New
authorPhilippe Le Hégaret <plh@w3.org>
Fri, 27 Aug 2010 00:22:32 +0000
changeset 208 0a3e58fea0bd
parent 207 8f6e087aeb65
child 209 5748d75a5392
New
spec/ttaf1-dfxp.html
--- a/spec/ttaf1-dfxp.html	Thu Aug 26 21:19:48 2010 +0000
+++ b/spec/ttaf1-dfxp.html	Fri Aug 27 00:22:32 2010 +0000
@@ -417,11 +417,11 @@
 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/>
-    J.1 <a href="#d3e17015">Element Derivation</a><br/>
-    J.2 <a href="#d3e17494">Attribute Derivation</a><br/>
+    J.1 <a href="#d3e17052">Element Derivation</a><br/>
+    J.2 <a href="#d3e17531">Attribute Derivation</a><br/>
 K <a href="#qa">QA Framework Compliance</a> (Non-Normative)<br/>
-    K.1 <a href="#d3e18382">Requirements</a><br/>
-    K.2 <a href="#d3e18546">Guidelines</a><br/>
+    K.1 <a href="#d3e18419">Requirements</a><br/>
+    K.2 <a href="#d3e18583">Guidelines</a><br/>
 L <a href="#streaming">Streaming TTML Content</a> (Non-Normative)<br/>
 M <a href="#acknowledgments">Acknowledgments</a> (Non-Normative)<br/>
 N <a href="#change-history">Change History</a> (Non-Normative)<br/>
@@ -6794,17 +6794,13 @@
 <a href="http://www.w3.org/2002/06/registering-mediatype.html">W3CRegMedia</a>.
 The information in this appendix is being submitted to the Internet
 Engineering Steering Group (IESG) for review, approval, and
-registration with the Internet Assigned Numbers Authority (IANA).</p><dl><dt class="label">MIME media type name:</dt><dd><p>application</p></dd><dt class="label">MIME subtype name:</dt><dd><p>ttml+xml</p></dd><dt class="label">Required parameters:</dt><dd><p>None.</p></dd><dt class="label">Optional parameters:</dt><dd><p>The encoding of a TTML document must be determined by the XML
-encoding declaration. This has identical semantics to the
-application/xml media type in the case where the charset parameter is
-omitted, as specified in <a href="#xml-media">[XML Media]</a>, Sections 8.9,
-8.10 and 8.11.</p><p>The document profile of a TTML document may be specified using
+registration with the Internet Assigned Numbers Authority (IANA).</p><dl><dt class="label">MIME media type name:</dt><dd><p>application</p></dd><dt class="label">MIME subtype name:</dt><dd><p>ttml+xml</p></dd><dt class="label">Required parameters:</dt><dd><p>None.</p></dd><dt class="label">Optional parameters:</dt><dd><dl><dt class="label">charset</dt><dd><p>Same as application/xml media type, as specified in <a href="#rfc3023">[XML Media Types]</a> or its successors.</p></dd><dt class="label">profile</dt><dd><p>The document profile of a TTML document may be specified using
 an optional <code>profile</code> parameter, which, if specified,
 the value of which must adhere to the syntax and semantics of
 <code>ttp:profile</code> parameter defined by
 Section
 <a href="#parameter-attribute-profile"><b>6.2.8 ttp:profile</b></a>
-of the published specification.</p></dd><dt class="label">Encoding considerations:</dt><dd><p>Same for application/xml. See <a href="#xml-media">[XML Media]</a>, Section
+of the published specification.</p></dd></dl></dd><dt class="label">Encoding considerations:</dt><dd><p>Same for application/xml. See <a href="#xml-media">[XML Media]</a>, Section
 3.2.</p></dd><dt class="label">Restrictions on usage:</dt><dd><p>None.</p></dd><dt class="label">Security considerations:</dt><dd><p>As with other XML types and as noted in
 <a href="#xml-media">[XML Media]</a>
 Section 10, repeated expansion of maliciously constructed XML entities
@@ -6825,8 +6821,8 @@
 expect 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></dd><dt class="label">Published specification:</dt><dd><p>This media type registration is extracted from Appendix <a href="#media-type-registration"><b>C Media Type Registration</b></a> of the <a href="http://www.w3.org/TR/ttaf1-dfxp/">Timed Text Markup Language (TTML) 1.0</a>
-specification.</p></dd><dt class="label">Additional information:</dt><dd><p>None.</p></dd><dt class="label">Person &amp; email address to contact for further information:</dt><dd><p>Glenn Adams ([email protected])</p></dd><dt class="label">Intended usage:</dt><dd><p>COMMON</p></dd><dt class="label">Author/Change controller:</dt><dd><p>The published specification is a work product of the World Wide Web
+in the document.</p><p/></dd><dt class="label">Published specification:</dt><dd><p>This media type registration is extracted from Appendix <a href="#media-type-registration"><b>C Media Type Registration</b></a> of the <a href="http://www.w3.org/TR/ttaf1-dfxp/">Timed Text Markup Language (TTML) 1.0</a>
+specification.</p></dd><dt class="label">Additional information:</dt><dd><dl><dt class="label">Magic number(s):</dt><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">Macintosh Universal Type Identifier code:</dt><dd><p>org.w3c.ttml conforms to public.xml</p></dd><dt class="label">Windows Clipboard Name:</dt><dd><p>"Timed Text Document"</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">Author/Change controller:</dt><dd><p>The published specification is a work product of the World Wide Web
 Consortium's Timed Text (TT) Working Group. The W3C has change control
 over this specification.</p></dd></dl></div><div class="div1">
 <h2><a name="features" id="features"/>D Features</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies (1) a set of feature designations, each of which
@@ -8331,7 +8327,7 @@
 <h2><a name="derivation" id="derivation"/>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 name="d3e17015" id="d3e17015"/>J.1 Element Derivation</h3><p>The first column of <a href="#element-vocab-derivation-table"><b>Table K-1 – Elements</b></a>
+<h3><a name="d3e17052" id="d3e17052"/>J.1 Element Derivation</h3><p>The first column of <a href="#element-vocab-derivation-table"><b>Table K-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
@@ -8386,7 +8382,7 @@
 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 name="d3e17494" id="d3e17494"/>J.2 Attribute Derivation</h3><p>The first column of <a href="#attribute-vocab-derivation-table"><b>Table K-2 – Attributes</b></a>
+<h3><a name="d3e17531" id="d3e17531"/>J.2 Attribute Derivation</h3><p>The first column of <a href="#attribute-vocab-derivation-table"><b>Table K-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
@@ -8458,9 +8454,9 @@
 <h2><a name="qa" id="qa"/>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> <a href="#qaf-sg">[QAF SG]</a>.</p><div class="div2">
-<h3><a name="d3e18382" id="d3e18382"/>K.1 Requirements</h3><table summary="HTML Table" id="qa-framework-requirements-table" class="common"><caption>Table L-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 name="d3e18419" id="d3e18419"/>K.1 Requirements</h3><table summary="HTML Table" id="qa-framework-requirements-table" class="common"><caption>Table L-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/></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/></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/></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/></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/></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/></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/></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/></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/></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/></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/></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>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>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 name="d3e18546" id="d3e18546"/>K.2 Guidelines</h3><table summary="HTML Table" id="qa-framework-guidelines-table" class="common"><caption>Table L-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/></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/></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/></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>NO</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/></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/></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/></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>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/></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>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/></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>NO</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/></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/></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/></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/></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/></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/></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/></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>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>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>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/></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 name="d3e18583" id="d3e18583"/>K.2 Guidelines</h3><table summary="HTML Table" id="qa-framework-guidelines-table" class="common"><caption>Table L-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/></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/></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/></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>NO</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/></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/></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/></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>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/></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>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/></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>NO</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/></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/></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/></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/></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/></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/></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/></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>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>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>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/></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
 <a href="#doctypes">TTML 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">