[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">