code>height</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>shorthand property</td><td></td></tr><tr><td><a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a></td><td><code>font-family</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code>, extends generic family names</td><td>1</td></tr><tr><td><a href="#style-attribute-fontSize"><code>tts:fontSize</code></a></td><td><code>font-size</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1,7</td></tr><tr><td><a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a></td><td><code>font-style</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code>, -<code>backslant</code></td><td>1</td></tr><tr><td><a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a></td><td><code>font-weight</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code>, -<code>bolder</code>, -<code>lighter</code>, -<code>&lt;number&gt;</code></td><td>1</td></tr><tr><td><a href="#style-attribute-lineHeight"><code>tts:lineHeight</code></a></td><td><code>line-height</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code>, -<code>&lt;number&gt;</code>, -<code>&lt;space&gt;</code></td><td>1</td></tr><tr><td><a href="#style-attribute-opacity"><code>tts:opacity</code></a></td><td><code>opacity</code></td><td><a href="#css3-color">[CSS3 Color]</a></td><td>-<code>inherit</code></td><td></td></tr><tr><td><a href="#style-attribute-origin"><code>tts:origin</code></a></td><td><code>top</code>, <code>left</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>shorthand property</td><td></td></tr><tr><td><a href="#style-attribute-overflow"><code>tts:overflow</code></a></td><td><code>overflow</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code>, -<code>auto</code>, -<code>error-if-overflow</code></td><td></td></tr><tr><td><a href="#style-attribute-padding"><code>tts:padding</code></a></td><td><code>padding</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>8</td></tr><tr><td><a href="#style-attribute-showBackground"><code>tts:showBackground</code></a></td><td><code>showBackground</code></td><td><a href="#smil3">[SMIL 3.0]</a></td><td>-<code>inherit</code></td><td></td></tr><tr><td><a href="#style-attribute-textAlign"><code>tts:textAlign</code></a></td><td><code>text-align</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a></td><td><code>text-decoration</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1,9,12</td></tr><tr><td><a href="#style-attribute-textOrientation"><code>tts:textOrientation</code></a></td><td><code>text-orientation</code></td><td><a href="#css3-wm">[CSS Writing Modes]</a></td><td>
--<code>inherit</code>,
--<code>sideways-left</code>,
--<code>sideways-right</code>,
--<code>use-glyph-orientation</code>
-</td><td>1</td></tr><tr><td><a href="#style-attribute-textOutline"><code>tts:textOutline</code></a></td><td><code>text-shadow</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>10,12</td></tr><tr><td><a href="#style-attribute-unicodeBidi"><code>tts:unicodeBidi</code></a></td><td><code>unicode-bidi</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-visibility"><code>tts:visibility</code></a></td><td><code>visibility</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code>, -<code>collapse</code></td><td></td></tr><tr><td><a href="#style-attribute-wrapOption"><code>tts:wrapOption</code></a></td><td><code>wrap-option</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-writingMode"><code>tts:writingMode</code></a></td><td><code>writing-mode</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>
--<code>inherit</code>,
--<code>bt-lr</code>,
--<code>bt-rl</code>,
--<code>lr-bt</code>,
--<code>rl-bt</code>,
--<code>lr-alternating-rl-bt</code>,
--<code>lr-alternating-rl-tb</code>,
--<code>lr-inverting-rl-bt</code>,
--<code>lr-inverting-rl-tb</code>,
--<code>tb-lr-in-lr-pairs</code>
-</td><td>1</td></tr><tr><td><a href="#style-attribute-zIndex"><code>tts:zIndex</code></a></td><td><code>z-index</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>-<code>inherit</code></td><td>1</td></tr><tr><td><a href="#content-attribute-xml-id"><code>xml:id</code></a></td><td><code>xml:id</code></td><td><a href="#xmlid">[XML ID]</a></td><td>complies with model</td><td></td></tr><tr><td><a href="#content-attribute-xml-lang"><code>xml:lang</code></a></td><td><code>xml:lang</code></td><td><a href="#xml10">[XML 1.0]</a></td><td>complies with model</td><td></td></tr><tr><td><a href="#content-attribute-xml-space"><code>xml:space</code></a></td><td><code>xml:space</code></td><td><a href="#xml10">[XML 1.0]</a></td><td>see notes</td><td>11</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>Attribute name and/or value(s) are normalized to use
-<em>lowerCamelCase</em> naming convention.</p></li><li><p>Restricted to expressing a clock value that denotes one of the
-following in accordance to whether the parameter expressed by the
-<code>ttp:timeBase</code> attribute is <code>media</code>, <code>smpte</code>,
-or <code>clock</code>, respectively:
-(1) an offset from an implicit syncbase that is linked to a media time
-line, (2) an event time
-that represents the occurrence of an implicit media marker, or (3) a wall-clock
-time.</p></li><li><p>Syntactically subsets and supersets the <a href="#smil3">[SMIL 3.0]</a>&nbsp;<code>Clock-value</code> syntax as follows:
-(1) requires non-negative <code>Full-clock-value</code> or
-<code>Timecount-value</code>;
-(2) if <code>Full-clock-value</code>
-then <em>hours</em> must be two or more digits;
-(3) if <code>Timecount-value</code>, then <em>metric</em> must be
-specified;
-(4) uses <code>m</code> as alias for <code>min</code> metric to denote
-minutes;
-(5) adds <code>f</code> and <code>t</code> metrics denoting frames and
-ticks, respectively;
-(6) adds alternative expression of optional <code>Fraction</code> in
-<code>Full-clock-value</code> by specifying frame count or frame
-count with subframe count.
-</p></li><li><p>
-Interpretation of time expression is further constrained by
-parameters expressed by
-<code>ttp:clockMode</code>,
-<code>ttp:dropMode</code>,
-<code>ttp:frameRate</code>,
-<code>ttp:frameRateMultiplier</code>,
-<code>ttp:markerMode</code>,
-<code>ttp:subFrameRate</code>,
-<code>ttp:tickRate</code>, and
-<code>ttp:timeBase</code> attributes.</p></li><li><p>Uses subset of named colors from model to which two aliases are
-added as follows: <code>magenta</code> as <code>fuchsia</code>, and <code>cyan</code>
-as <code>aqua</code>.</p></li><li><p>If not specified, then parallel (par) container semantics apply to
-the element types specified by <a href="#timing-attribute-timeContainer"><b>12.2.4 timeContainer</b></a>.</p></li><li><p>Restricts size to length specification which can be a percentage;
-adds optional second length (or percentage) for
-specifying separate horizontal and vertical scaling of glyph's EM
-square.</p></li><li><p>Expressed in terms of writing mode relative padding properties
-rather than absolute padding properties.</p></li><li><p>Excludes <code>blink</code> and <code>no-blink</code> values.</p></li><li><p>Uses only one length specification instead of two, where one length
-defines distance of outline effect from nominal edge of glyph contour
-outline perpendicular to point of glyph contour. Percentage lengths
-are also added to express outline effect in relative to font size.
-Outline effects are intended to be drawn both outside of outer closed
-contours and inside of inner closed contours.</p></li><li><p>On root element, default attribute value specified as
-<code>default</code>, which is defined in terms of whitespace
-normalization. Semantics of preservation and default normalization are
-defined in terms of presentation semantics by <a href="#content-attribute-xml-space"><b>8.2.9 xml:space</b></a>.</p></li><li><p>Defined to be inheritable.</p></li></ol></div></div></div><div class="div1">
-<h2><a id="qa"></a>N QA Framework Compliance (Non-Normative)</h2><p>This appendix specifies the compliance of this specification with the
-requirements and guidelines defined by <a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/">QA
-Framework Specifications Guidelines</a>&nbsp;<a href="#qaf-sg">[QAF SG]</a>.</p><div class="div2">
-<h3><a id="d3e39092"></a>N.1 Requirements</h3><a id="qa-framework-requirements-table"></a><table class="common"><caption>Table N-1 – QA Framework Requirements Checklist</caption><col width="76%" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><tbody><tr><td><span class="strong">Requirement</span></td><td><span class="strong">YES</span></td><td><span class="strong">NO</span></td><td><span class="strong">N/A</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#include-conformance-clause-principle">Requirement 01: Include a conformance
-clause</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-scope-principle">Requirement 02: Define the scope.</a></td><td><a href="#intro">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#implement-principle">Requirement 03: Identify who or what will implement the specification.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ref-norm-principle">Requirement 04: Make a list of normative references.</a></td><td><a href="#references">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-terms-principle">Requirement 05: Define the terms used in the normative parts of the specification.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conf-label-principle">Requirement 06: Create conformance labels for each part of the conformance model.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#consistent-style-principle">Requirement 07: Use a consistent style for conformance requirements and explain how to distinguish them.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#req-opt-conf-principle">Requirement 08: Indicate which conformance requirements are mandatory, which are recommended, and which are optional.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdivide-mandatory-principle">Requirement 09: If the technology is subdivided, then indicate which subdivisions are mandatory for conformance.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdiv-constraints-principle">Requirement 10: If the technology is subdivided, then address subdivision constraints.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#likehood-extension-principle">Requirement 11: Address Extensibility.</a></td><td><a href="#doctypes">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#deprecated-feature-principle">Requirement 12: Identify deprecated features.</a></td><td></td><td></td><td>N/A</td><td>1</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#degree-support-principle">Requirement 13: Define how each class of product handles each deprecated feature.</a></td><td></td><td></td><td>N/A</td><td>1</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>No feature is deprecated by this version of this specification.</p></li></ol></div></div><div class="div2">
-<h3><a id="d3e39256"></a>N.2 Guidelines</h3><a id="qa-framework-guidelines-table"></a><table class="common"><caption>Table N-2 – QA Framework Guidelines Checklist</caption><col width="76%" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><tbody><tr><td><span class="strong">Guideline</span></td><td><span class="strong">YES</span></td><td><span class="strong">NO</span></td><td><span class="strong">N/A</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conformance-model-gp">Good Practice 01: Define the specification's conformance model in the conformance clause.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#norm-informative-gp">Good Practice 02: Specify in the conformance clause how to distinguish normative from informative content.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conformance-claim-gp">Good Practice 03: Provide the wording for conformance claims.</a></td><td><a href="#claims">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ics-gp">Good Practice 04: Provide an Implementation Conformance Statement Pro Forma.</a></td><td></td><td>NO</td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ics-claim-gp">Good Practice 05: Require an Implementation Conformance Statement as part of valid conformance claims.</a></td><td><a href="#claims">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#use-example-gp">Good Practice 06: Provide examples, use cases, and graphics.</a></td><td><a href="#example">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#write-sample-gp">Good Practice 07: Write sample code or tests.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ref-define-practice">Good Practice 08: When imposing requirements by normative references, address conformance dependencies.</a></td><td><a href="#references">YES</a></td><td></td><td></td><td>1</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-terms-inline-gp">Good Practice 09: Define unfamiliar terms in-line and consolidate the definitions in a glossary section.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#reuse-terms-gp">Good Practice 10: Use terms already defined without changing their definition.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td>2</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#formal-language-gp">Good Practice 11: Use formal languages when possible.</a></td><td><a href="#schemas">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#write-assertion-gp">Good Practice 12: Write Test Assertions.</a></td><td></td><td>NO</td><td></td><td>3</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdivide-foster-gp">Good Practice 13: Create subdivisions of the technology when warranted.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#rules-profiles-gp">Good Practice 14: If the technology is profiled, define rules for creating new profiles.</a></td><td><a href="#vocabulary-profiling">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#need-option-gp">Good Practice 15:Use optional features as warranted.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#label-options-gp">Good Practice 16: Clearly identify optional features.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#constraints-gp">Good Practice 17: Indicate any limitations or constraints on optional features.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#extensions-prohibited-gp">Good Practice 18: If extensibility is allowed, define an extension mechanism.</a></td><td><a href="#extension-vocabulary-overview">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#breaking-conformance-gp">Good Practice 19: Warn extension creators to create extensions that do not interfere with conformance.</a></td><td><a href="#extension-vocabulary-overview">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-error-gp">Good Practice 20: Define error-handling for unknown extensions.</a></td><td><a href="#conformance-processor">YES</a></td><td></td><td></td><td>4</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#workaround-gp">Good Practice 21: Explain how to avoid using a deprecated feature.</a></td><td></td><td></td><td>N/A</td><td>5</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#obsolete-gp">Good Practice 22: Identify obsolete features.</a></td><td></td><td></td><td>N/A</td><td>5</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#error-handling-gp">Good Practice 23: Define an error handling mechanism.</a></td><td><a href="#reduced-infoset">YES</a></td><td></td><td></td><td></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>When making normative references to external specifications,
-specific clauses or sections are cited.</p></li><li><p>See also <a href="#derivation"><b>M Vocabulary Derivation</b></a>.</p></li><li><p>Test assertions and test suites will be provided prior to entering
-Proposed Recommendation (PR) phase.</p></li><li><p>See criterion #3 in <a href="#conformance-processor"><b>3.2 Processor Conformance</b></a> and definition of
-TTML <a href="#doctypes">Abstract Document Instance</a>.</p></li><li><p>No feature is deprecated or obsoleted by this version of this specification.</p></li></ol></div></div></div><div class="div1">
-<h2><a id="streaming"></a>O Streaming TTML Content (Non-Normative)</h2><p>TTML Content is designed to support streamability by implementing the
-following properties:</p><ul><li><p>can be progressively encoded (i.e., does not require computing
-subsequent data prior to sending current data);</p></li><li><p>can be progressively decoded (i.e., does not require forward
-references, but uses only reverse references when necessary);</p></li><li><p>does not require dereferencing (and subsequent loading) of any
-resources other than TTML Content (i.e., no embedded URIs);</p></li><li><p>does not support alternative content forms (e.g., different
-language, graphics formats, time bases) in a single document;</p></li><li><p>has timing structure compiled into inline format that makes
-possible a temporal ordering of content that follows temporal
-presentation order;</p></li><li><p>constrains content models to prevent arbitrary nested content
-structures;</p></li></ul><p>One possible means by which TTML Content may be streamed is to
-partition a <a href="#terms-document-instance">document instance</a>'s information set into
-non-overlapping fragments, where one particular fragment, call it the
-<em>root fragment</em>, represents the front matter (head) of the
-<a href="#terms-document-instance">document instance</a> as well as its top level structural elements, and
-other fragments represent content whose time intervals are expected to
-be active in parallel.</p><p>In applications that require arbitrary (random) entry into a
-stream, i.e., the property of being able to start reading data at an
-arbitrary data access unit, the root fragment will be repetitively
-transmitted (inserted) into the stream in order to permit a decoder to
-resynchronize and acquire sufficient structural information in the
-information set in order to interpret subsequent content
-fragments.</p><p>An example of such a fragmentation of a <a href="#terms-document-instance">document instance</a> is
-shown in <a href="#fragment-streaming-graphic"><b>Figure 3 – Fragment Streaming</b></a>.</p><a id="fragment-streaming-graphic"></a><table class="example-images"><caption>Figure 3 – Fragment Streaming</caption><col span="1"><tbody><tr><td><img src="images/streaming.png" alt="Fragment Streaming"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not define a transport buffer model or a decoder
-capabilities model.</p></div></div><div class="div1">
-<h2><a id="common-styling"></a>P Common Caption Style Examples (Non-Normative)</h2><p>This section provides examples of the following common caption styles using TTML Content
-to obtain the desired behavior:</p><ul><li><p>Pop-On Captions</p></li><li><p>Roll-Up Captions</p></li><li><p>Paint-On Captions</p></li></ul><div class="div2">
-<h3><a id="pop-on-example"></a>P.1 Pop-On Caption Example</h3><p>An example of paint-on captions. In this example, two regions are targeted with alternating, paint-on content, where content is timed
-using explicit sequential time containment rules. Each paragraph is non-overlapping in time and appears in the same single row
-of its targeted region.</p><a id="pop-on-example-1-s"></a><table class="example"><caption>Example – Pop-On Captions</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt ttp:cellResolution="60 20" xml:lang="en" xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#parameter" xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1" tts:color="white" tts:origin="10c 4c" tts:extent="40c 1c"/&gt;
-      &lt;region xml:id="r2" tts:color="yellow" tts:origin="10c 8c" tts:extent="40c 1c"/&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;div timeContainer="seq"&gt;
-      &lt;p region="r1" dur="4s"&gt;Lorem ipsum dolor sit&lt;/p
-      &lt;p region="r2" dur="4s"&gt;Amet consectetur adipiscing elit&lt;/p&gt;
-      &lt;p region="r1" dur="6s"&gt;Sed do eiusmod tempor incididunt labore&lt;/p&gt;
-      &lt;p region="r2" dur="4s"&gt;et dolore magna aliqua&lt;/p&gt;
-      &lt;p region="r1" dur="7s"&gt;Ut enim ad minim veniam quis, nostrud&lt;/p&gt;
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table></div><div class="div2">
-<h3><a id="roll-up-example"></a>P.2 Roll-Up Caption Example</h3><p>An example of roll-up captions. Roll-up effects are achieved by using overlapped time intervals, where zero, one, or two paragraphs appear in the region
-at a given time. Each paragraph consumes a single row (line) of the region since no wrapping occurs. Depending on whether a <a href="#terms-presentation-processor">presentation processor</a> supports
-<a href="#semantics-smooth-scrolling-recommendation">smooth scrolling between adjacent synchronic intermediate document instances</a>, the transitions, i.e., moving an
-old paragraph (line) out and a new paragraph (line) in, will be either smooth or discrete.</p><a id="roll-up-example-1-s"></a><table class="example"><caption>Example – Roll-Up Captions</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt ttp:cellResolution="60 20" xml:lang="en" xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#parameter" xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1" tts:color="white" tts:origin="10c 4c" tts:extent="40c 2c"/&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;div region="r1"&gt;
-      &lt;p begin="0s" end="8s"&gt;Lorem ipsum dolor sit&lt;/p
-      &lt;p begin="4s" end="12s"&gt;Amet consectetur adipiscing elit&lt;/p&gt;
-      &lt;p begin="8s" end="18s"&gt;Sed do eiusmod tempor incididunt labore&lt;/p&gt;
-      &lt;p begin="14s" end="25s"&gt;et dolore magna aliqua&lt;/p&gt;
-      &lt;p begin="18s" end="29s"&gt;Ut enim ad minim veniam quis, nostrud&lt;/p&gt;
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table></div><div class="div2">
-<h3><a id="paint-on-example"></a>P.3 Paint-On Caption Example</h3><p>An example of paint-on captions. Paint-on effects are achieved by using timed <code>span</code> elements in order to expose (paint) inline text units, e.g., words,
-over some time interval. Here, five paragraphs have their individual words sequentially timed in order to paint one new word every second. The end of the active duration of
-each inline element coincides with the end of the <code>div</code> element's parallel time container, so that once a word is painted, it remains in the region (on its rendered line) until the <code>div</code> element's active time interval lapses.</p><a id="paint-on-example-1-s"></a><table class="example"><caption>Example – Paint-On Captions</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt ttp:cellResolution="60 20" xml:lang="en" xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#parameter" xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1" tts:color="white" tts:origin="10c 4c" tts:extent="40c 5c"/&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;div begin="0s" end="25s"&gt;
-      &lt;p&gt;
-        &lt;span begin="0s"&gt;Lorem&lt;/span&gt;
-        &lt;span begin="1s"&gt;ipsum&lt;/span&gt;
-        &lt;span begin="2s"&gt;dolor&lt;/span&gt;
-        &lt;span begin="3s"&gt;sit&lt;/span&gt;
-      &lt;/p&gt;
-      &lt;p&gt;
-        &lt;span begin="4s"&gt;Amet&lt;/span&gt;                
-        &lt;span begin="5s"&gt;consectetur&lt;/span&gt;
-        &lt;span begin="6s"&gt;adipiscing&lt;/span&gt;
-        &lt;span begin="7s"&gt;elit&lt;/span&gt;
-      &lt;/p&gt;
-      &lt;p&gt;
-        &lt;span begin="8s"&gt;Sed&lt;/span&gt;
-        &lt;span begin="9s"&gt;do&lt;/span&gt;
-        &lt;span begin="10s"&gt;eiusmod&lt;/span&gt;
-        &lt;span begin="11s"&gt;tempor&lt;/span&gt;
-        &lt;span begin="12s"&gt;incididunt &lt;/span&gt;
-        &lt;span begin="13s"&gt;labore&lt;/span&gt;
-     &lt;/p&gt;
-     &lt;p&gt;
-        &lt;span begin="14s"&gt;et&lt;/span&gt;
-        &lt;span begin="15s"&gt;dolore&lt;/span&gt;
-        &lt;span begin="16s"&gt;magna&lt;/span&gt;
-        &lt;span begin="17s"&gt;aliqua&lt;/span&gt;
-      &lt;/p&gt;
-      &lt;p&gt;
-        &lt;span begin="18s"&gt;Ut&lt;/span&gt;
-        &lt;span begin="19s"&gt;enim&lt;/span&gt;
-        &lt;span begin="20s"&gt;ad&lt;/span&gt;
-        &lt;span begin="21s"&gt;minim&lt;/span&gt;
-        &lt;span begin="22s"&gt;veniam&lt;/span&gt;
-        &lt;span begin="23s"&gt;quis,&lt;/span&gt;
-        &lt;span begin="24s"&gt;nostrud&lt;/span&gt;
-      &lt;/p&gt;
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table></div></div><div class="div1">
-<h2><a id="cea708-mapping"></a>Q CEA708 Mapping Considerations (Non-Normative)</h2><p>This section provides additional information about mapping CEA708
-constructs to TTML.</p><table border="1" class="ednote" summary="Editorial note: CEA708 Mapping"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: CEA708 Mapping</b></td><td align="right" valign="top">2014-03-06</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Refer to ST2052-11 as starting point. Add additional considerations.</td></tr></table></div><div class="div1">
-<h2><a id="acknowledgments"></a>R Acknowledgments (Non-Normative)</h2><p>The editor acknowledges the current and former members of the Timed Text Working
-Group, the members of other W3C Working Groups, and industry experts
-in other forums who have contributed directly or indirectly to the
-process or content of this document as follows:</p><p>Glenn Adams,
-Thomas Bause-Mason,
-John Birch,
-Kees Blom,
-Bert Bos,
-Brad Botkin,
-Dick Bulterman,
-Frans de Jong,
-Mike Dolan,
-Martin Dürst,
-Donald Evans,
-Geoff Freed,
-Al Gilman,
-Giles Godart-Brown,
-Markus Gylling,
-Markku Hakkinen,
-Sean Hayes,
-Erik Hodge,
-Philipp Hoschka,
-Suzi Hyun,
-Michael Jordan,
-Masahiko Kaneko,
-Courtney Kennedy,
-George Kerscher,
-David Kirby,
-Andrew Kirkpatrick,
-Philippe Le Hégaret,
-Pierre-Anthony Lemieux,
-Chris Lilley,
-Jason Livingston,
-Monica Martin,
-Matthew May,
-Nigel Megitt,
-Thierry Michel,
-Frank Olivier,
-Soohong Daniel Park,
-Silvia Pfeiffer,
-Rohit Puri,
-Brian Raymor,
-David Ronca,
-Patrick Schmitz,
-David Singer,
-Craig Smithpeters,
-Andreas Tai,
-and Mohamed Zergaoui.
-</p><p>The editor wishes to especially acknowledge the following contributions
-by current and past members: Mike Dolan (SMPTE time codes, streaming; SMPTE liaison), David
-Kirby (introductory example document; SMPTE time codes, descriptive metadata; EBU/AAF liaison), Geoff Freed (styling
-and example images of style properties), Sean Hayes (advanced profile
-concepts, including applicative timing, HTML/CSS mapping proposal), Erik Hodge (timing),
-Thierry Michel (metadata), and Dave Singer (animation, scrolling).</p><p>The editor also wishes to acknowledge the support of the following current and past sponsors of his work
-on this specification: Cox Communications, Netflix, Microsoft, and Samsung Electronics.</p><p>The Working Group dedicates this specification to our colleague David Kirby.</p></div></div></body></html>
\ No newline at end of file
--- a/ttml2/spec/ttml2.html	Mon Feb 16 21:07:13 2015 -0800
+++ b/ttml2/spec/ttml2.html	Wed Feb 18 17:23:08 2015 -0700
@@ -85,8 +85,8 @@
 .optattr { font-style: italic }
 </style><link rel="stylesheet" type="text/css" href="https://www.w3.org/StyleSheets/TR/W3C-WD.css"></head><body><div class="head"><p><a href="http://www.w3.org/"><img src="http://www.w3.org/Icons/w3c_home" alt="W3C" height="48" width="72"></a></p>
 <h1><a id="title"></a>Timed Text Markup Language 2 (TTML2)</h1>
-<h2><a id="w3c-doctype"></a>W3C First Public Working Draft 10 February 2015</h2><dl><dt>This version:</dt><dd>
-<a href="http://www.w3.org/TR/2015/WD-ttml2-20150210/">http://www.w3.org/TR/2015/WD-ttml2-20150210/</a>
+<h2><a id="w3c-doctype"></a>W3C First Public Working Draft 12 February 2015</h2><dl><dt>This version:</dt><dd>
+<a href="http://www.w3.org/TR/2015/WD-ttml2-20150212/">http://www.w3.org/TR/2015/WD-ttml2-20150212/</a>
 </dd><dt>Latest version:</dt><dd><a href="http://www.w3.org/TR/ttml2/">http://www.w3.org/TR/ttml2/</a></dd><dt>Latest recommendation:</dt><dd><a href="http://www.w3.org/TR/ttml1/">http://www.w3.org/TR/ttml1/</a></dd><dt>Previous version:</dt><dd>
 None
 </dd><dt>Editor:</dt><dd>Glenn Adams, Skynav, Inc.</dd><dt>Contributing Authors:</dt><dd>Mike Dolan, Invited Expert</dd><dd>Sean Hayes, Microsoft</dd><dd>Frans de Jong, European Broadcasting Union</dd><dd>Pierre-Anthony Lemieux, MovieLabs</dd><dd>Nigel Megitt, British Broadcasting Corporation</dd><dd>Dave Singer, Apple Computer</dd><dd>Jerry Smith, Microsoft</dd><dd>Andreas Tai, Invited Expert</dd></dl><p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a>&nbsp;©&nbsp;2015&nbsp;<a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>, <a href="http://ev.buaa.edu.cn/">Beihang</a>). W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p></div><hr><div>
@@ -100,7 +100,7 @@
 subtitling and captioning functions.</p><p>In addition to being used for interchange among legacy distribution content
 formats, TTML Content may be used directly as a distribution format,
 for example, providing a standard content format to reference from a <code>&lt;track&gt;</code>
-element in an HTML5 document, or a <code>&lt;text&gt;</code> or 
+element in an HTML5 document, or a <code>&lt;text&gt;</code> or
 <code>&lt;textstream&gt;</code> media element in a <a href="#smil3">[SMIL 3.0]</a> document.</p></div><div>
 <h2><a id="status"></a>Status of this Document</h2><p><em>This section describes the status of this document at the
 time of its publication. Other documents may supersede this document.
@@ -570,7 +570,7 @@
 satisfied.</p><p>In addition to being used for interchange among legacy distribution content
 formats, TTML Content may be used directly as a distribution format, providing, for
 example, a standard content format to reference from a <code>&lt;track&gt;</code>
-element in an HTML5 document, or a <code>&lt;text&gt;</code> or 
+element in an HTML5 document, or a <code>&lt;text&gt;</code> or
 <code>&lt;textstream&gt;</code> media element in a <a href="#smil3">[SMIL 3.0]</a> document. Certain properties of TTML support
 streamability of content, as described in <a href="#streaming"><b>O Streaming TTML Content</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>While TTML is not expressly designed for direct (embedded) integration into an
 HTML or a SMIL document instance, such integration is not precluded.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>In some contexts of use, it may be appropriate to employ
@@ -628,7 +628,7 @@
   &lt;!-- alternative using yellow text but otherwise the same as style s1 --&gt;
   &lt;style xml:id="s2" style="s1" tts:color="yellow"/&gt;
   &lt;!-- a style based on s1 but justified to the right --&gt;
-  &lt;style xml:id="s1Right" style="s1" tts:textAlign="end" /&gt;     
+  &lt;style xml:id="s1Right" style="s1" tts:textAlign="end" /&gt;
   &lt;!-- a style based on s2 but justified to the left --&gt;
   &lt;style xml:id="s2Left" style="s2" tts:textAlign="start" /&gt;
 &lt;/styling&gt;
@@ -652,7 +652,7 @@
     tts:backgroundColor="black"
     tts:displayAlign="after"
   /&gt;
-&lt;/layout&gt;  
+&lt;/layout&gt;
 </pre></div>
 </td></tr></tbody></table><p>The content of a <a href="#terms-document-instance">document instance</a> is expressed in its
 body, which is organized in terms of block and inline text elements.
@@ -705,7 +705,7 @@
     &lt;p xml:id="subtitle9b" begin="53.5s" end="58.7s" style="s2"&gt;
       How truly delightful!
     &lt;/p&gt;
-  &lt;/div&gt;    
+  &lt;/div&gt;
 &lt;/body&gt;
 </pre></div>
 </td></tr></tbody></table><p>The first subtitle <a href="#ttml-example-subtitle-1"><b>Subtitle 1 – Time Interval [0.76, 3.45)</b></a> is
@@ -767,7 +767,7 @@
 purpose of being presented (rendered). Such an <a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element
 may specify the audio data inline by using a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element within
 a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element child, or it may reference another
-<a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element specified in a 
+<a href="#embedded-content-vocabulary-audio"><code>audio</code></a> element specified in a
 <a href="#terms-audio-defining-context">audio defining context</a>, or it may do both.</p></dd><dt class="label"><a id="terms-audio-resource"></a>[audio resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> that contains coded or unencoded audio samples.</p></dd><dt class="label"><a id="terms-authoring-viewport"></a>[authoring viewport]</dt><dd><p>A <a href="#terms-viewport">viewport</a> employed at authoring (content encoding) time.</p></dd><dt class="label"><a id="terms-baseline-profile"></a>[baseline profile]</dt><dd><p>A <a href="#terms-profile">profile</a> referenced by the <code>use</code> attribute of a <code>ttp:profile</code> element,
 which serves as a baseline (initial) set of specifications with which to populate the referencing profile.</p></dd><dt class="label"><a id="terms-block-display"></a>[block display]</dt><dd><p>Block display is a set of layout semantics that may be applied to a <a href="#terms-content-element">content element</a> in
 certain contexts, wherein child areas are composed sequentially in the block progression direction. In <a href="#css2">[CSS2]</a>,
@@ -787,7 +787,7 @@
 purpose of semantic binding (association). Such a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element
 may specify the data inline by using a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element within
 a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element child, or it may reference another
-<a href="#embedded-content-vocabulary-data"><code>data</code></a> element specified in a 
+<a href="#embedded-content-vocabulary-data"><code>data</code></a> element specified in a
 <a href="#terms-data-defining-context">data defining context</a>, or it may do both. No presentation (rendering)
 semantics are implied by the mere presence of a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element in this (or any) context.</p></dd><dt class="label"><a id="terms-data-binding-context-for-metadata"></a>[data binding context for metadata]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element the parent of which is a
 <a href="#metadata-vocabulary-metadata"><code>metadata</code></a> element.</p></dd><dt class="label"><a id="terms-data-binding-context-for-source"></a>[data binding context for source]</dt><dd><p>A <a href="#embedded-content-vocabulary-data"><code>data</code></a> element the parent of which is a
@@ -857,7 +857,7 @@
 purpose of being presented (rendered). Such an <a href="#embedded-content-vocabulary-image"><code>image</code></a> element
 may specify the image data inline by using a <a href="#embedded-content-vocabulary-data"><code>data</code></a> element within
 a <a href="#embedded-content-vocabulary-source"><code>source</code></a> element child, or it may reference another
-<a href="#embedded-content-vocabulary-image"><code>image</code></a> element specified in a 
+<a href="#embedded-content-vocabulary-image"><code>image</code></a> element specified in a
 <a href="#terms-image-defining-context">image defining context</a>, or it may do both.</p></dd><dt class="label"><a id="terms-image-resource"></a>[image resource]</dt><dd><p>A <a href="#terms-data-resource">data resource</a> that contains a raster image.</p></dd><dt class="label"><a id="terms-implied-inline-region"></a>[implied inline region]</dt><dd><p>An anonymous (unidentified) <a href="#terms-inline-region">inline region</a> that is implied in the context of a block level
 <a href="#terms-content-element">content element</a>
 due the presence of a <a href="#style-attribute-extent"><code>tts:extent</code></a> or <a href="#style-attribute-origin"><code>tts:origin</code></a>
@@ -893,11 +893,11 @@
 an <a href="#terms-intermediate-synchronic-document">intermediate synchronic document</a>.</p></dd><dt class="label"><a id="terms-nested-profile"></a>[nested profile]</dt><dd><p>A constituent <a href="#terms-profile">profile</a> of a <a href="#terms-nesting-profile">nesting profile</a>, i.e., one of the
 descendant <code>ttp:profile</code> element(s) of a higher level (ancestor) <code>ttp:profile</code> element. A given <code>ttp:profile</code> may serve
 as both a <a href="#terms-nested-profile">nested profile</a> and a <a href="#terms-nesting-profile">nesting profile</a>.</p></dd><dt class="label"><a id="terms-nesting-profile"></a>[nesting profile]</dt><dd><p>A <a href="#terms-profile">profile</a> defined by making reference to one or more child <code>ttp:profile</code> element(s), wherein a
-profile combination method determines how profile specifications from the multiple child <code>ttp:profile</code> element(s) are combined.</p></dd><dt class="label"><a id="terms-nested-embedded-source"></a>[nested embedded source]</dt><dd><p>A <a href="#embedded-content-vocabulary-source"><code>source</code></a> element that specifies a child 
+profile combination method determines how profile specifications from the multiple child <code>ttp:profile</code> element(s) are combined.</p></dd><dt class="label"><a id="terms-nested-embedded-source"></a>[nested embedded source]</dt><dd><p>A <a href="#embedded-content-vocabulary-source"><code>source</code></a> element that specifies a child
 <a href="#embedded-content-vocabulary-data"><code>data</code></a> element which embeds the actual bytes of the
-<a href="#terms-embedded-data-resource">embedded data resource</a>, whether by 
+<a href="#terms-embedded-data-resource">embedded data resource</a>, whether by
 <a href="#terms-simple-data-embedding">simple data embedding</a> or <a href="#terms-chunked-data-embedding">chunked data embedding</a>.</p></dd><dt class="label"><a id="terms-non-content-image"></a>[non-content image]</dt><dd><p>An <a href="#terms-image-resource">image resource</a> that does not contain semantically significant content, e.g., a raster image
-representing a background design, which, if not presented, would not affect the presentation of semntically significant content.</p></dd><dt class="label"><a id="terms-non-nested-embedded-source"></a>[non-nested embedded source]</dt><dd><p>A <a href="#embedded-content-vocabulary-source"><code>source</code></a> element that specifies a child 
+representing a background design, which, if not presented, would not affect the presentation of semntically significant content.</p></dd><dt class="label"><a id="terms-non-nested-embedded-source"></a>[non-nested embedded source]</dt><dd><p>A <a href="#embedded-content-vocabulary-source"><code>source</code></a> element that specifies a child
 <a href="#embedded-content-vocabulary-data"><code>data</code></a> element which does not embed a representation of the actual bytes of the
 <a href="#terms-embedded-data-resource">embedded data resource</a>.</p></dd><dt class="label"><a id="terms-non-nesting-profile"></a>[non-nesting profile]</dt><dd><p>A <a href="#terms-profile">profile</a> defined without making reference to one or more child <code>ttp:profile</code> element(s); that is,
 by including only child <code>ttp:features</code> and <code>ttp:extensions</code> element(s).</p></dd><dt class="label"><a id="terms-out-of-line-animation"></a>[out-of-line animation]</dt><dd><p>An <a href="#animation-vocabulary-animate"><code>animate</code></a> or <a href="#animation-vocabulary-set"><code>set</code></a> element that is defined out-of-line from
@@ -1077,7 +1077,7 @@
 generic processor criteria are
 satisfied:</p><ol class="enumar"><li><p>The processor provides at least one mechanism for notionally
 instantiating a <a href="#terms-reduced-xml-infoset">reduced xml infoset</a>
-representation of a conformant <a href="#terms-document-instance">document instance</a>.</p></li><li><p>If a processor does or can perform validation of a candidate 
+representation of a conformant <a href="#terms-document-instance">document instance</a>.</p></li><li><p>If a processor does or can perform validation of a candidate
 <a href="#terms-document-instance">document instance</a>, then it provides at least one mechanism to
 implicitly or explicitly associate the
 <a href="#terms-reduced-xml-infoset">reduced xml infoset</a> representation
@@ -1313,7 +1313,7 @@
 that corresponds with a set of <a href="#semantics-profile-state-profile-specification"><span class="strong">profile specifications</span></a>,
 additionally recording the constituent
 profiles from which these specifications were obtained (or derived)</p><dl><dt class="label"><a id="semantics-profile-state-combined-profile-specification-set-constituents"></a>constituents</dt><dd><p>ordered list of absolute profile designators, where each designator denotes a constituent profile, i.e.,
-a profile from which this combined profile specification set is composed</p></dd><dt class="label"><a id="semantics-profile-state-combined-profile-specification-set-specifications"></a>specifications</dt><dd><p>ordered list of <a href="#semantics-profile-state-profile-specification"><span class="strong">profile specifications</span></a></p></dd></dl></dd><dt class="label"><a id="semantics-profile-state-empty-profile-specification-set"></a>[empty profile specification set]</dt><dd><p>a <a href="#semantics-profile-state-combined-profile-specification-set"><span class="strong">combined profile specification set</span></a> which 
+a profile from which this combined profile specification set is composed</p></dd><dt class="label"><a id="semantics-profile-state-combined-profile-specification-set-specifications"></a>specifications</dt><dd><p>ordered list of <a href="#semantics-profile-state-profile-specification"><span class="strong">profile specifications</span></a></p></dd></dl></dd><dt class="label"><a id="semantics-profile-state-empty-profile-specification-set"></a>[empty profile specification set]</dt><dd><p>a <a href="#semantics-profile-state-combined-profile-specification-set"><span class="strong">combined profile specification set</span></a> which
 <a href="#semantics-profile-state-combined-profile-specification-set-constituents"><span class="strong">constituents</span></a> and
 <a href="#semantics-profile-state-combined-profile-specification-set-specifications"><span class="strong">specifications</span></a> fields are empty sets</p></dd><dt class="label"><a id="semantics-profile-state-profile"></a>[profile]</dt><dd><p>a <a href="#semantics-profile-state-profile"><span class="strong">profile</span></a> represents the following internal state information
 that corresponds with a <a href="#profile-vocabulary-profile"><code>ttp:profile</code></a> element, whether specified explicitly or implied</p><dl><dt class="label"><a id="semantics-profile-state-profile-designator"></a>designator</dt><dd><p>an absolute profile designator that is associated with (and uniquely labels) this profile</p></dd><dt class="label"><a id="semantics-profile-state-profile-type"></a>type</dt><dd><p><code>content|processor</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-combine"></a>combine</dt><dd><p><code>leastRestrictive|mostRestrictive|replace</code></p></dd><dt class="label"><a id="semantics-profile-state-profile-use"></a>use</dt><dd><p>either <code>null</code> or an absolute profile designator denoting a profile that serves as the baseline profile for this profile</p></dd><dt class="label"><a id="semantics-profile-state-profile-constituents"></a>constituents</dt><dd><p>if profile is a <a href="#terms-nesting-profile">nesting profile</a>, then an ordered list of absolute profile designators, where each designator denotes a
@@ -1356,7 +1356,7 @@
 <a href="#terms-effective-processor-profile">effective processor profile</a> is the combined profile specification set
 produced by combining the combined profile specification sets of the designated profiles, where the <code>mostRestrictive</code>
 processor profile combination method applies;</p></li><li><p>otherwise, if the <code>ttp:processorProfiles</code> attribute is specified using the <code>any(...)</code> function syntax,
-then, for each designated profile, the 
+then, for each designated profile, the
 <a href="#terms-effective-processor-profile">effective processor profile</a> is the combined profile specification set
 of the first profile in the list of designated profiles that is supported by the
 <a href="#terms-content-processor">content processor</a>;</p></li></ol></li><li><p>otherwise, if one or more <a href="#terms-top-level-profile">top-level</a> <a href="#terms-processor-profile">processor profiles</a>
@@ -1663,10 +1663,10 @@
 that used a different naming convention.</p></div></div><div class="div3">
 <h4><a id="extension-vocabulary-overview"></a>5.3.2 Extension Catalog</h4><p>The extension vocabulary catalog is intended for use by future
 profiles of TTML, and is not further defined
-by this version of this specification.</p><p>In addition to standardized extension vocabulary, a conforming 
+by this version of this specification.</p><p>In addition to standardized extension vocabulary, a conforming
 <a href="#terms-document-instance">document instance</a> may contain arbitrary namespace qualified
 elements that reside in any namespace other than those namespaces
-defined for use with this specification. Furthermore, a conforming 
+defined for use with this specification. Furthermore, a conforming
 <a href="#terms-document-instance">document instance</a> may contain arbitrary namespace qualified
 attributes on TTML defined vocabulary where such attributes reside in
 any namespace other than those defined for use with this
@@ -2493,7 +2493,7 @@
 <a href="#semantics-timing"><b>12.4 Timing Semantics</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When operating with <code>smpte</code> time base and
 <code>continuous</code> marker mode, there is an implied time coordinate
 space, the <a href="#terms-synthetic-smpte-document-syncbase">synthetic smpte document syncbase</a>,
-defined by the monotonically increasing (or decreasing) 
+defined by the monotonically increasing (or decreasing)
 <a href="#smpte12m">[SMPTE 12M]</a> time coordinates, while taking into account
 the computed frame rate and drop mode. All time expressions are interpreted
 in relationship to this time coordinate space based upon
@@ -2668,7 +2668,7 @@
 media time base is outside the scope of this specification.</p></div><p>If the time base is designated as <code>smpte</code>,
 then a time expression denotes a <a href="#smpte12m">[SMPTE 12M]</a> time
 coordinate with which the content of a <a href="#terms-document-instance">document instance</a> is to
-be synchronized.  In this case, the value of the <code>ttp:markerMode</code> 
+be synchronized.  In this case, the value of the <code>ttp:markerMode</code>
 and <code>ttp:dropMode</code> parameters apply, as defined by <a href="#parameter-attribute-markerMode"><b>7.2.6 ttp:markerMode</b></a> and <a href="#parameter-attribute-dropMode"><b>7.2.3 ttp:dropMode</b></a>, respectively.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When the time base is designated as <code>smpte</code>,
 every time expression denotes a media marker value akin to that
 defined by <a href="#smil3">[SMIL 3.0]</a>, § 5.4.3, except instead
@@ -2862,7 +2862,7 @@
 with
 a <code>div</code> element in a <a href="#terms-document-instance">document instance</a>
 are available for style inheritance by descendant <a href="#terms-content-element">content elements</a> such as
-<code>div</code>, 
+<code>div</code>,
 <code>p</code>,
 <code>span</code>, and
 <code>br</code>.</p></div><p>If a
@@ -3873,15 +3873,15 @@
 that content.</p><p>Styling attributes are included in TTML to enable authorial intent of presentation
 to be included within a self-contained document. This section describes
 the semantics of style presentation in terms of a standard processing
-model. TTML Processors are not required to present <a href="#terms-document-instance">document instances</a> in any particular way; 
+model. TTML Processors are not required to present <a href="#terms-document-instance">document instances</a> in any particular way;
 but an implementation of this model by a TTML <a href="#terms-presentation-processor">presentation processor</a>
 that provides externally observable results that are consistent with this model is
 likely to lead to a user experience that closely resembles the experience intended by
-the documents' authors.</p><p>The semantics of TTML style presentation are described in terms of the model 
-in <a href="#xsl11">[XSL 1.1]</a>. The effects of the attributes in this section 
+the documents' authors.</p><p>The semantics of TTML style presentation are described in terms of the model
+in <a href="#xsl11">[XSL 1.1]</a>. The effects of the attributes in this section
 are intended to be compatible with the layout and formatting model of XSL; however, Presentation agents
-may use any technology to satisfy the authorial intent of the document. In particular 
-since <a href="#css2">[CSS2]</a> is a subset of this model, a CSS processor may be used 
+may use any technology to satisfy the authorial intent of the document. In particular
+since <a href="#css2">[CSS2]</a> is a subset of this model, a CSS processor may be used
 for the features that the models have in common.</p><p>No normative use of an
 <code>&lt;?xml-stylesheet ... ?&gt;</code> processing instruction is defined
 by this specification.</p><div class="div2">
@@ -3986,7 +3986,7 @@
 adhere to the <code>IDREFS</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
 § 3.3.10, and, furthermore, each IDREF must reference a <code>style</code> element
 which has a <code>styling</code> element as an ancestor.</p><p>If the same IDREF, <em>ID<sub>1</sub></em>, appears more than one time in the value of a <code>style</code>
-attribute, then there should be an intervening IDREF, <em>ID<sub>2</sub></em>, where 
+attribute, then there should be an intervening IDREF, <em>ID<sub>2</sub></em>, where
 <em>ID<sub>2</sub></em> is not equal to <em>ID<sub>1</sub></em>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This constraint is intended to discourage the use of redundant referential styling while still
 allowing the same style to be referenced multiple times in order to potentially override prior
 referenced styles, e.g., when an intervening, distinct style is referenced in the IDREFS list.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>See the specific element type definitions that permit use of the
@@ -4021,7 +4021,7 @@
   How &lt;span <span class="strong">tts:backgroundColor="green"</span>&gt;I wonder&lt;/span&gt; where you're at!
 &lt;/p&gt;
 </pre></div>
-</td></tr></tbody></table><p></p><a id="style-attribute-backgroundColor-example-1-images"></a><table class="example-images"><caption>Example Rendition – Background Color</caption><tbody><tr><td><img src="images/backgroundColor.png" alt="TTML backgroundColor style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+</td></tr></tbody></table><p></p><a id="style-attribute-backgroundColor-example-1-images"></a><table class="example-images"><caption>Example Rendition – Background Color</caption><tbody><tr><td><img src="images/backgroundColor.png" alt="TTML backgroundColor style property"></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.8.2.</p></div></div><div class="div3">
 <h4><a id="style-attribute-backgroundImage"></a>10.2.3 tts:backgroundImage</h4><p>The <code>tts:backgroundImage</code> attribute is used to specify a style property that
 designates a background <a href="#terms-non-content-image">non-content image</a> to be rendered as
@@ -4073,7 +4073,7 @@
   &lt;style tts:padding="3px 40px"/&gt;
 &lt;/region&gt;
 </pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Image Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Image Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundImage example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Image Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Image Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundImage example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.8.3.</p></div></div><div class="div3">
 <h4><a id="style-attribute-backgroundPosition"></a>10.2.4 tts:backgroundPosition</h4><p>The <code>tts:backgroundPosition</code> attribute is used to specify a style property that
 defines whether and how a background image is positioned in a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any element type
@@ -4101,7 +4101,7 @@
   &lt;style <span class="strong">tts:backgroundPosition="center"</span>/&gt;
 &lt;/region&gt;
 </pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Position Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Position Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundPosition example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Position Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Position Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundPosition example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#css2">[CSS2]</a>, § 14.2.</p></div></div><div class="div3">
 <h4><a id="style-attribute-backgroundRepeat"></a>10.2.5 tts:backgroundRepeat</h4><p>The <code>tts:backgroundRepeat</code> attribute is used to specify a style property that
 defines whether and how a background image is repeated (tiled) into a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any element type
@@ -4127,7 +4127,7 @@
   &lt;style <span class="strong">tts:backgroundRepeat="repeatX"</span>/&gt;
 &lt;/region&gt;
 </pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Repeat Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Repeat Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundRepeat example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Background Repeat Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Background Repeat Example Image</b></td><td align="right" valign="top">2014-11-21</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of backgroundRepeat example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.8.4.</p></div></div><div class="div3">
 <h4><a id="style-attribute-border"></a>10.2.6 tts:border</h4><p>The <code>tts:border</code> attribute is used to specify a style property that
 defines the border of a region or an area generated by content flowed into a region.</p><p>This attribute may be specified by any
@@ -4172,7 +4172,7 @@
   How &lt;span <span class="strong">tts:border="8px solid blue"</span>&gt;I wonder&lt;/span&gt; where you're at!
 &lt;/p&gt;
 </pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Border Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Border Example Image</b></td><td align="right" valign="top">2013-08-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of border example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Border Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Border Example Image</b></td><td align="right" valign="top">2013-08-24</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of border example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#xsl11">[XSL 1.1]</a>, § 7.31.3.</p></div></div><div class="div3">
 <h4><a id="style-attribute-bpd"></a>10.2.7 tts:bpd</h4><p>The <code>tts:bpd</code> attribute is used to specify the
 <em>block progression dimension</em>, or, more succinctly, the <em>bpd</em> of an area generated by content flowed into a region.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The term <em>block progression dimension</em> is interpreted in a writing mode relative manner
@@ -4425,7 +4425,7 @@
 </td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>relative to width and height of <a href="#terms-root-container-region">root container region</a></td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>If the value of this attribute consists of two <a href="#style-value-measure">&lt;measure&gt;</a>
 specifications, then they must be interpreted as <em>width</em>
 and <em>height</em>, where the first specification is the
-<em>width</em>, and the second specification is the <em>height</em>.</p><p>The <a href="#style-value-measure">&lt;measure&gt;</a> value(s) used to express extent must be non-negative.</p><p>If applied to a <a href="#terms-region">region</a> other than the <a href="#terms-root-container-region">root container region</a> and 
+<em>width</em>, and the second specification is the <em>height</em>.</p><p>The <a href="#style-value-measure">&lt;measure&gt;</a> value(s) used to express extent must be non-negative.</p><p>If applied to a <a href="#terms-region">region</a> other than the <a href="#terms-root-container-region">root container region</a> and
 the value of this attribute is <code>auto</code>, then the computed value
 of the style property must be considered to be the same as the extent of the <a href="#terms-root-container-region">root container region</a>.</p><table border="1" class="ednote" summary="Editorial note: Semantics of contain and cover"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Semantics of contain and cover</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Define semantics of new <code>contain</code> and <code>cover</code> values. Exclude these values from use with an <code>image</code> element.</td></tr></table><p>The extent of the <a href="#terms-root-container-region">root container region</a> is determined either by a
 <code>tts:extent</code> specified on the <code>tt</code> element, if
@@ -4775,7 +4775,7 @@
 </p></li><li><p>
 Set the computed value of this style property to <em>LH</em>.
 </p></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>If a content author wishes to avoid the possibility of different interpretations of <code>normal</code>, for example, due to differences in
-the set of available fonts, then it is recommended that a 
+the set of available fonts, then it is recommended that a
 <a href="#style-value-length">&lt;length&gt;</a> value expression be used to explicitly specify line height value.</p></div><p>If specified as a <a href="#style-value-length">&lt;length&gt;</a>, then the length must
 be non-negative.</p><p>If a computed value of the property associated with this attribute is not supported,
 then a <a href="#terms-presentation-processor">presentation processor</a> must use the closest supported value.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between
@@ -5069,7 +5069,7 @@
    To simper at a table-cloth!"
 &lt;/p&gt;
 </pre></div>
-</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Position Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Position Example Image</b></td><td align="right" valign="top">2014-11-28</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of position example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+</td></tr></tbody></table><p></p><table border="1" class="ednote" summary="Editorial note: Position Example Image"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Position Example Image</b></td><td align="right" valign="top">2014-11-28</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert image of position example.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 the <code>background-position</code> property defined by <a href="#css3-bb">[CSS Backgrounds and Borders]</a>, § 3.6.</p></div></div><div class="div3">
 <h4><a id="style-attribute-ruby"></a>10.2.30 tts:ruby</h4><p>The <code>tts:ruby</code> attribute is used to specify the application of ruby
 styling.</p><p>This attribute may be specified by any element type that permits use of attributes in the TT Style Namespace; however,
@@ -5378,7 +5378,7 @@
 span.</p><p>If the specified value of this attribute is <code>none</code>, then no combination processing applies.
 If the specified value of this attribute is <code>all</code>, then all affected characters should be combined.
 If the specified value of this attribute is <code>digits</code>, then all affected characters should be combined if they are a sequence of a digits which length is
-equal to or less than a specified count, or two (2) if no count is specified.</p><p>Combination must not cross an element boundary, a bidirectional boundary, or a non-glyph area boundary.</p><p>This attribute has no impact on or interaction with the nominal layout of glyph areas that constitute a Unicode combining character sequence.</p><table border="1" class="ednote" summary="Editorial note: Text Combine Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Combine Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textCombine.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+equal to or less than a specified count, or two (2) if no count is specified.</p><p>Combination must not cross an element boundary, a bidirectional boundary, or a non-glyph area boundary.</p><p>This attribute has no impact on or interaction with the nominal layout of glyph areas that constitute a Unicode combining character sequence.</p><table border="1" class="ednote" summary="Editorial note: Text Combine Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Combine Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textCombine.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#css3-wm">[CSS Writing Modes]</a>, § 9.1.</p></div></div><div class="div3">
 <h4><a id="style-attribute-textDecoration"></a>10.2.37 tts:textDecoration</h4><p>The <code>tts:textDecoration</code> attribute is used to specify a style property that
 defines a text decoration effect to apply to glyph areas or other inline
@@ -5449,7 +5449,7 @@
 If no emphasis color is specified,
 then the emphasis color must be interpreted as if a color of <code>current</code> were specified.
 If no emphasis position is specified,
-then the emphasis position must be interpreted as if a position of <code>auto</code> were specified.</p><table border="1" class="ednote" summary="Editorial note: Text Emphasis Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Emphasis Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textEmphasis.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+then the emphasis position must be interpreted as if a position of <code>auto</code> were specified.</p><table border="1" class="ednote" summary="Editorial note: Text Emphasis Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Emphasis Example</b></td><td align="right" valign="top">2015-01-05</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textEmphasis.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#css3-decoration">[CSS Text Decoration]</a>, § 3.</p></div></div><div class="div3">
 <h4><a id="style-attribute-textOrientation"></a>10.2.39 tts:textOrientation</h4><p>The <code>tts:textOrientation</code> attribute is used to specify a style property that
 defines a text orientation to apply to glyphs that are selected for glyph areas generated
@@ -5550,7 +5550,7 @@
 </td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to this element's font size</td></tr><tr><td><em>Animatable:</em></td><td>discrete, continuous</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
 each character child of a <code>p</code> element is considered to be enclosed in an anonymous
 span.</p><p>If a computed value of the property associated with this attribute is not supported,
-then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>none</code>.</p><table border="1" class="ednote" summary="Editorial note: Text Shadow Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Shadow Example</b></td><td align="right" valign="top">2015-01-08</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textShadow.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon 
+then a <a href="#terms-presentation-processor">presentation processor</a> must use the value <code>none</code>.</p><table border="1" class="ednote" summary="Editorial note: Text Shadow Example"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: Text Shadow Example</b></td><td align="right" valign="top">2015-01-08</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Insert example fragment and image of tts:textShadow.</td></tr></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the style property represented by this attribute are based upon
 that defined by <a href="#css3-decoration">[CSS Text Decoration]</a>, § 4.</p></div></div><div class="div3">
 <h4><a id="style-attribute-unicodeBidi"></a>10.2.42 tts:unicodeBidi</h4><p>The <code>tts:unicodeBidi</code> attribute is used to specify a style property that
 defines a directional embedding or override according to
@@ -5921,7 +5921,7 @@
 <div class="exampleInner"><pre>
 &lt;emphasis-style&gt;
   : none
-  | auto 
+  | auto
   | [ filled | open ] || [ circle | dot | sesame ]
   | <a href="#content-value-quoted-string">&lt;quoted-string&gt;</a>
 </pre></div>
@@ -6065,7 +6065,7 @@
 </pre></div>
 </td></tr></tbody></table><p>If no <em>units</em> component is specified in a &lt;length&gt; expression, then it is to be treated as
 if <code>px</code> (pixels) units were specified.</p><p>The semantics of
-the unit of measure <code>px</code> (pixel) 
+the unit of measure <code>px</code> (pixel)
 are as defined by <a href="#xsl11">[XSL 1.1]</a>, § 5.9.13.</p><div class="issue"><p class="prefix"><a id="issue-179"></a><b>Issue (issue-179):</b></p><p class="prefix"><b>Definition of Pixel</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/179">http://www.w3.org/AudioVideo/TT/tracker/issues/179</a></p><p>Replace unworkable (and unadopted) definition of pixel with an appropriate definition based on units of some viewport coordinate space.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div><p>When specified relative to a font whose size is expressed as a single length
 measure or as two length measures of equal length, the unit of measure <code>em</code> is considered to be
 identical to that defined by <a href="#xsl11">[XSL 1.1]</a>, § 5.9.13;
@@ -6591,7 +6591,7 @@
 separable. Layout matter specifies one or more spaces or areas into
 which content is intended to be presented, while style matter specifies the manner in
 which presentation occurs within the layout.</p><p>In certain cases, a content author may choose to embed (inline) style matter directly
-into layout or content matter. In such cases, an alternative 
+into layout or content matter. In such cases, an alternative
 exists – use of referential styling –
 in which the style
 matter is not embedded (inlined).</p></div><div class="div2">
@@ -6621,7 +6621,7 @@
 in the <a href="#element-vocab-group-block">Block.class</a> element group.
 In the former case, the region is referred to as an <a href="#terms-out-of-line-region">out-of-line region</a>, while in the latter
 case, it is referred to as an <a href="#terms-inline-region">inline region</a>.</p><p>In addition, and in accordance with
-<a href="#semantics-style-inheritance-region"><b>10.4.2.2 Region Style Inheritance</b></a>, 
+<a href="#semantics-style-inheritance-region"><b>10.4.2.2 Region Style Inheritance</b></a>,
 the <code>region</code> element may be used to specify inheritable style properties to be
 inherited by content that is flowed into it.</p><p>The <code>region</code> element accepts as its children zero or more
 elements in the <a href="#element-vocab-group-metadata"><code>Metadata.class</code></a> element group,
@@ -6807,7 +6807,7 @@
 <a href="#styling-vocabulary-styling"><code>styling</code></a> element, if present, and immediately before an
 <a href="#animation-vocabulary-animation"><code>animation</code></a> element, if present, or as the last child of
 the <a href="#document-structure-vocabulary-head"><code>head</code></a> element if neither are present;</p></li><li><p>append <em>R'&nbsp;</em> to the <code>[children]</code> information item property of the
-<a href="#layout-vocabulary-layout"><code>layout</code></a> element child of the 
+<a href="#layout-vocabulary-layout"><code>layout</code></a> element child of the
 <a href="#document-structure-vocabulary-head"><code>head</code></a> element;</p></li><li><p>add a <a href="#layout-attribute-region"><code>region</code></a> attribute with value <em>ID</em> to the <code>[attributes]</code> information
 item property of <em>B</em>;</p></li><li><p>remove <em>R</em> from the <code>[children]</code> information item property of <em>B</em>;</p></li></ol><div class="issue"><p class="prefix"><a id="issue-324"></a><b>Issue (issue-324):</b></p><p class="prefix"><b>Duration Restrictions</b></p><p><b>Source</b>: <a href="http://www.w3.org/AudioVideo/TT/tracker/issues/324">http://www.w3.org/AudioVideo/TT/tracker/issues/324</a></p><p>Handle case where use of <code>dur</code> is not permitted, e.g., when using discontinuous SMPTE time base.</p><p class="prefix"><b>Resolution:</b></p><p>None recorded.</p></div></dd></dl><p>The use of an <em>implied inline region specification</em> and the resulting generated inline region is shown by the following two example documents.</p><a id="semantics-inline-region-input-example-1-implied"></a><table class="example"><caption>Example – Implied Inline Region Specification</caption><tbody><tr><td>
 <div class="exampleInner"><pre>
@@ -6866,7 +6866,7 @@
 duration of a <a href="#terms-document-instance">document instance</a> is divided into a sequence of time coordinates where at
 each time coordinate, some element becomes temporally active or inactive,
 then, at each such time coordinate, a <a href="#terms-document-instance">document instance</a> is mapped from its original, source
-form, <em>DOC<sub>source</sub></em> , 
+form, <em>DOC<sub>source</sub></em> ,
 to an intermediate
 synchronic document form,
 <em>DOC<sub>inter</sub></em> , according to the
@@ -6909,14 +6909,14 @@
 by <a href="#cea608e">[CEA-608-E]</a>, § C.3, and <a href="#ccreq">[CC-DECODER-REQ]</a>.</p></div></div><div class="div4">
 <h5><a id="semantics-region-layout-step-2"></a>11.3.1.4 Synchronic Flow Processing</h5><p>Subsequent to performing a temporal (synchronic) slice and subsequent
 remapping of regionally selected content hierarchy, the resulting intermediate
-synchronic document is subjected to a flow transformation step that produces 
+synchronic document is subjected to a flow transformation step that produces
 a rooted flow object tree represented as an XSL FO document instance as defined by <a href="#xsl11">[XSL 1.1]</a>,
 and semantically extended by TTML specific style properties that have no XSL
 FO counterpart.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this section, the use of XSL FO is intended to be conceptual only, employed
 solely for the purpose of defining the normative presentation semantics of
 TTML. An actual implementation of this algorithm is not required to create or process
 XSL-FO representations. In particular, it is possible to implement these semantics
-using alternative presentation models, such as Cascading Style Sheets (CSS).</p></div><p>Each intermediate synchronic document produced by <a href="#semantics-region-layout-step-1"><b>11.3.1.3 Intermediate Synchronic Document Construction</b></a> is mapped 
+using alternative presentation models, such as Cascading Style Sheets (CSS).</p></div><p>Each intermediate synchronic document produced by <a href="#semantics-region-layout-step-1"><b>11.3.1.3 Intermediate Synchronic Document Construction</b></a> is mapped
 to an XSL FO document instance, <em>F</em>, as follows:</p><ol class="enumar"><li><p>perform the following ordered sub-steps to create anonymous spans:</p><ol class="enumla"><li><p>for each significant text node in a <a href="#terms-content-element">content element</a>,
 synthesize an anonymous span to enclose the text node, substituting
 the new anonymous span for the original text node child in its sibling
@@ -6979,10 +6979,10 @@
 to the relevant formatting object produced by the input TTML <a href="#terms-content-element">content element</a> to
 which the style property applies;</p></li><li><p>optionally, synthesize a unique <code>id</code> attribute on each resulting
 formatting object element that relates that element to the input element that
-resulted in that formatting object element;</p></li></ol><p>For each resulting document instance F, if processing requires presentation on a 
-visual medium, then apply formatting and rendering semantics consistent with that 
-prescribed by <a href="#xsl11">[XSL 1.1]</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In an XSL FO area tree produced by formatting <em>F</em> using 
-an <a href="#xsl11">[XSL 1.1]</a> formatting processor, 
+resulted in that formatting object element;</p></li></ol><p>For each resulting document instance F, if processing requires presentation on a
+visual medium, then apply formatting and rendering semantics consistent with that
+prescribed by <a href="#xsl11">[XSL 1.1]</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In an XSL FO area tree produced by formatting <em>F</em> using
+an <a href="#xsl11">[XSL 1.1]</a> formatting processor,
 the <code>page-viewport-area</code>,
 which is generated by <code>fo:page-sequence</code> element by
 reference to the sole generated <code>fo:simple-page-master</code>
@@ -7093,8 +7093,8 @@
   &lt;/head&gt;
 &lt;/tt&gt;
 </pre></div>
-</td></tr></tbody></table><p>An XSL FO document instance that would yield rendering consistent with TTML, and 
-which may be produced by performing flow processing upon the first intermediate 
+</td></tr></tbody></table><p>An XSL FO document instance that would yield rendering consistent with TTML, and
+which may be produced by performing flow processing upon the first intermediate
 document is illustrated below.</p><a id="region-mapping-example-1-f0"></a><table class="example"><caption>Example – XSL FO Document – [0s,1s)</caption><tbody><tr><td>
 <div class="exampleInner"><pre>&lt;fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"&gt;
   &lt;fo:layout-master-set&gt;
@@ -7874,9 +7874,9 @@
   &lt;/head&gt;
   &lt;body&gt;
     &lt;div&gt;
-      ...  
+      ...
       &lt;p <span class="strong">ttm:agent="bond"</span>&gt;I travel, a sort of licensed troubleshooter.&lt;/p&gt;
-      ...  
+      ...
     &lt;/div&gt;
   &lt;/body&gt;
 &lt;/tt&gt;
@@ -8056,7 +8056,7 @@
   : <a href="#metadata-value-named-item">&lt;named-item&gt;</a>
   | <a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>
 </pre></div>
-</td></tr></tbody></table><p>If an item name expression takes the form of a qualified name (<a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>), 
+</td></tr></tbody></table><p>If an item name expression takes the form of a qualified name (<a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>),
 then the prefix of that qualified name must have been declared in a namespace declaration as specified by <a href="#xmlns10">[XML Namespaces 1.0]</a>.</p><p>All values of &lt;item-name&gt; that do not take the form of qualified name (<a href="http://www.w3.org/TR/xmlschema-2/#QName">xsd:QName</a>)
 are reserved for future standardization by the W3C.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>It is intended that all item names defined by this specification are unqualified (without a prefix), whereas those defined by
 external specifications are qualified (with a prefix).</p></div></div><div class="div3">
@@ -8209,7 +8209,7 @@
   : { XML NameChar }                        // XML 1.1 Production [4a]
 </pre></div><p>All values of <code>feature-designation</code> not defined by this specification are reserved
 for future standardization.</p><p>The following sub-sections define all feature designations, expressed
-as relative URIs (fragment identifiers) with respect to the 
+as relative URIs (fragment identifiers) with respect to the
 TT Feature Namespace base URI.</p><table border="1" class="ednote" summary="Editorial note: #animation subset features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: #animation subset features</b></td><td align="right" valign="top">2013-08-26</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add fine grained subset features of #animation.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: #inline-region features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: #inline-region features</b></td><td align="right" valign="top">2014-03-27</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add feature(s) associated with support for explicit and implied inline regions.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: New style property features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: New style property features</b></td><td align="right" valign="top">2014-10-02</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add features to cover new style properties: border, fontVariantPosition, ruby, rubyAlign, rubyOffset, rubyPosition, textOrientation, etc.</td></tr></table><p></p><table border="1" class="ednote" summary="Editorial note: New embedded content features"><tr class="ednote-r1"><td align="left" valign="top"><b>Editorial note: New embedded content features</b></td><td align="right" valign="top">2014-11-27</td></tr><tr class="ednote-r2"><td colspan="2" align="left" valign="top">Add features to cover new embedded content features: audio, data, font, image, etc.</td></tr></table><div class="div3">
 <h4><a id="feature-animation"></a>E.1.1 #animation</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the <code>#animation</code>
 feature if it recognizes and is capable of transforming the following
@@ -8749,7 +8749,7 @@
 attribute.</p></div><div class="div3">
 <h4><a id="feature-presentation"></a>E.1.70 #presentation</h4><p>A TTML processor supports the
 <code>#presentation</code> feature if it
-(1) satisfies the generic processor criteria defined by 
+(1) satisfies the generic processor criteria defined by
 <a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a>,
 (2) implements support for the region and line layout
 semantics defined by <a href="#semantics-region-layout"><b>11.3.1 Region Layout and Presentation</b></a> and
@@ -8991,7 +8991,7 @@
 presentation semantic support for the same features and syntax
 specified above.</p></div><div class="div3">
 <h4><a id="feature-time-offset-with-ticks"></a>E.1.102 #time-offset-with-ticks</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
-<code>#time-offset-with-ticks</code> feature if it supports the 
+<code>#time-offset-with-ticks</code> feature if it supports the
 <a href="#feature-tickRate"><code>#tickRate</code></a> feature
 and if it recognizes and is capable of
 transforming all values of the <a href="#timing-value-time-expression">&lt;time-expression&gt;</a> that
@@ -9008,7 +9008,7 @@
 same vocabulary enumerated above.</p></div><div class="div3">
 <h4><a id="feature-transformation"></a>E.1.104 #transformation</h4><p>A TTML processor supports the
 <code>#transformation</code> feature if it
-(1) satisfies the generic processor criteria defined by 
+(1) satisfies the generic processor criteria defined by
 <a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a> and
 (2) implements the transformation semantics of the following features:</p><ul><li><p><a href="#content"><code>#content</code></a></p></li><li><p><a href="#feature-core"><code>#core</code></a></p></li><li><p><a href="#feature-profile"><code>#profile</code></a></p></li><li><p><a href="#feature-structure"><code>#structure</code></a></p></li><li><p><a href="#feature-time-offset"><code>#time-offset</code></a></p></li><li><p><a href="#timing"><code>#timing</code></a></p></li></ul></div><div class="div3">
 <h4><a id="feature-unicodeBidi"></a>E.1.105 #unicodeBidi</h4><p>A TTML <a href="#terms-transformation-processor">transformation processor</a> supports the
@@ -9773,7 +9773,7 @@
 timed element exists, then <code>referenceBegin</code> is the SMPTE time that corresponds to the active end of the
 immediate prior sibling timed element;
 <br></p></blockquote>
-</td></tr></tbody></table><p>Given the derived media time base as described above, then 
+</td></tr></tbody></table><p>Given the derived media time base as described above, then
 media time base <span class="strong"><code>M</code></span> is related to the local real time <span class="strong"><code>R</code></span>
 as described in <a href="#time-expression-semantics-media"><b>H.2 Media Time Base</b></a> above.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The begin time of the <a href="#terms-root-temporal-extent">root temporal extent</a> is related to the begin time of a
 <a href="#terms-related-media-object">related media object</a> in accordance with the computed value of the
@@ -9792,7 +9792,7 @@
 <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element as its root document element. When an instance of a
 <a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a> is included in a
 <a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a> instance, then the ISD instance is represented
-by an <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> child element of the root 
+by an <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> child element of the root
 <a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>An ISD instance may contain one or more animate elements that denote continuous animation within the associated interval. Continuously animated styles are sub-divided across
 ISD interval boundaries such that their step-wise concatenation expresses an equivalent continuous animation over any intersecting ISD interval(s).</p></div><p>A TTML <a href="#terms-intermediate-synchronic-document-sequence">Intermediate Synchronic Document Sequence</a> represents a collection
 of temporally non-overlapping <a href="#terms-intermediate-synchronic-document">Intermediate Synchronic Document</a> instances ordered according
@@ -9863,7 +9863,7 @@
 of the source TTML document from which this <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element was derived.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Expressed in the terminology of <a href="#smil3">[SMIL 3.0]</a>, the values of these <code>begin</code> and <code>end</code> attributes
 correspond to the resolved begin and end times of the <em>active duration</em> with respect to the <em>document begin</em>.</p></div><p>An <a href="#content-attribute-xml-lang"><code>xml:lang</code></a> attribute must be specified on the
 <a href="#isd-vocabulary-isd"><code>isd:isd</code></a> element if it is a standalone <a href="#terms-intermediate-synchronic-document">Intermediate
-Synchronic Document</a> document; otherwise, it may be specified, and should be specified if the default language of the 
+Synchronic Document</a> document; otherwise, it may be specified, and should be specified if the default language of the
 <a href="#isd-vocabulary-sequence"><code>isd:isd</code></a> element differs from the default language of its
 parent <a href="#isd-vocabulary-sequence"><code>isd:sequence</code></a> element.
 If its value is empty, it signifies that there is no default language that applies
@@ -9917,7 +9917,7 @@
 set of initial style values that apply to <a href="#layout-vocabulary-region"><code>region</code></a>, then a
 <code>style</code> attribute must be specified which references an <a href="#isd-vocabulary-css"><code>isd:css</code></a> element that specifies the
 region's computed style set.</p><p>The following constraints apply to the <a href="#document-structure-vocabulary-body"><code>body</code></a> element
-and its descendant elements:</p><ul><li><p>no <code>animate</code> attribute is specified;</p></li><li><p>no <code>begin</code> attribute is specified;</p></li><li><p>no <code>dur</code> attribute is specified;</p></li><li><p>no <code>end</code> attribute is specified;</p></li><li><p>no <code>region</code> attribute is specified;</p></li><li><p>no <code>timeContainer</code> attribute is specified;</p></li><li><p>no attribute in the TT Style namespace is specified;</p></li><li><p>no <a href="#animation-vocabulary-set">set</a> element is present;</p></li><li><p>no significant text node, i.e., text node in a #PCDATA context, is not contained in a 
+and its descendant elements:</p><ul><li><p>no <code>animate</code> attribute is specified;</p></li><li><p>no <code>begin</code> attribute is specified;</p></li><li><p>no <code>dur</code> attribute is specified;</p></li><li><p>no <code>end</code> attribute is specified;</p></li><li><p>no <code>region</code> attribute is specified;</p></li><li><p>no <code>timeContainer</code> attribute is specified;</p></li><li><p>no attribute in the TT Style namespace is specified;</p></li><li><p>no <a href="#animation-vocabulary-set">set</a> element is present;</p></li><li><p>no significant text node, i.e., text node in a #PCDATA context, is not contained in a
 <a href="#content-vocabulary-span"><code>span</code></a> element that contains no other child.</p></li></ul><p>In addition, for the <a href="#document-structure-vocabulary-body"><code>body</code></a> element <em>B</em> and
 each of its descendant content elements <em>C</em>, if the computed style set of <em>B</em> or each <em>C</em> is
 not equal to the computed style set of its parent element, then that element, <em>B</em> or <em>C</em>, must specify a <code>style</code>
@@ -9958,12 +9958,12 @@
 </dd><dt class="label"><a id="media-queries"></a>Media Queries</dt><dd>Florian Rivoal,,
 <a href="http://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/"><cite>Media Queries</cite></a>, W3C Recommendation, 19 June 2012. (See
 <a href="http://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/">http://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/</a>.)
-</dd><dt class="label"><a id="mime"></a>MIME</dt><dd>Ned Freed and Nathaniel Borenstein,  
+</dd><dt class="label"><a id="mime"></a>MIME</dt><dd>Ned Freed and Nathaniel Borenstein,
 <a href="http://www.rfc-editor.org/rfc/rfc2045.txt"><cite>Multipurpose Internet
 Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite></a>,
 RFC 2045, November 1996, IETF.(See
 <a href="http://www.rfc-editor.org/rfc/rfc2045.txt">http://www.rfc-editor.org/rfc/rfc2045.txt</a>.)
-</dd><dt class="label"><a id="media-types"></a>MIME Media Types</dt><dd>Ned Freed and Nathaniel Borenstein,  
+</dd><dt class="label"><a id="media-types"></a>MIME Media Types</dt><dd>Ned Freed and Nathaniel Borenstein,
 <a href="http://www.rfc-editor.org/rfc/rfc2046.txt"><cite>Multipurpose Internet
 Mail Extensions (MIME) Part Two: Media Types</cite></a>,
 RFC 2046, November 1996, IETF.(See
@@ -10128,7 +10128,7 @@
 <a href="http://www.w3.org/TR/2013/NOTE-ttml10-sdp-us-20130205/"><cite>TTML Simple Delivery Profile for Closed Captions (US)</cite></a>,
 W3C WG Note, 5 February 2013. (See
 <a href="http://www.w3.org/TR/2013/NOTE-ttml10-sdp-us-20130205/">http://www.w3.org/TR/2013/NOTE-ttml10-sdp-us-20130205/</a>.)
-</dd><dt class="label"><a id="smpte170m"></a>SMPTE 170M</dt><dd>ANSI/SMPTE 170M, 
+</dd><dt class="label"><a id="smpte170m"></a>SMPTE 170M</dt><dd>ANSI/SMPTE 170M,
 <a href="http://www.smpte.org/"><cite>Television – Composite Analog Video
 Signal – NTSC for Studio Applications</cite></a>, SMPTE Standard.
 </dd><dt class="label"><a id="smpte2052"></a>SMPTE 2052-11</dt><dd>SMPTE 2052-11,
@@ -10408,7 +10408,7 @@
         &lt;span begin="3s"&gt;sit&lt;/span&gt;
       &lt;/p&gt;
       &lt;p&gt;
-        &lt;span begin="4s"&gt;Amet&lt;/span&gt;                
+        &lt;span begin="4s"&gt;Amet&lt;/span&gt;
         &lt;span begin="5s"&gt;consectetur&lt;/span&gt;
         &lt;span begin="6s"&gt;adipiscing&lt;/span&gt;
         &lt;span begin="7s"&gt;elit&lt;/span&gt;
@@ -10497,4 +10497,4 @@
 and example images of style properties), Sean Hayes (advanced profile
 concepts, including applicative timing, HTML/CSS mapping proposal), Erik Hodge (timing),
 Thierry Michel (metadata), and Dave Singer (animation, scrolling).</p><p>The editor also wishes to acknowledge the support of the following current and past sponsors of his work
-on this specification: Cox Communications, Netflix, Microsoft, and Samsung Electronics.</p><p>The Working Group dedicates this specification to our colleague David Kirby.</p></div></div></body></html>
\ No newline at end of file
+on this specification: Cox Communications, Netflix, Microsoft, and Samsung Electronics.</p><p>The Working Group dedicates this specification to our colleague David Kirby.</p></div></div></body></html>