[ttml10se] regenerate ED
authorGlenn Adams <glenn@skynav.com>
Thu, 27 Jun 2013 03:11:03 -0600
changeset 412 216a924eba20
parent 411 b6b0d54ae5bc
child 413 0fe7753bea57
[ttml10se] regenerate ED
ttml10/spec/ttaf1-dfxp.html
--- a/ttml10/spec/ttaf1-dfxp.html	Thu Jun 27 03:10:04 2013 -0600
+++ b/ttml10/spec/ttaf1-dfxp.html	Thu Jun 27 03:11:03 2013 -0600
@@ -80,9 +80,9 @@
 .strong { font-weight: bold }
 .reqattr { font-weight: bold }
 .optattr { font-style: italic }
-</style><link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-ED.css"></head><body>Last Modified: $Date: 2013/06/20 04:35:40 $<div id="revisions"></div><div class="head">
+</style><link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-ED.css"></head><body>Last Modified: $Date: 2013/06/27 09:10:04 $<div id="revisions"></div><div class="head">
 <h1><a id="title"></a>Timed Text Markup Language (TTML) 1.0 (Second Edition)</h1>
-<h2><a id="w3c-doctype"></a>Editors' copy $Date: 2013/06/20 04:35:40 $ @@ @@@@ @@@@</h2><dl><dt>This version:</dt><dd>
+<h2><a id="w3c-doctype"></a>Editors' copy $Date: 2013/06/27 09:10:04 $ @@ @@@@ @@@@</h2><dl><dt>This version:</dt><dd>
 <a href="ttaf1-dfxp.html">ttaf1-dfxp.html</a>
 </dd><dt>Latest version:</dt><dd><a href="http://dvcs.w3.org/hg/ttml/raw-file/tip/ttml10/spec/ttaf1-dfxp.html?content-type=text/html;charset=utf-8">http://dvcs.w3.org/hg/ttml/raw-file/tip/ttml10/spec/ttaf1-dfxp.html?content-type=text/html;charset=utf-8</a></dd><dt>Previous version:</dt><dd>
 <a href="http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/">http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/</a>
@@ -392,11 +392,11 @@
 H <a href="#other-references">Other References</a> (Non-Normative)<br>
 I <a href="#requirements">Requirements</a> (Non-Normative)<br>
 J <a href="#derivation">Vocabulary Derivation</a> (Non-Normative)<br>
-&nbsp;&nbsp;&nbsp;&nbsp;J.1 <a href="#d3e18552">Element Derivation</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;J.2 <a href="#d3e19031">Attribute Derivation</a><br>
+&nbsp;&nbsp;&nbsp;&nbsp;J.1 <a href="#d3e18559">Element Derivation</a><br>
+&nbsp;&nbsp;&nbsp;&nbsp;J.2 <a href="#d3e19038">Attribute Derivation</a><br>
 K <a href="#qa">QA Framework Compliance</a> (Non-Normative)<br>
-&nbsp;&nbsp;&nbsp;&nbsp;K.1 <a href="#d3e19917">Requirements</a><br>
-&nbsp;&nbsp;&nbsp;&nbsp;K.2 <a href="#d3e20081">Guidelines</a><br>
+&nbsp;&nbsp;&nbsp;&nbsp;K.1 <a href="#d3e19924">Requirements</a><br>
+&nbsp;&nbsp;&nbsp;&nbsp;K.2 <a href="#d3e20088">Guidelines</a><br>
 L <a href="#streaming">Streaming TTML Content</a> (Non-Normative)<br>
 M <a href="#concrete-encoding">Concrete Encoding</a> (Non-Normative)<br>
 N <a href="#time-expression-semantics">Time Expression Semantics</a> (Non-Normative)<br>
@@ -601,7 +601,7 @@
 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>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>TT AS</b></td><td class="def"><p>Timed Text Authoring System</p></td></tr><tr><td class="label"><b>TT AF</b></td><td class="def"><p>Timed Text Authoring Format</p></td></tr><tr><td class="label"><b>TT WG</b></td><td class="def"><p>Timed Text Working Group</p></td></tr></table></div><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>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">Abstract Document Instance</dt><dd><p>An instance of an abstract data set as represented by a
 <em>Reduced XML Infoset</em>.</p></dd><dt class="label">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">Attribute Information Item</dt><dd><p>Each specified or defaulted attribute  of an XML document corresponds with an attribute information
@@ -863,9 +863,11 @@
 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>dfxp-presentation</code>, then the absolutized profile designator
 would be
-<code>http://www.w3.org/ns/ttml/profile/dfxp-presentation</code>.</p></div><p>A profile designator is not restricted to the set of designators enumerated
-in <a href="#profile-vocab-table"><b>Table 2 – Profiles</b></a>, but may be any URI that
-feasibly dereferences a TTML <em>Profile Definition Document</em>.</p><p>The profile of TTML that must be supported by a
+<code>http://www.w3.org/ns/ttml/profile/dfxp-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 2 – Profiles</b></a> are reserved for future standardization, and must not be appear in a conformant
+<em>Document Instance</em>. Nothwithstanding this constraint, a profile designator is not restricted to the set of designators enumerated
+in <a href="#profile-vocab-table"><b>Table 2 – Profiles</b></a>, but may be any URI that feasibly dereferences a TTML <em>Profile Definition Document</em>
+provided it does not use the TT Profile Namespace as a prefix.</p><p>The profile of TTML that must be supported by a
 TTML <em>Content Processor</em> in order to process a <em>Document Instance</em> is determined either (1) by specifying a
 <code>ttp:profile</code> attribute on the root <code>tt</code> element, as
 defined by <a href="#parameter-attribute-profile"><b>6.2.8 ttp:profile</b></a>, or (2) by
@@ -1423,7 +1425,7 @@
 is disallowed or otherwise prohibited.</p></div><p>The <code>ttp:extension</code> element is illustrated by the following example.</p><a id="parameter-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/dfxp-transformation"&gt;
-  &lt;ttp:extensions xml:base="http://example.org/ttaf1/extension/"&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;
@@ -1457,13 +1459,12 @@
 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><div class="note"><p class="prefix"><b>Note:</b></p><p>Except where indicated otherwise, when a <a href="#style-value-length">&lt;length&gt;</a> expressed in
-cells expresses a dimension parallel to the inline or block progression dimension,
-the cell's dimension in the inline or block progression dimension applies, respectively.
-For example, if padding (on all four edges) is specified as 0.1c, the cell resolution
+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 <em>Root Container Region</em> 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">
+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>6.2.2 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>6.2.11 ttp:timeBase</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#timing-time-value-expressions"><b>10.3 Time Value Expressions</b></a> for the
@@ -3889,7 +3890,8 @@
 element group apply semantically to the <code>region</code> element.
 Any <code>style</code> child element must be considered a local style
 definition that applies only to the containing <code>region</code>
-element, i.e., does not apply for resolving referential styling.</p><a id="elt-syntax-region"></a><table class="syntax"><caption>XML Representation – Element Information Item: region</caption><tbody><tr><td>
+element, i.e., does not apply for resolving referential styling (but does apply for region
+style inheritance).</p><a id="elt-syntax-region"></a><table class="syntax"><caption>XML Representation – Element Information Item: region</caption><tbody><tr><td>
 <div class="exampleInner"><pre>
 &lt;region
   <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
@@ -3981,13 +3983,14 @@
 form, <em>DOC<sub>source</sub></em> , 
 to an intermediate
 synchronic document form,
-<em>DOC<sub>inter</sub></em> , as follows:</p><dl><dt class="label">[construct intermediate document]</dt><dd><ol class="enumar"><li><p>for each temporally active region <em>R</em>, replicate the
+<em>DOC<sub>inter</sub></em> , according to the
+<span class="strong">[construct intermediate document]</span> procedure:</p><dl><dt class="label">[construct intermediate document]</dt><dd><ol class="enumar"><li><p>for each temporally active region <em>R</em>, replicate the
 sub-tree
  of <em>DOC<sub>source</sub></em>
 headed by the <code>body</code> element;</p></li><li><p>evaluating this sub-tree in a postorder traversal, prune elements if they
 are not a content element, if they are temporally inactive, if they are empty,
 or if they aren't associated with region <em>R</em> according to the
-<span class="strong">[associate region]</span>;</p></li><li><p>if the pruned sub-tree is non-empty, then reparent it to the <em>R</em>
+<span class="strong">[associate region]</span> procedure;</p></li><li><p>if the pruned sub-tree is non-empty, then reparent it to the <em>R</em>
 element;</p></li><li><p>finally, after completing the above steps, prune the original <code>body</code>
 element from the intermediate document, then prune all <code>region</code>,
 <code>begin</code>, <code>end</code>, and <code>dur</code> attributes, which are no
@@ -4156,7 +4159,7 @@
 containing two paragraphs. This content is targeted (associated with) one of two
 non-overlapping regions that are styled identically except for their position
 and their foreground colors, the latter of which is inherited by and applies to
-the (and, in this case, anonymous) spans reparented into the regions.</p><p>The following, first intermediate document shows the synchronic state at time
+the (and, in this case, anonymous) spans reparented into the regions.</p><p>The following, first intermediate document shows the synchronic state for time
 interval [0,1), during which time only division <code>d1</code> is temporally active,
 and where paragraphs <code>p1</code> and <code>p2</code> (and their ancestors)
 are associated with regions <code>r1</code> and <code>r2</code>, respectively.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The intermediate documents shown below are not valid <em>Document Instances</em>,
@@ -4269,8 +4272,8 @@
   &lt;/fo:page-sequence&gt;
 &lt;/fo:root&gt;
 </pre></div>
-</td></tr></tbody></table><p>The following, second intermediate document shows the synchronic state at
-time interval [1,2), at which time both divisions <code>d1</code> and
+</td></tr></tbody></table><p>The following, second intermediate document shows the synchronic state for
+time interval [1,2), during which time both divisions <code>d1</code> and
 <code>d2</code> are temporally active, and where paragraphs <code>p1</code> and
 <code>p4</code> (and their ancestors) are associated with region <code>r1</code>
 and paragraphs <code>p2</code> and <code>p3</code> (and their ancestors) are
@@ -4320,8 +4323,8 @@
   &lt;/head&gt;
 &lt;/tt&gt;
 </pre></div>
-</td></tr></tbody></table><p>The following, third intermediate document shows the synchronic state at time
-interval [2,3), at which time only division <code>d2</code> is temporally active,
+</td></tr></tbody></table><p>The following, third intermediate document shows the synchronic state for time
+interval [2,3), during which time only division <code>d2</code> is temporally active,
 and where paragraphs <code>p4</code> and <code>p3</code> (and their ancestors)
 are associated with regions <code>r1</code> and <code>r2</code>, respectively.</p><a id="region-mapping-example-1-i2"></a><table class="example"><caption>Example – Intermediate Document – [2s,3s)</caption><tbody><tr><td>
 <div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
@@ -4487,9 +4490,9 @@
 </pre></div>
 </td></tr></tbody></table><p>If a &lt;timeExpression&gt; is expressed in terms of a
 <em>clock-time</em>, then leading zeroes are used when expressing hours,
-minutes, seconds, and frames less than 10. Minutes are constrained to the range
-[0…59], while seconds are constrained to [0…60], where the value 60
-applies only to leap seconds.</p><p>If a &lt;timeExpression&gt; is expressed in terms of a
+minutes, seconds, and frames less than 10. Minutes are constrained to
+[0…59], while seconds (including any fractional part) are constrained to the closed
+interval [0,60], where the value 60 applies only to leap seconds.</p><p>If a &lt;timeExpression&gt; is expressed in terms of a
 <em>clock-time</em> and a <em>frames</em> term is specified,
 then the value of this term must be constrained to the interval
 [0…<em>F-1</em>], where <em>F</em> is the frame rate
@@ -4611,7 +4614,7 @@
 semantics depend entirely upon an application's use of TTML Content.</p><div class="div2">
 <h3><a id="metadata-element-vocabulary"></a>12.1 Metadata Element Vocabulary</h3><p>The <a href="#metadata-vocabulary-metadata"><b>12.1.1 metadata</b></a> element serves as
 a generic container element for grouping metadata information.</p><p>In addition, the following elements, all defined in the TT Metadata Namespace,
-provide standard representations for common metadata that is expected to be commonly
+provide standard representations for metadata that is expected to be commonly
 used in a <em>Document Instances</em>:
 </p><ul><li><p><a href="#metadata-vocabulary-title"><b>12.1.2 ttm:title</b></a></p></li><li><p><a href="#metadata-vocabulary-desc"><b>12.1.3 ttm:desc</b></a></p></li><li><p><a href="#metadata-vocabulary-copyright"><b>12.1.4 ttm:copyright</b></a></p></li><li><p><a href="#metadata-vocabulary-agent"><b>12.1.5 ttm:agent</b></a></p></li><li><p><a href="#metadata-vocabulary-name"><b>12.1.6 ttm:name</b></a></p></li><li><p><a href="#metadata-vocabulary-actor"><b>12.1.7 ttm:actor</b></a></p></li></ul><div class="div3">
 <h4><a id="metadata-vocabulary-metadata"></a>12.1.1 metadata</h4><p>The <code>metadata</code> element functions as a generic container for metadata
@@ -4661,7 +4664,7 @@
 </td></tr></tbody></table><p></p><p>The use of metadata attribute items is illustrated by the following example.</p><a id="metadata-vocabulary-metadata-example-3"></a><table class="example"><caption>Example Fragment – Foreign Metadata Attribute Items</caption><tbody><tr><td>
 <div class="exampleInner"><pre>
 ...
-&lt;div xmlns:ext="http://example.org/ttaf1#metadata"&gt;
+&lt;div xmlns:ext="http://example.org/ttml#metadata"&gt;
   &lt;metadata ext:ednote="remove this division prior to publishing"/&gt;
 &lt;/div&gt;
 ...
@@ -4931,13 +4934,15 @@
 or encryption would normally be employed.</p></dd><dt class="label">Interoperability considerations:</dt><dd><p>The published specification describes processing semantics that dictate
 behavior that must be followed when dealing with, among other things,
 unrecognized elements and attributes, both in TTML namespaces and in
-other namespaces.</p><p>Because TTML is extensible, conformant "application/ttml+xml" processors must
-expect that content received is well-formed XML, but it cannot be
+other namespaces.</p><p>Because TTML is extensible, conformant "application/ttml+xml" processors may
+expect (and enforce) that content received is well-formed XML, but it cannot be
 guaranteed that the content is valid to a particular DTD or Schema or
 that the processor will recognize all of the elements and attributes
 in the document.</p><p></p></dd><dt class="label">Published specification:</dt><dd><p>This media type registration is extracted from Appendix C Media Type
 Registration of the Timed Text Markup Language (TTML) 1.0 specification:
-<a href="http://www.w3.org/TR/ttaf1-dfxp/">Timed Text Markup Language (TTML) 1.0</a>.</p></dd><dt class="label">Applications that use this media type:</dt><dd><p>    TTML is used in the television industry for the purpose of authoring, transcoding and exchanging timed text information and for delivering captions for television material repurposed for the internet.</p><p>There is partial and full support of TTML in components used by several Web browsers plugins, and in a number of caption authoring tools.</p></dd><dt class="label">Additional information:</dt><dd><dl><dt class="label">Magic number(s):</dt><dd></dd><dt class="label">File extension(s):</dt><dd><p>.ttml</p></dd><dt class="label">Macintosh file type code(s):</dt><dd><p>"TTML"</p></dd><dt class="label">Fragment identifiers:</dt><dd><p>For documents labeled as application/ttml+xml, the fragment identifier notation is intended to be used with xml:id attributes, as described in section 7.2.1 of the <a href="http://www.w3.org/TR/ttaf1-dfxp/">Timed Text Markup Language (TTML) 1.0</a> specification.</p></dd></dl></dd><dt class="label">Person &amp; email address to contact for further information:</dt><dd><p>Timed Text Working Group ([email protected])</p></dd><dt class="label">Intended usage:</dt><dd><p>COMMON</p></dd><dt class="label">Restrictions on usage:</dt><dd><p>None</p></dd><dt class="label">Author:</dt><dd><p>The published specification is a work product of the World Wide Web
+<a href="http://www.w3.org/TR/ttaf1-dfxp/">Timed Text Markup Language (TTML) 1.0</a>.</p></dd><dt class="label">Applications that use this media type:</dt><dd><p>TTML is used in the television industry for the purpose of authoring, transcoding and exchanging timed text information and for delivering captions, subtitles, and
+other metadata for television material repurposed for the Web or, more generally, the Internet.</p><p>There is partial and full support of TTML in components used by several Web browsers plugins, and in a number of caption authoring tools. A TTML verification (including
+validation) utility is available in open source form at <a href="http://github.com/skynav/ttv">http://github.com/skynav/ttv</a>.</p></dd><dt class="label">Additional information:</dt><dd><dl><dt class="label">Magic number(s):</dt><dd></dd><dt class="label">File extension(s):</dt><dd><p>.ttml</p></dd><dt class="label">Macintosh file type code(s):</dt><dd><p>"TTML"</p></dd><dt class="label">Fragment identifiers:</dt><dd><p>For documents labeled as application/ttml+xml, the fragment identifier notation is intended to be used with xml:id attributes, as described in section 7.2.1 of the <a href="http://www.w3.org/TR/ttaf1-dfxp/">Timed Text Markup Language (TTML) 1.0</a> specification.</p></dd></dl></dd><dt class="label">Person &amp; email address to contact for further information:</dt><dd><p>Timed Text Working Group ([email protected])</p></dd><dt class="label">Intended usage:</dt><dd><p>COMMON</p></dd><dt class="label">Restrictions on usage:</dt><dd><p>None</p></dd><dt class="label">Author:</dt><dd><p>The published specification is a work product of the World Wide Web
 Consortium's Timed Text (TT) Working Group.</p></dd><dt class="label">Change controller:</dt><dd><p>The W3C has change control over this specification.</p></dd></dl></div><div class="div1">
 <h2><a id="features"></a>D Features</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies (1) a set of feature designations, each of which
 labels one or more syntactic and/or semantic features defined by this
@@ -5927,7 +5932,7 @@
 <a href="#parameter-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>.</p><div class="div2">
 <h3><a id="profile-dfxp-transformation"></a>F.1 DFXP Transformation Profile</h3><p>The DFXP Transformation Profile is intended to be used to
 express minimum compliance for transformation processing.</p><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;!-- this file defines the "dfxp-transformation" profile of ttaf1 --&gt;
+&lt;!-- this file defines the "dfxp-transformation" profile of ttml --&gt;
 &lt;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
   &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
     &lt;!-- required (mandatory) feature support --&gt;
@@ -6056,7 +6061,7 @@
 </pre></div></div><div class="div2">
 <h3><a id="profile-dfxp-presentation"></a>F.2 DFXP Presentation Profile</h3><p>The DFXP Presentation Profile is intended to be used to
 express minimum compliance for presentation processing.</p><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;!-- this file defines the "dfxp-presentation" profile of ttaf1-dfxp --&gt;
+&lt;!-- this file defines the "dfxp-presentation" profile of ttml --&gt;
 &lt;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
   &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
     &lt;!-- required (mandatory) feature support --&gt;
@@ -6185,7 +6190,7 @@
 </pre></div></div><div class="div2">
 <h3><a id="profile-dfxp-full"></a>F.3 DFXP Full Profile</h3><p>The DFXP Full Profile is intended to be used to
 express maximum compliance for both transformation and presentation processing.</p><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;!-- this file defines the "dfxp-full" profile of ttaf1-dfxp --&gt;
+&lt;!-- this file defines the "dfxp-full" profile of ttml --&gt;
 &lt;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
   &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
     &lt;!-- required (mandatory) feature support --&gt;
@@ -6460,8 +6465,8 @@
 August 2002. (See
 <a href="http://www.w3.org/TR/2002/REC-xhtml1-20020801/">http://www.w3.org/TR/2002/REC-xhtml1-20020801/</a>.)
 </dd></dl></div><div class="div1">
-<h2><a id="requirements"></a>I Requirements (Non-Normative)</h2><p>The Distribution Format Exchange Profile (DFXP) of the Timed Text Authoring
-Format (TTML) satisfies a subset of the requirements established by
+<h2><a id="requirements"></a>I Requirements (Non-Normative)</h2><p>The Timed Text Markup Language (TTML), also known as the Distribution Format Exchange Profile (DFXP) of the Timed Text Authoring
+Format (TTAF), satisfies a subset of the requirements established by
 <a href="#ttaf1-req">[TTAF1-REQ]</a>. The following table enumerates these requirements and
 indicates the extent to which they are satisfied by this specification, where
 <em>S</em> denotes a requirement is satisfied, <em>P</em> denotes
@@ -6473,7 +6478,7 @@
 <h2><a id="derivation"></a>J Vocabulary Derivation (Non-Normative)</h2><p>This appendix provides information about the derivation of TTML
 vocabulary, separately describing derivation of elements and
 attributes.</p><div class="div2">
-<h3><a id="d3e18552"></a>J.1 Element Derivation</h3><p>The first column of <a href="#element-vocab-derivation-table"><b>Table J-1 – Elements</b></a>
+<h3><a id="d3e18559"></a>J.1 Element Derivation</h3><p>The first column of <a href="#element-vocab-derivation-table"><b>Table J-1 – Elements</b></a>
 specifies a TTML element vocabulary item; the second column specifies the
 syntactic and/or semantic model on which the vocabulary item is based;
 the third column specifies the reference that defines
@@ -6528,7 +6533,7 @@
 and <code>@requiredFeatures</code> on the <code>svg:svg</code> element,
 but extended to support distinct specification of optionality.</p></li><li><p>Derived from the use of <code>@baseProfile</code>
 and <code>@version</code> on the <code>svg:svg</code> element.</p></li></ol></div></div><div class="div2">
-<h3><a id="d3e19031"></a>J.2 Attribute Derivation</h3><p>The first column of <a href="#attribute-vocab-derivation-table"><b>Table J-2 – Attributes</b></a>
+<h3><a id="d3e19038"></a>J.2 Attribute Derivation</h3><p>The first column of <a href="#attribute-vocab-derivation-table"><b>Table J-2 – Attributes</b></a>
 specifies a TTML attribute vocabulary item; the second column specifies the
 syntactic and/or semantic model on which the vocabulary item is based;
 the third column specifies the reference that defines
@@ -6600,9 +6605,9 @@
 <h2><a id="qa"></a>K QA Framework Compliance (Non-Normative)</h2><p>This appendix specifies the compliance of this specification with the
 requirements and guidelines defined by <a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/">QA
 Framework Specifications Guidelines</a>&nbsp;<a href="#qaf-sg">[QAF SG]</a>.</p><div class="div2">
-<h3><a id="d3e19917"></a>K.1 Requirements</h3><a id="qa-framework-requirements-table"></a><table class="common"><caption>Table K-1 – QA Framework Requirements Checklist</caption><col width="76%" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><tbody><tr><td><span class="strong">Requirement</span></td><td><span class="strong">YES</span></td><td><span class="strong">NO</span></td><td><span class="strong">N/A</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#include-conformance-clause-principle">Requirement 01: Include a conformance
+<h3><a id="d3e19924"></a>K.1 Requirements</h3><a id="qa-framework-requirements-table"></a><table class="common"><caption>Table K-1 – QA Framework Requirements Checklist</caption><col width="76%" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><tbody><tr><td><span class="strong">Requirement</span></td><td><span class="strong">YES</span></td><td><span class="strong">NO</span></td><td><span class="strong">N/A</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#include-conformance-clause-principle">Requirement 01: Include a conformance
 clause</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-scope-principle">Requirement 02: Define the scope.</a></td><td><a href="#intro">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#implement-principle">Requirement 03: Identify who or what will implement the specification.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ref-norm-principle">Requirement 04: Make a list of normative references.</a></td><td><a href="#references">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-terms-principle">Requirement 05: Define the terms used in the normative parts of the specification.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conf-label-principle">Requirement 06: Create conformance labels for each part of the conformance model.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#consistent-style-principle">Requirement 07: Use a consistent style for conformance requirements and explain how to distinguish them.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#req-opt-conf-principle">Requirement 08: Indicate which conformance requirements are mandatory, which are recommended, and which are optional.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdivide-mandatory-principle">Requirement 09: If the technology is subdivided, then indicate which subdivisions are mandatory for conformance.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdiv-constraints-principle">Requirement 10: If the technology is subdivided, then address subdivision constraints.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#likehood-extension-principle">Requirement 11: Address Extensibility.</a></td><td><a href="#doctypes">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#deprecated-feature-principle">Requirement 12: Identify deprecated features.</a></td><td></td><td></td><td>N/A</td><td>1</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#degree-support-principle">Requirement 13: Define how each class of product handles each deprecated feature.</a></td><td></td><td></td><td>N/A</td><td>1</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>No feature is deprecated by this version of this specification.</p></li></ol></div></div><div class="div2">
-<h3><a id="d3e20081"></a>K.2 Guidelines</h3><a id="qa-framework-guidelines-table"></a><table class="common"><caption>Table K-2 – QA Framework Guidelines Checklist</caption><col width="76%" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><tbody><tr><td><span class="strong">Guideline</span></td><td><span class="strong">YES</span></td><td><span class="strong">NO</span></td><td><span class="strong">N/A</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conformance-model-gp">Good Practice 01: Define the specification's conformance model in the conformance clause.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#norm-informative-gp">Good Practice 02: Specify in the conformance clause how to distinguish normative from informative content.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conformance-claim-gp">Good Practice 03: Provide the wording for conformance claims.</a></td><td><a href="#claims">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ics-gp">Good Practice 04: Provide an Implementation Conformance Statement Pro Forma.</a></td><td></td><td>NO</td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ics-claim-gp">Good Practice 05: Require an Implementation Conformance Statement as part of valid conformance claims.</a></td><td><a href="#claims">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#use-example-gp">Good Practice 06: Provide examples, use cases, and graphics.</a></td><td><a href="#example">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#write-sample-gp">Good Practice 07: Write sample code or tests.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ref-define-practice">Good Practice 08: When imposing requirements by normative references, address conformance dependencies.</a></td><td><a href="#references">YES</a></td><td></td><td></td><td>1</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-terms-inline-gp">Good Practice 09: Define unfamiliar terms in-line and consolidate the definitions in a glossary section.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#reuse-terms-gp">Good Practice 10: Use terms already defined without changing their definition.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td>2</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#formal-language-gp">Good Practice 11: Use formal languages when possible.</a></td><td><a href="#schemas">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#write-assertion-gp">Good Practice 12: Write Test Assertions.</a></td><td></td><td>NO</td><td></td><td>3</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdivide-foster-gp">Good Practice 13: Create subdivisions of the technology when warranted.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#rules-profiles-gp">Good Practice 14: If the technology is profiled, define rules for creating new profiles.</a></td><td><a href="#vocabulary-profiles">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#need-option-gp">Good Practice 15:Use optional features as warranted.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#label-options-gp">Good Practice 16: Clearly identify optional features.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#constraints-gp">Good Practice 17: Indicate any limitations or constraints on optional features.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#extensions-prohibited-gp">Good Practice 18: If extensibility is allowed, define an extension mechanism.</a></td><td><a href="#extension-vocabulary-overview">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#breaking-conformance-gp">Good Practice 19: Warn extension creators to create extensions that do not interfere with conformance.</a></td><td><a href="#extension-vocabulary-overview">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-error-gp">Good Practice 20: Define error-handling for unknown extensions.</a></td><td><a href="#conformance-processor">YES</a></td><td></td><td></td><td>4</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#workaround-gp">Good Practice 21: Explain how to avoid using a deprecated feature.</a></td><td></td><td></td><td>N/A</td><td>5</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#obsolete-gp">Good Practice 22: Identify obsolete features.</a></td><td></td><td></td><td>N/A</td><td>5</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#error-handling-gp">Good Practice 23: Define an error handling mechanism.</a></td><td><a href="#reduced-infoset">YES</a></td><td></td><td></td><td></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>When making normative references to external specifications,
+<h3><a id="d3e20088"></a>K.2 Guidelines</h3><a id="qa-framework-guidelines-table"></a><table class="common"><caption>Table K-2 – QA Framework Guidelines Checklist</caption><col width="76%" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><col width="6%" align="center" span="1"><tbody><tr><td><span class="strong">Guideline</span></td><td><span class="strong">YES</span></td><td><span class="strong">NO</span></td><td><span class="strong">N/A</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conformance-model-gp">Good Practice 01: Define the specification's conformance model in the conformance clause.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#norm-informative-gp">Good Practice 02: Specify in the conformance clause how to distinguish normative from informative content.</a></td><td><a href="#conventions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#conformance-claim-gp">Good Practice 03: Provide the wording for conformance claims.</a></td><td><a href="#claims">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ics-gp">Good Practice 04: Provide an Implementation Conformance Statement Pro Forma.</a></td><td></td><td>NO</td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ics-claim-gp">Good Practice 05: Require an Implementation Conformance Statement as part of valid conformance claims.</a></td><td><a href="#claims">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#use-example-gp">Good Practice 06: Provide examples, use cases, and graphics.</a></td><td><a href="#example">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#write-sample-gp">Good Practice 07: Write sample code or tests.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#ref-define-practice">Good Practice 08: When imposing requirements by normative references, address conformance dependencies.</a></td><td><a href="#references">YES</a></td><td></td><td></td><td>1</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-terms-inline-gp">Good Practice 09: Define unfamiliar terms in-line and consolidate the definitions in a glossary section.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#reuse-terms-gp">Good Practice 10: Use terms already defined without changing their definition.</a></td><td><a href="#definitions">YES</a></td><td></td><td></td><td>2</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#formal-language-gp">Good Practice 11: Use formal languages when possible.</a></td><td><a href="#schemas">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#write-assertion-gp">Good Practice 12: Write Test Assertions.</a></td><td></td><td>NO</td><td></td><td>3</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#subdivide-foster-gp">Good Practice 13: Create subdivisions of the technology when warranted.</a></td><td><a href="#conformance">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#rules-profiles-gp">Good Practice 14: If the technology is profiled, define rules for creating new profiles.</a></td><td><a href="#vocabulary-profiles">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#need-option-gp">Good Practice 15:Use optional features as warranted.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#label-options-gp">Good Practice 16: Clearly identify optional features.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#constraints-gp">Good Practice 17: Indicate any limitations or constraints on optional features.</a></td><td>YES</td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#extensions-prohibited-gp">Good Practice 18: If extensibility is allowed, define an extension mechanism.</a></td><td><a href="#extension-vocabulary-overview">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#breaking-conformance-gp">Good Practice 19: Warn extension creators to create extensions that do not interfere with conformance.</a></td><td><a href="#extension-vocabulary-overview">YES</a></td><td></td><td></td><td></td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#define-error-gp">Good Practice 20: Define error-handling for unknown extensions.</a></td><td><a href="#conformance-processor">YES</a></td><td></td><td></td><td>4</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#workaround-gp">Good Practice 21: Explain how to avoid using a deprecated feature.</a></td><td></td><td></td><td>N/A</td><td>5</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#obsolete-gp">Good Practice 22: Identify obsolete features.</a></td><td></td><td></td><td>N/A</td><td>5</td></tr><tr><td><a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/#error-handling-gp">Good Practice 23: Define an error handling mechanism.</a></td><td><a href="#reduced-infoset">YES</a></td><td></td><td></td><td></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>When making normative references to external specifications,
 specific clauses or sections are cited.</p></li><li><p>See also <a href="#derivation"><b>J Vocabulary Derivation</b></a>.</p></li><li><p>Test assertions and test suites will be provided prior to entering
 Proposed Recommendation (PR) phase.</p></li><li><p>See criterion #3 in <a href="#conformance-processor"><b>3.2 Processor Conformance</b></a> and definition of
 TTML <a href="#doctypes">Abstract Document Instance</a>.</p></li><li><p>No feature is deprecated or obsoleted by this version of this specification.</p></li></ol></div></div></div><div class="div1">
@@ -6634,14 +6639,14 @@
 <h2><a id="time-expression-semantics"></a>N Time Expression Semantics (Non-Normative)</h2><p>This appendix describes the intended semantics for interpreting time expressions in <em>Document Instances</em>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>It is expected that the information in this appendix will be elevated to normative status in a future revision of this specification.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The phrase <em>local real time</em> as used below is intended to model a virtual real time clock in the document processing context, where
 <em>local</em> means in the immediate proximity of the implementation of this processing context. The intent
 of defining relationships with this virtual clock is to establish a locally valid physical realization of time for didactic purposes.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The phrase <em>play rate</em> as used below is intended to model a (possibly variable) parameter in the document processing context wherein
-the rate of playback (or interpretation) of time may artificially dilated or narrowed, for example, when speeding up or slowing down the rate of
+the rate of playback (or interpretation) of time may artificially dilated or narrowed, for example, when slowing down or speeding up the rate of
 playback of a <em>Related Media Object</em>. Without loss of generality, the following discussion assumes a fixed play(back) rate. In the case of
 variable play rates, appropriate adjustments may need to be made to the resulting computations.</p></div><div class="div2">
 <h3><a id="time-expression-semantics-clock"></a>N.1 Clock Time Base</h3><p>When operating with the <code>clock</code> time base, the following semantics should be applied for interpreting time expressions,
 as defined by <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, and their relationship to media time and local real time.</p><p>The clock time base <span class="strong"><code>C</code></span> is related to local real time <span class="strong"><code>R</code></span>
 expressed in an arbitrary (implementation defined) epoch <span class="strong"><code>E</code></span>
 as follows:</p><a id="clock-time-and-real-time"></a><table class="semantics"><caption>TTML Semantics – Clock Time and Real Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
+<blockquote><p><br>
 <code>R = C + epochOffset + discontinuityOffset</code>
 <br><br>
 where <code>C ∈ ℜ</code>, <code>0 ≤ C &lt; ∞</code>, <code>C</code> in seconds since the most immediately prior midnight of the reference clock base;
@@ -6668,7 +6673,7 @@
 <br></p></blockquote>
 </td></tr></tbody></table><p>Time value expressions, as denoted by a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, are related to
 clock time <span class="strong"><code>C</code></span> as follows:</p><a id="time-expressions-and-clock-time"></a><table class="semantics"><caption>TTML Semantics – Time Expressions and Clock Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
+<blockquote><p><br>
 If a time expression uses the <em>clock-time</em> form or an <em>offset-time</em> form that doesn't use the ticks (<code>t</code>) metric, then:
 <br><br>
 <code>C = 3600 * hours + 60 * minutes + seconds</code>
@@ -6684,7 +6689,7 @@
 <br></p></blockquote>
 </td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The <em>frames</em> and <em>sub-frames</em> terms and the frames (<code>f</code>) metric of time expressions do not apply when using
 the <code>clock</code> time base.</p></div><p>The clock time base <span class="strong"><code>C</code></span> is independent of media time <span class="strong"><code>M</code></span>:</p><a id="clock-time-and-media-time"></a><table class="semantics"><caption>TTML Semantics – Clock Time and Media Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
+<blockquote><p><br>
 <code>M ¬∝ C</code>
 <br></p></blockquote>
 </td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>That is to say, timing is disconnected from (not necessarily proportional to) media time when
@@ -6695,7 +6700,7 @@
 <h3><a id="time-expression-semantics-media"></a>N.2 Media Time Base</h3><p>When operating with the <code>media</code> time base, the following semantics should be applied for interpreting time expressions,
 as defined by <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, and their relationship to media time and local real time.</p><p>The media time base <span class="strong"><code>M</code></span> is related to local real time <span class="strong"><code>R</code></span>
 expressed in an arbitrary (implementation defined) epoch <span class="strong"><code>E</code></span> as follows:</p><a id="media-time-and-real-time"></a><table class="semantics"><caption>TTML Semantics – Media Time and Real Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
+<blockquote><p><br>
 <code>R = playRate * M + epochOffset</code>
 <br><br>
 where <code>M ∈ ℜ</code>, <code>0 ≤ M &lt; ∞</code>, <code>M</code> in seconds, with 0 corresponding to the beginning of the <em>Root Temporal Extent</em>;
@@ -6710,15 +6715,20 @@
 </td></tr></tbody></table><p>Time value expressions, as denoted by a <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>, are related to
 media time <span class="strong"><code>M</code></span> in accordance to the
 <code>ttp:frameRate</code>, <code>ttp:subFrameRate</code>, and <code>ttp:frameRateMultipler</code> parameters as follows:</p><a id="time-expressions-and-media-time"></a><table class="semantics"><caption>TTML Semantics – Time Expressions and Media Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
+<blockquote><p><br>
 If a time expression uses a <em>clock-time</em> form or an <em>offset-time</em> form that doesn't use the ticks (<code>t</code>) metric, then:
 <br><br>
 <code>
-M = containerBegin + 3600 * hours + 60 * minutes + seconds + ((frames + (subFrames / subFrameRate)) / effectiveFrameRate)
+M = referenceBegin + 3600 * hours + 60 * minutes + seconds + ((frames + (subFrames / subFrameRate)) / effectiveFrameRate)
 </code>
 <br><br>
-where <code>containerBegin</code> is the media time that corresponds to the beginning of the nearest ancestor time container or
-zero (0) if this time container is the <em>Root Temporal Extent</em>;
+where <code>referenceBegin</code> is determined according to whether the nearest ancestor time container employs
+parallel (<code>par</code>) or sequential (<code>seq</code>) semantics: if parallel or if sequential and no prior sibling
+timed element exists, then <code>referenceBegin</code>
+is the media time that corresponds to the beginning of the nearest ancestor time container or
+zero (0) if this time container is the <em>Root Temporal Extent</em>; otherwise, if sequential and a prior sibling
+timed element exists, then <code>referenceBegin</code> is the media time that corresponds to the active end of the
+immediate prior sibling timed element;
 <br><br>
 the <code>hours</code>, <code>minutes</code>, <code>seconds</code>, <code>frames</code>, <code>subFrames</code> components
 are extracted from time expression if present, or zero if not present;
@@ -6732,10 +6742,10 @@
 Otherwise, if a time expression uses an <em>offset-time</em> form that uses the ticks (<code>t</code>) metric, then:
 <br><br>
 <code>
-M = containerBegin + ticks / tickRate
+M = referenceBegin + ticks / tickRate
 </code>
 <br><br>
-where <code>containerBegin</code> is as described above;
+where <code>referenceBegin</code> is as described above;
 <br><br>
 the <code>ticks</code> component is extracted from time expression;
 <br><br>
@@ -6750,7 +6760,7 @@
 Codes</em> are encountered in the <em>Related Media Object</em>.</p><p>Otherwise, if the computed value of the <code>ttp:markerMode</code> parameter is <code>continuous</code>, then the relationships between time expressions and
 local real time and media time are as described below in terms of a <em>Synthetic SMPTE Document Syncbase</em>, here referred to as the
 SMPTE time base <span class="strong"><code>S</code></span>.</p><a id="time-expressions-and-smpte-time"></a><table class="semantics"><caption>TTML Semantics – Time Expressions and SMPTE Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
+<blockquote><p><br>
 <code>S = (countedFrames - droppedFrames + (subFrames / subFrameRate)) / effectiveFrameRate</code>
 <br><br>where<br><br>
 <code>countedFrames = (3600 * hours + 60 * minutes + seconds) * frameRate + frames</code>
@@ -6784,11 +6794,16 @@
 should be considered to be invalid for purposes of validation assessment.
 <br></p></blockquote>
 </td></tr></tbody></table><p>The SMPTE time base <span class="strong"><code>S</code></span> is related to the media time base <span class="strong"><code>M</code></span> as follows:</p><a id="smpte-time-and-media-time"></a><table class="semantics"><caption>TTML Semantics – SMPTE Time and Media Time Relationship</caption><tbody><tr><td>
-<blockquote><p>
-<code>M = containerBegin + S</code>
+<blockquote><p><br>
+<code>M = referenceBegin + S</code>
 <br><br>
-where <code>containerBegin</code> is the SMPTE time that corresponds to the beginning of the nearest ancestor time container or
-zero (0) if this time container is the <em>Root Temporal Extent</em>;
+where <code>referenceBegin</code> is determined according to whether the nearest ancestor time container employs
+parallel (<code>par</code>) or sequential (<code>seq</code>) semantics: if parallel or if sequential and no prior sibling
+timed element exists, then <code>referenceBegin</code>
+is the SMPTE time that corresponds to the beginning of the nearest ancestor time container or
+zero (0) if this time container is the <em>Root Temporal Extent</em>; otherwise, if sequential and a prior sibling
+timed element exists, then <code>referenceBegin</code> is the SMPTE time that corresponds to the active end of the
+immediate prior sibling timed element;
 <br></p></blockquote>
 </td></tr></tbody></table><p>Given the derived media time base as described above, then 
 media time base <span class="strong"><code>M</code></span> is related to the local real time <span class="strong"><code>R</code></span>