--- a/ttml11/spec/build.xml	Wed Apr 11 23:21:22 2012 -0600
+++ b/ttml11/spec/build.xml	Wed Apr 11 23:50:28 2012 -0600
@@ -7,7 +7,7 @@
         <pathelement location="saxon8/saxon8.jar"/>
     </path>
     <property name="htmlOutputDir" value="./"/>
-    <property name="stylesheet" value="xmlspec-ttaf1-dfxp.xsl"/>
+    <property name="stylesheet" value="xmlspec-ttml11.xsl"/>
     <property name="glossary" value="extract-glist.xsl"/>
 	<property name="generateBPlist" value="generateBPlist.xsl"/>
     <property name="diffformat" value="diffspec.xsl"/>
@@ -15,7 +15,7 @@
     
     <property name="jing.jar" value="${basedir}/jing/jing.jar"/>
     <property name="rnc.dir" value="${basedir}/rnc"/>
-    <property name="rnc.schema" value="${rnc.dir}/ttaf1-dfxp.rnc"/>
+    <property name="rnc.schema" value="${rnc.dir}/ttml11.rnc"/>
     <property name="profiles.dir" value="${basedir}/profiles"/>
 
     <patternset id="escapable">
@@ -41,13 +41,13 @@
     </target>
 
     <target name="clean" depends="clean-escapes">
-        <delete quiet="true" file="ttaf1-dfxp.html"/>
+        <delete quiet="true" file="ttml11.html"/>
     </target>
 
     <target name="validate-schema-rnc" description="Validates DFXP's RNC Schema.">
         <java fork="true" jar="${jing.jar}" dir="${rnc.dir}">
             <arg value="-c"/>
-            <arg value="ttaf1-dfxp.rnc"/>
+            <arg value="ttml11.rnc"/>
         </java>
     </target>
 
@@ -107,7 +107,7 @@
 
     <target name="validate-tt-specs" description="Validates all Timed Text spec files."
         depends="build-escapes">
-        <xmlvalidate lenient="false" warn="yes" file="ttaf1-dfxp.xml"/>
+        <xmlvalidate lenient="false" warn="yes" file="ttml11.xml"/>
     </target>
 
     <target name="validate" depends="validate-xsl,validate-svg,validate-tt-specs,validate-schema-rnc,validate-profiles"/>
@@ -137,12 +137,12 @@
     </target>
 
     <target name="html" description="Transforms xml into html.">
-        <echo>Generating ttaf1-dfxp.html</echo>
+        <echo>Generating ttml11.html</echo>
         <java fork="true" classname="net.sf.saxon.Transform">
             <classpath refid="saxon8.classpath"/>
             <arg value="-o"/>
-            <arg value="${htmlOutputDir}ttaf1-dfxp.html"/>
-            <arg value="ttaf1-dfxp.xml"/>
+            <arg value="${htmlOutputDir}ttml11.html"/>
+            <arg value="ttml11.xml"/>
             <arg value="${stylesheet}"/>
             <arg value="showAssertions=true"/>
         </java>    
@@ -160,7 +160,7 @@
             <arg value="both"/>
             <arg value="-words"/>
             <arg value="tt-tr${last-public-draft}.xml"/>
-            <arg value="ttaf1-dfxp.xml"/>
+            <arg value="ttml11.xml"/>
             <arg value="tt-diff${last-public-draft}.xml"/>
             <classpath path="diffmk.jar:DiffMk.properties"> </classpath>
         </java>
@@ -192,7 +192,7 @@
 
     <target name="changelog" description="Update the CVS change log to be added into the specification">
       <!--        <cvschangelog destfile="changelog.xml"/> -->
-      <get src="http://www.w3.org/2000/06/webdata/xslt?xslfile=http%3A%2F%2Fwww.w3.org%2F2008%2F05%2Fcvswebrss.xsl&amp;xmlfile=http%3A%2F%2Fcgi.w3.org%2Fcgi-bin%2Ftidy%3FdocAddr%3Dhttp%253A%252F%252Fdev.w3.org%252Fcvsweb%252F2008%252Fws%252Ftt%252Fttaf1-dfxp.xml%26forceXML%3Don" dest="changelog.xml"/>
+      <get src="http://www.w3.org/2000/06/webdata/xslt?xslfile=http%3A%2F%2Fwww.w3.org%2F2008%2F05%2Fcvswebrss.xsl&amp;xmlfile=http%3A%2F%2Fcgi.w3.org%2Fcgi-bin%2Ftidy%3FdocAddr%3Dhttp%253A%252F%252Fdev.w3.org%252Fcvsweb%252F2008%252Fws%252Ftt%252Fttml11.xml%26forceXML%3Don" dest="changelog.xml"/>
     </target>
 
     <target name="generate" description="Generate the specification without updating changelog and acknowledgments sections"
@@ -203,7 +203,7 @@
     <target name="main" description="Generate the specification for a CVS commit"
 	    depends="changelog,validate-tt-specs,html">
 <!--	    depends="updateAcks,changelog,validate-tt-specs,html"> -->
-      <echo>ttaf1-dfxp.html is ready for CVS commit</echo>
+      <echo>ttml11.html is ready for CVS commit</echo>
       <echo>Use target "generate" to avoid regenerating changelog.xml and acknowledgments.xml</echo>
     </target>
 

--- a/ttml11/spec/rnc/ttaf1-dfxp-animation.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,30 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Animation Module .......................................
-# .......................................................................
-
-# set - discrete animation
-TTAF.set =
-  element set {
-    TTAF.set.attlist,
-    TTAF.set.content
-  }
-
-TTAF.set.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.Timed.attrib.class,
-  (TTAF.Styling.attrib.class |
-   TTAF.Styling.ForeignExtension.attrib+ )
-
-TTAF.set.content.extra = empty
-TTAF.set.content =
-  (TTAF.Metadata.class*,
-   TTAF.set.content.extra*)
-
-TTAF.Animation.extra = empty
-TTAF.Animation.class |=
-  TTAF.set |
-  TTAF.Animation.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-classes.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,29 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Class Declarations Module ..............................
-# .......................................................................
-
-# attribute group classes
-TTAF.Core.attrib.class = empty
-TTAF.Metadata.attrib.class = empty
-TTAF.Parameter.attrib.class = empty
-TTAF.RegionBinding.attrib.class = empty
-TTAF.StyleBinding.attrib.class = empty
-TTAF.Styled.attrib.class = empty
-TTAF.Styling.attrib.class = empty
-TTAF.Timed.attrib.class = empty
-TTAF.TimedContainer.attrib.class = empty
-TTAF.TimingInterval.attrib.class = empty
-
-# element group classes
-TTAF.Animation.class = empty
-TTAF.Block.class = empty
-TTAF.BlockNoDiv.class = empty
-TTAF.Inline.class = empty
-TTAF.InlineNoSpan.class = empty
-TTAF.MetadataNoAgent.class = empty
-TTAF.Metadata.class = empty
-TTAF.MetadataItems.class = empty
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-content.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,121 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Content Module .........................................
-# .......................................................................
-
-# body - content body
-TTAF.body =
-  element body {
-    TTAF.body.attlist,
-    TTAF.body.content
-  }
-
-TTAF.body.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.body.content.extra = empty
-TTAF.body.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Block.class | TTAF.body.content.extra)*)
-
-# div - division
-TTAF.div =
-  element div {
-    TTAF.div.attlist,
-    TTAF.div.content
-  }
-
-TTAF.div.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.div.content.extra = empty
-TTAF.div.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Block.class | TTAF.div.content.extra)*)
-
-# p - paragraph
-TTAF.p =
-  element p {
-    TTAF.p.attlist,
-    TTAF.p.content
-  }
-
-TTAF.p.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.p.content.extra = empty
-TTAF.p.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Inline.class |
-    TTAF.p.content.extra)*)
-
-# span - intra-paragraph inline span
-TTAF.span =
-  element span {
-    TTAF.span.attlist,
-    TTAF.span.content
-  }
-
-TTAF.span.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.span.content.extra = empty
-TTAF.span.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Inline.class |
-    TTAF.span.content.extra)*)
-
-# br - manual line break
-TTAF.br =
-  element br {
-    TTAF.br.attlist,
-    TTAF.br.content
-  }
-
-TTAF.br.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.Styled.attrib.class
-
-TTAF.br.content.extra = empty
-TTAF.br.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   TTAF.br.content.extra*)
-
-# Block.class
-TTAF.Block.extra = empty
-TTAF.BlockNoDiv.class |=
-  TTAF.p | TTAF.Block.extra
-TTAF.Block.class |=
-  TTAF.div | TTAF.BlockNoDiv.class
-
-# Inline.class
-TTAF.Inline.extra = empty
-TTAF.InlineNoSpan.class |=
-  text | TTAF.br | TTAF.Inline.extra
-TTAF.Inline.class |=
-  TTAF.span | TTAF.InlineNoSpan.class
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-core-attribs.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,34 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Core Attributes Module .................................
-# .......................................................................
-
-TTAF.id.attrib
-  = attribute xml:id { xsd:ID }?
-
-TTAF.lang.attrib
-  = attribute xml:lang { TTAF.LanguageCode.datatype }?
-
-TTAF.lang.required.attrib
-  = attribute xml:lang { TTAF.LanguageCode.datatype }
-
-TTAF.space.attrib
-  = attribute xml:space { TTAF.XMLSpace.datatype }?
-
-TTAF.Core.extra.attrib
-  = empty
-
-TTAF.Core.attrib.class &=
-  TTAF.id.attrib,
-  TTAF.lang.attrib,
-  TTAF.space.attrib,
-  TTAF.Core.extra.attrib
-
-TTAF.Core.required.attrib.class &=
-  TTAF.id.attrib,
-  TTAF.lang.required.attrib,
-  TTAF.space.attrib,
-  TTAF.Core.extra.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-datatypes.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,224 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Datatypes Module .......................................
-# .......................................................................
-
-TTAF.Alpha.datatype =
-  xsd:float { minInclusive = "0" maxInclusive = "1" }
-
-TTAF.Agent.datatype =
-  xsd:IDREFS
-
-TTAF.CellResolution.datatype =
-  string
-
-TTAF.ClockMode.datatype =
-  "local" |
-  "gps" |
-  "utc"
-
-TTAF.Color.datatype =
-  string
-
-TTAF.Direction.datatype =
-  "ltr" |
-  "rtl"
-
-TTAF.Display.datatype =
-  "auto" |
-  "none"
-
-TTAF.DisplayAlign.datatype =
-  "before" |
-  "center" |
-  "after"
-
-TTAF.DropMode.datatype =
-  "dropNTSC" |
-  "dropPAL" |
-  "nonDrop"
-
-TTAF.ExtensionDesignator.datatype =
-  TTAF.URI.datatype
-
-TTAF.ExtensionValue.datatype =
- "optional" |
- "required" |
- "use"
-
-TTAF.Extent.datatype =
-  string
-
-TTAF.FeatureDesignator.datatype =
-  TTAF.URI.datatype
-
-TTAF.FeatureValue.datatype =
- "optional" |
- "required" |
- "use"
-
-TTAF.FontFamily.datatype =
-  string
-
-TTAF.FontSize.datatype =
-  string
-
-TTAF.FontStyle.datatype =
-  "normal" |
-  "italic" |
-  "oblique"
-
-TTAF.FontWeight.datatype =
-  "normal" |
-  "bold"
-
-TTAF.FrameRate.datatype =
-  xsd:nonNegativeInteger
-
-TTAF.FrameRateMultiplier.datatype =
-  xsd:string { pattern = "\p{Nd}+\s+\p{Nd}+" }
-
-TTAF.LanguageCode.datatype =
-  xsd:NMTOKEN
-
-TTAF.LineHeight.datatype =
-  string
-
-TTAF.MarkerMode.datatype =
-  "continuous" |
-  "discontinuous"
-
-TTAF.MetadataAgentType.datatype =
-  "person" |
-  "character" |
-  "group" |
-  "organization" |
-  "other"
-
-TTAF.MetadataNameType.datatype =
-  "full" |
-  "family" |
-  "given" |
-  "alias" |
-  "other"
-
-TTAF.MetadataRoleBaseType.datatype =
-  "action" |
-  "caption" |
-  "description" |
-  "dialog" |
-  "expletive" |
-  "kinesic" |
-  "lyrics" |
-  "music" |
-  "narration" |
-  "quality" |
-  "sound" |
-  "source" |
-  "suppressed" |
-  "reproduction" |
-  "thought" |
-  "title" |
-  "transcription"
-
-TTAF.Opacity.datatype =
-  string
-
-TTAF.Origin.datatype =
-  string
-
-TTAF.Overflow.datatype =
-  "visible" |
-  "hidden" 
-
-TTAF.Padding.datatype =
-  string
-
-TTAF.PixelAspectRatio.datatype =
-  xsd:string { pattern = "\p{Nd}+\s+\p{Nd}+" }
-
-TTAF.Profile.datatype =
-  TTAF.URI.datatype
-
-TTAF.Role.datatype =
-  xsd:NMTOKENS
-
-TTAF.ShowBackground.datatype =
-  "always" |
-  "whenActive"
-
-TTAF.SubFrameRate.datatype =
-  xsd:positiveInteger
-
-TTAF.TextAlign.datatype =
-  "left" |
-  "center" |
-  "right" |
-  "start" |
-  "end"
-
-TTAF.TextDecoration.datatype =
-  "none" |
-  "underline" |
-  "noUnderline" |
-  "overline" |
-  "noOverline" |
-  "lineThrough" |
-  "noLineThrough"
-
-TTAF.TextOutline.datatype =
-  string
-
-TTAF.TickRate.datatype =
-  xsd:positiveInteger
-
-TTAF.TimeBase.datatype =
-  "media" |
-  "smpte" |
-  "clock"
-
-TTAF.TimeContainer.datatype =
-  "par" |
-  "seq"
-
-TTAF.TimeCoordinate.datatype =
-  string
-
-TTAF.TimeDuration.datatype =
-  string
-
-TTAF.URI.datatype =
-  xsd:anyURI
-
-TTAF.UnicodeBidi.datatype =
-  "normal" |
-  "embed" |
-  "bidiOverride"
-
-TTAF.Visibility.datatype =
-  "hidden" |
-  "visible"
-
-TTAF.WrapOption.datatype =
-  "wrap" |
-  "noWrap"
-
-TTAF.WritingMode.datatype =
-  "lrtb" |
-  "rltb" |
-  "tbrl" |
-  "tblr" |
-  "lr" |
-  "rl" |
-  "tb"
-
-TTAF.XMLSpace.datatype =
-  "default" |
-  "preserve"
-
-TTAF.ZIndex.datatype =
-  string
-  
-# .......................................................................
-# .......................................................................
-# .......................................................................
-

--- a/ttml11/spec/rnc/ttaf1-dfxp-document.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,22 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Document Module ........................................
-# .......................................................................
-
-## tt - generic top-level document element type
-TTAF.tt =
-  element tt {
-    TTAF.tt.attlist,
-    TTAF.tt.content
-  }
-
-TTAF.tt.attlist &=
-  TTAF.Core.required.attrib.class,
-  TTAF.Parameter.attrib.class,
-  TTAF.extent.attrib
-
-TTAF.tt.content =
-  (TTAF.head?, TTAF.body?)
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-head.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,25 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Header Module ..........................................
-# .......................................................................
-
-# head - generic header
-TTAF.head =
-  element head {
-    TTAF.head.attlist,
-    TTAF.head.content
-  }
-
-TTAF.head.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.head.content.extra = empty
-TTAF.head.content =
-  (TTAF.Metadata.class*,
-   TTAF.Parameters.class*,
-   TTAF.styling?,
-   TTAF.layout?,
-   TTAF.head.content.extra*)
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-layout.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,52 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Layout Module ..........................................
-# .......................................................................
-
-# region reference attribute; must reference /head/layout/region
-TTAF.region.attrib
-  = attribute region { xsd:IDREF }?
-
-# region binding attribute class
-TTAF.RegionBinding.attrib.class &=
-  TTAF.region.attrib
-
-# layout - generic layout container
-TTAF.layout =
-  element layout {
-    TTAF.layout.attlist,
-    TTAF.layout.content
-  }
-
-TTAF.layout.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.layout.content.extra = empty
-TTAF.layout.content =
-  (TTAF.Metadata.class*,
-   TTAF.layout.region*,
-   TTAF.layout.content.extra*)
-
-# region - region declaration
-TTAF.layout.region =
-  element region {
-    TTAF.layout.region.attlist,
-    TTAF.layout.region.content
-  }
-
-TTAF.layout.region.attlist &=
-  TTAF.Core.attrib.class,
-  TTAF.TimedContainer.attrib.class,
-  TTAF.style.attrib,
-  (TTAF.Styling.attrib.class |
-   TTAF.Styling.ForeignExtension.attrib+ )
-
-TTAF.layout.region.content.extra = empty
-TTAF.layout.region.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   TTAF.styling.style*,
-   TTAF.layout.region.content.extra*)
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-metadata-attribs.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,24 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Metadata Attributes Module ..............................
-# .......................................................................
-
-namespace tt = "http://www.w3.org/ns/ttml"
-namespace ttm = "http://www.w3.org/ns/ttml#metadata"
-namespace local = ""
-
-# Standard Metadata Attributes
-
-TTAF.agent.attrib
-  = attribute ttm:agent { TTAF.Agent.datatype }?
-TTAF.role.attrib
-  = attribute ttm:role { TTAF.Role.datatype }?
-
-# Metadata Attribute Class
-
-TTAF.Metadata.attrib.class &=
-  TTAF.agent.attrib,
-  TTAF.role.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-metadata-items.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,102 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Metadata Items Module ......................................
-# .......................................................................
-
-namespace ttm = "http://www.w3.org/ns/ttml#metadata"
-
-## actor - specifies actor
-TTAF.meta.actor =
-  element ttm:actor {
-    TTAF.meta.actor.attlist,
-    TTAF.meta.actor.content
-  }
-
-TTAF.meta.actor.attlist &=
-  TTAF.Core.attrib.class,
-  attribute agent { xsd:IDREF }
-
-TTAF.meta.actor.content.extra = empty
-TTAF.meta.actor.content = empty
-
-## agent - specifies agent
-TTAF.meta.agent =
-  element ttm:agent {
-    TTAF.meta.agent.attlist,
-    TTAF.meta.agent.content
-  }
-
-TTAF.meta.agent.attlist &=
-  TTAF.Core.attrib.class,
-  attribute type { TTAF.MetadataAgentType.datatype }
-
-TTAF.meta.agent.content.extra = empty
-TTAF.meta.agent.content =
-  (TTAF.meta.name*,
-   TTAF.meta.actor?,
-   TTAF.meta.agent.content.extra*)
-
-## copyright - specifies copyright statement
-TTAF.meta.copyright =
-  element ttm:copyright {
-    TTAF.meta.copyright.attlist,
-    TTAF.meta.copyright.content
-  }
-
-TTAF.meta.copyright.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.meta.copyright.content.extra = empty
-TTAF.meta.copyright.content = text
-
-## desc - specifies description
-TTAF.meta.desc =
-  element ttm:desc {
-    TTAF.meta.desc.attlist,
-    TTAF.meta.desc.content
-  }
-
-TTAF.meta.desc.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.meta.desc.content.extra = empty
-TTAF.meta.desc.content = text
-
-## name - specifies name
-TTAF.meta.name =
-  element ttm:name {
-    TTAF.meta.name.attlist,
-    TTAF.meta.name.content
-  }
-
-TTAF.meta.name.attlist &=
-  TTAF.Core.attrib.class,
-  attribute type { TTAF.MetadataNameType.datatype }
-
-TTAF.meta.name.content.extra = empty
-TTAF.meta.name.content = text
-
-## title - describes title
-TTAF.meta.title =
-  element ttm:title {
-    TTAF.meta.title.attlist,
-    TTAF.meta.title.content
-  }
-
-TTAF.meta.title.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.meta.title.content.extra = empty
-TTAF.meta.title.content = text
-
-## MetadataItems.class
-TTAF.MetadataItems.extra = empty
-TTAF.MetadataItems.class |=
-  TTAF.meta.agent |
-  TTAF.meta.copyright |
-  TTAF.meta.desc |
-  TTAF.meta.title |
-  TTAF.MetadataItems.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-metadata.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,40 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Metadata Module ........................................
-# .......................................................................
-
-# namespace prefix bindings
-namespace tt = "http://www.w3.org/ns/ttml"
-namespace ttm = "http://www.w3.org/ns/ttml#metadata"
-namespace local = ""
-
-# meta - generic metadata
-TTAF.metadata =
-  element metadata {
-    TTAF.metadata.attlist,
-    TTAF.metadata.content
-  }
-
-TTAF.metadata.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.External.class =
-  element * - ( tt:* | ttm:* ) {
-    ( attribute * - ( xml:id ) { text }
-      | text
-      | TTAF.External.class
-    )*
-  }
-
-TTAF.metadata.content.extra = empty
-TTAF.metadata.content =
-  (TTAF.MetadataItems.class |
-   TTAF.External.class |
-   TTAF.metadata.content.extra)*
-
-TTAF.Metadata.class |=
-  TTAF.MetadataItems.class |
-  TTAF.metadata
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-parameter-attribs.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,49 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Parameter Attributes Module ............................
-# .......................................................................
-
-namespace ttp = "http://www.w3.org/ns/ttml#parameter"
-
-# Standard Metadata Attributes
-
-TTAF.cellResolution.attrib
-  = attribute ttp:cellResolution { TTAF.CellResolution.datatype }?
-TTAF.clockMode.attrib
-  = attribute ttp:clockMode { TTAF.ClockMode.datatype }?
-TTAF.dropMode.attrib
-  = attribute ttp:dropMode { TTAF.DropMode.datatype }?
-TTAF.frameRate.attrib
-  = attribute ttp:frameRate { TTAF.FrameRate.datatype }?
-TTAF.frameRateMultiplier.attrib
-  = attribute ttp:frameRateMultiplier { TTAF.FrameRateMultiplier.datatype }?
-TTAF.markerMode.attrib
-  = attribute ttp:markerMode { TTAF.MarkerMode.datatype }?
-TTAF.profile.attrib
-  = attribute ttp:profile { TTAF.Profile.datatype }?
-TTAF.pixelAspectRatio.attrib
-  = attribute ttp:pixelAspectRatio { TTAF.PixelAspectRatio.datatype }?
-TTAF.subFrameRate.attrib
-  = attribute ttp:subFrameRate { TTAF.SubFrameRate.datatype }?
-TTAF.tickRate.attrib
-  = attribute ttp:tickRate { TTAF.TickRate.datatype }?
-TTAF.timeBase.attrib
-  = attribute ttp:timeBase { TTAF.TimeBase.datatype }?
-
-# Parameter Attribute Class
-
-TTAF.Parameter.attrib.class &=
-  TTAF.cellResolution.attrib,
-  TTAF.clockMode.attrib,
-  TTAF.dropMode.attrib,
-  TTAF.frameRate.attrib,
-  TTAF.frameRateMultiplier.attrib,
-  TTAF.markerMode.attrib,
-  TTAF.pixelAspectRatio.attrib,
-  TTAF.profile.attrib,
-  TTAF.subFrameRate.attrib,
-  TTAF.tickRate.attrib,
-  TTAF.timeBase.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-parameter-items.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,95 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Parameter Items Module .................................
-# .......................................................................
-
-namespace ttp = "http://www.w3.org/ns/ttml#parameter"
-
-# profile - profile definition or use declaration
-TTAF.parameters.profile =
-  element ttp:profile {
-    TTAF.parameters.profile.attlist,
-    TTAF.parameters.profile.content
-  }
-
-TTAF.parameters.profile.attlist &=
-  TTAF.id.attrib,
-  attribute use { TTAF.Profile.datatype }?
-
-TTAF.parameters.profile.content.extra = empty
-TTAF.parameters.profile.content =
-  (TTAF.Metadata.class*,
-   TTAF.parameters.features*,
-   TTAF.parameters.extensions*,
-   TTAF.parameters.profile.content.extra*)
-
-# features - container for feature elements
-TTAF.parameters.features =
-  element ttp:features {
-    TTAF.parameters.features.attlist,
-    TTAF.parameters.features.content
-  }
-
-TTAF.parameters.features.attlist &=
-  TTAF.id.attrib,
-  attribute xml:base { TTAF.URI.datatype }?
-
-TTAF.parameters.features.content.extra = empty
-TTAF.parameters.features.content =
-  (TTAF.Metadata.class*,
-   TTAF.parameters.feature*,
-   TTAF.parameters.features.content.extra*)
-
-# feature - feature requirements declaration
-TTAF.parameters.feature =
-  element ttp:feature {
-    TTAF.parameters.feature.attlist,
-    TTAF.parameters.feature.content
-  }
-
-TTAF.parameters.feature.attlist =
-  TTAF.id.attrib,
-  attribute value { TTAF.FeatureValue.datatype }?
-
-TTAF.parameters.feature.content =
-  TTAF.FeatureDesignator.datatype
-
-# extensions - container for extension elements
-TTAF.parameters.extensions =
-  element ttp:extensions {
-    TTAF.parameters.extensions.attlist,
-    TTAF.parameters.extensions.content
-  }
-
-TTAF.parameters.extensions.attlist &=
-  TTAF.id.attrib,
-  attribute xml:base { TTAF.URI.datatype }?
-
-TTAF.parameters.extensions.content.extra = empty
-TTAF.parameters.extensions.content =
-  (TTAF.Metadata.class*,
-   TTAF.parameters.extension*,
-   TTAF.parameters.extensions.content.extra*)
-
-# extension - extension requirements declaration
-TTAF.parameters.extension =
-  element ttp:extension {
-    TTAF.parameters.extension.attlist,
-    TTAF.parameters.extension.content
-  }
-
-TTAF.parameters.extension.attlist =
-  TTAF.id.attrib,
-  attribute value { TTAF.ExtensionValue.datatype }?
-
-TTAF.parameters.extension.content =
-  TTAF.ExtensionDesignator.datatype
-
-## ParameterItems.class
-TTAF.ParameterItems.extra = empty
-TTAF.ParameterItems.class |=
-  TTAF.parameters.profile |
-  TTAF.ParameterItems.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-parameters.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,10 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Parameters Module ......................................
-# .......................................................................
-
-TTAF.Parameters.class |=
-  TTAF.ParameterItems.class
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-styling-attribs.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,108 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Styling Attributes Module ..............................
-# .......................................................................
-
-namespace tt = "http://www.w3.org/ns/ttml"
-namespace tts = "http://www.w3.org/ns/ttml#styling"
-namespace local = ""
-
-# Standard Style Attributes
-
-TTAF.backgroundColor.attrib
-  = attribute tts:backgroundColor { TTAF.Color.datatype }?
-TTAF.color.attrib
-  = attribute tts:color { TTAF.Color.datatype }?
-TTAF.direction.attrib
-  = attribute tts:direction { TTAF.Direction.datatype }?
-TTAF.display.attrib
-  = attribute tts:display { TTAF.Display.datatype }?
-TTAF.displayAlign.attrib
-  = attribute tts:displayAlign { TTAF.DisplayAlign.datatype }?
-TTAF.extent.attrib
-  = attribute tts:extent { TTAF.Extent.datatype }?
-TTAF.fontFamily.attrib
-  = attribute tts:fontFamily { TTAF.FontFamily.datatype }?
-TTAF.fontSize.attrib
-  = attribute tts:fontSize { TTAF.FontSize.datatype }?
-TTAF.fontStyle.attrib
-  = attribute tts:fontStyle { TTAF.FontStyle.datatype }?
-TTAF.fontWeight.attrib
-  = attribute tts:fontWeight { TTAF.FontWeight.datatype }?
-TTAF.lineHeight.attrib
-  = attribute tts:lineHeight { TTAF.LineHeight.datatype }?
-TTAF.opacity.attrib
-  = attribute tts:opacity { TTAF.Opacity.datatype }?
-TTAF.origin.attrib
-  = attribute tts:origin { TTAF.Origin.datatype }?
-TTAF.overflow.attrib
-  = attribute tts:overflow { TTAF.Overflow.datatype }?
-TTAF.padding.attrib
-  = attribute tts:padding { TTAF.Padding.datatype }?
-TTAF.showBackground.attrib
-  = attribute tts:showBackground { TTAF.ShowBackground.datatype }?
-TTAF.textAlign.attrib
-  = attribute tts:textAlign { TTAF.TextAlign.datatype }?
-TTAF.textDecoration.attrib
-  = attribute tts:textDecoration { TTAF.TextDecoration.datatype }?
-TTAF.textOutline.attrib
-  = attribute tts:textOutline { TTAF.TextOutline.datatype }?
-TTAF.unicodeBidi.attrib
-  = attribute tts:unicodeBidi { TTAF.UnicodeBidi.datatype }?
-TTAF.visibility.attrib
-  = attribute tts:visibility { TTAF.Visibility.datatype }?
-TTAF.wrapOption.attrib
-  = attribute tts:wrapOption { TTAF.WrapOption.datatype }?
-TTAF.writingMode.attrib
-  = attribute tts:writingMode { TTAF.WritingMode.datatype }?
-TTAF.zIndex.attrib
-  = attribute tts:zIndex { TTAF.ZIndex.datatype }?
-
-# Extension Style Attributes
-
-TTAF.Styling.ForeignExtension.attrib =
-  attribute * - ( tt:* | tts:* | xml:* | local:* ) { text }
-
-# Styling Attribute Class
-
-TTAF.Styling.attrib.class &=
-  TTAF.backgroundColor.attrib,
-  TTAF.color.attrib,
-  TTAF.direction.attrib,
-  TTAF.display.attrib,
-  TTAF.displayAlign.attrib,
-  TTAF.extent.attrib,
-  TTAF.fontFamily.attrib,
-  TTAF.fontSize.attrib,
-  TTAF.fontStyle.attrib,
-  TTAF.fontWeight.attrib,
-  TTAF.lineHeight.attrib,
-  TTAF.opacity.attrib,
-  TTAF.origin.attrib,
-  TTAF.overflow.attrib,
-  TTAF.padding.attrib,
-  TTAF.showBackground.attrib,
-  TTAF.textAlign.attrib,
-  TTAF.textDecoration.attrib,
-  TTAF.textOutline.attrib,
-  TTAF.unicodeBidi.attrib,
-  TTAF.visibility.attrib,
-  TTAF.wrapOption.attrib,
-  TTAF.writingMode.attrib,
-  TTAF.zIndex.attrib
-
-# Style Binding Attribute Class
-
-TTAF.StyleBinding.attrib.class &=
-  TTAF.style.attrib
-
-# Styled Content Attribute Class
-
-TTAF.Styled.extra.attrib = empty
-TTAF.Styled.attrib.class &=
-  TTAF.Styling.attrib.class,
-  TTAF.StyleBinding.attrib.class,
-  TTAF.Styled.extra.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp-styling.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,50 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Styling Module .........................................
-# .......................................................................
-
-# style reference attribute; must reference /tt/head/styling/style
-TTAF.style.attrib
-  = attribute style { xsd:IDREFS }?
-
-# styling - generic styling container
-TTAF.styling =
-  element styling {
-    TTAF.styling.attlist,
-    TTAF.styling.content
-  }
-
-TTAF.styling.attlist &=
-  TTAF.Core.attrib.class
-
-TTAF.styling.content.extra = empty
-TTAF.styling.content =
-  (TTAF.Metadata.class*,
-   TTAF.styling.defs.class*,
-   TTAF.styling.content.extra*)
-
-# style - style declaration
-TTAF.styling.style =
-  element style {
-    TTAF.styling.style.attlist,
-    TTAF.styling.style.content
-  }
-
-TTAF.styling.style.attlist =
-  TTAF.Core.attrib.class,
-  TTAF.style.attrib,
-  (TTAF.Styling.attrib.class |
-   TTAF.Styling.ForeignExtension.attrib+ )
-
-TTAF.styling.style.content.extra = empty
-TTAF.styling.style.content =
-  (TTAF.styling.style.content.extra)*
-
-# style definitions class
-TTAF.styling.defs.extra = empty
-TTAF.styling.defs.class = 
-  TTAF.styling.style
-  | TTAF.styling.defs.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
\ No newline at end of file

--- a/ttml11/spec/rnc/ttaf1-dfxp-timing-attribs.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,49 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 DFXP Timing Attributes Module ...............................
-# .......................................................................
-
-# Timing Attributes
-
-TTAF.timing.begin.attrib
-  = attribute begin { TTAF.TimeCoordinate.datatype }?
-TTAF.timing.dur.attrib
-  = attribute dur { TTAF.TimeDuration.datatype }?
-TTAF.timing.end.attrib
-  = attribute end { TTAF.TimeCoordinate.datatype }?
-TTAF.timing.timeContainer.attrib
-  = attribute timeContainer { TTAF.TimeContainer.datatype }?
-
-# Timing Interval Attribute class
-
-TTAF.TimingInterval.extra.attrib = empty
-TTAF.TimingInterval.attrib.class &=
-  TTAF.timing.begin.attrib,
-  TTAF.timing.dur.attrib,
-  TTAF.timing.end.attrib,
-  TTAF.TimingInterval.extra.attrib
-
-# Timing Container Attribute class
-
-TTAF.TimingContainer.extra.attrib = empty
-TTAF.TimingContainer.attrib.class &=
-  TTAF.timing.timeContainer.attrib,
-  TTAF.TimingContainer.extra.attrib
-
-# Timed Content Attribute Class
-
-TTAF.Timed.extra.attrib = empty
-TTAF.Timed.attrib.class &=
-  TTAF.TimingInterval.attrib.class,
-  TTAF.Timed.extra.attrib
-
-# Timed Content Container Attribute Class
-
-TTAF.TimedContainer.extra.attrib = empty
-TTAF.TimedContainer.attrib.class &=
-  TTAF.Timed.attrib.class,
-  TTAF.TimingContainer.attrib.class,
-  TTAF.TimedContainer.extra.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- a/ttml11/spec/rnc/ttaf1-dfxp.rnc	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,31 +0,0 @@
-# .......................................................................
-# TT-AF 1.0 Distribution Format Exchange Profile (DFXP) Schema ..........
-# .......................................................................
-
-# default namespace
-default namespace tt = "http://www.w3.org/ns/ttml"
-
-# generic tt modules
-include "ttaf1-dfxp-datatypes.rnc"
-include "ttaf1-dfxp-classes.rnc"
-include "ttaf1-dfxp-core-attribs.rnc"
-include "ttaf1-dfxp-parameter-attribs.rnc"
-include "ttaf1-dfxp-metadata-attribs.rnc"
-include "ttaf1-dfxp-styling-attribs.rnc"
-include "ttaf1-dfxp-timing-attribs.rnc"
-include "ttaf1-dfxp-parameter-items.rnc"
-include "ttaf1-dfxp-parameters.rnc"
-include "ttaf1-dfxp-metadata-items.rnc"
-include "ttaf1-dfxp-metadata.rnc"
-include "ttaf1-dfxp-styling.rnc"
-include "ttaf1-dfxp-animation.rnc"
-include "ttaf1-dfxp-layout.rnc"
-include "ttaf1-dfxp-content.rnc"
-include "ttaf1-dfxp-head.rnc"
-include "ttaf1-dfxp-document.rnc"
-
-start = TTAF.tt | TTAF.parameters.profile
-
-# .......................................................................
-# .......................................................................
-# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-animation.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,30 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Animation Module .......................................
+# .......................................................................
+
+# set - discrete animation
+TTAF.set =
+  element set {
+    TTAF.set.attlist,
+    TTAF.set.content
+  }
+
+TTAF.set.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.Timed.attrib.class,
+  (TTAF.Styling.attrib.class |
+   TTAF.Styling.ForeignExtension.attrib+ )
+
+TTAF.set.content.extra = empty
+TTAF.set.content =
+  (TTAF.Metadata.class*,
+   TTAF.set.content.extra*)
+
+TTAF.Animation.extra = empty
+TTAF.Animation.class |=
+  TTAF.set |
+  TTAF.Animation.extra
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-classes.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,29 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Class Declarations Module ..............................
+# .......................................................................
+
+# attribute group classes
+TTAF.Core.attrib.class = empty
+TTAF.Metadata.attrib.class = empty
+TTAF.Parameter.attrib.class = empty
+TTAF.RegionBinding.attrib.class = empty
+TTAF.StyleBinding.attrib.class = empty
+TTAF.Styled.attrib.class = empty
+TTAF.Styling.attrib.class = empty
+TTAF.Timed.attrib.class = empty
+TTAF.TimedContainer.attrib.class = empty
+TTAF.TimingInterval.attrib.class = empty
+
+# element group classes
+TTAF.Animation.class = empty
+TTAF.Block.class = empty
+TTAF.BlockNoDiv.class = empty
+TTAF.Inline.class = empty
+TTAF.InlineNoSpan.class = empty
+TTAF.MetadataNoAgent.class = empty
+TTAF.Metadata.class = empty
+TTAF.MetadataItems.class = empty
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-content.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,121 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Content Module .........................................
+# .......................................................................
+
+# body - content body
+TTAF.body =
+  element body {
+    TTAF.body.attlist,
+    TTAF.body.content
+  }
+
+TTAF.body.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.Metadata.attrib.class,
+  TTAF.RegionBinding.attrib.class,
+  TTAF.Styled.attrib.class,
+  TTAF.TimedContainer.attrib.class
+
+TTAF.body.content.extra = empty
+TTAF.body.content =
+  (TTAF.Metadata.class*,
+   TTAF.Animation.class*,
+   (TTAF.Block.class | TTAF.body.content.extra)*)
+
+# div - division
+TTAF.div =
+  element div {
+    TTAF.div.attlist,
+    TTAF.div.content
+  }
+
+TTAF.div.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.Metadata.attrib.class,
+  TTAF.RegionBinding.attrib.class,
+  TTAF.Styled.attrib.class,
+  TTAF.TimedContainer.attrib.class
+
+TTAF.div.content.extra = empty
+TTAF.div.content =
+  (TTAF.Metadata.class*,
+   TTAF.Animation.class*,
+   (TTAF.Block.class | TTAF.div.content.extra)*)
+
+# p - paragraph
+TTAF.p =
+  element p {
+    TTAF.p.attlist,
+    TTAF.p.content
+  }
+
+TTAF.p.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.Metadata.attrib.class,
+  TTAF.RegionBinding.attrib.class,
+  TTAF.Styled.attrib.class,
+  TTAF.TimedContainer.attrib.class
+
+TTAF.p.content.extra = empty
+TTAF.p.content =
+  (TTAF.Metadata.class*,
+   TTAF.Animation.class*,
+   (TTAF.Inline.class |
+    TTAF.p.content.extra)*)
+
+# span - intra-paragraph inline span
+TTAF.span =
+  element span {
+    TTAF.span.attlist,
+    TTAF.span.content
+  }
+
+TTAF.span.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.Metadata.attrib.class,
+  TTAF.RegionBinding.attrib.class,
+  TTAF.Styled.attrib.class,
+  TTAF.TimedContainer.attrib.class
+
+TTAF.span.content.extra = empty
+TTAF.span.content =
+  (TTAF.Metadata.class*,
+   TTAF.Animation.class*,
+   (TTAF.Inline.class |
+    TTAF.span.content.extra)*)
+
+# br - manual line break
+TTAF.br =
+  element br {
+    TTAF.br.attlist,
+    TTAF.br.content
+  }
+
+TTAF.br.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.Metadata.attrib.class,
+  TTAF.Styled.attrib.class
+
+TTAF.br.content.extra = empty
+TTAF.br.content =
+  (TTAF.Metadata.class*,
+   TTAF.Animation.class*,
+   TTAF.br.content.extra*)
+
+# Block.class
+TTAF.Block.extra = empty
+TTAF.BlockNoDiv.class |=
+  TTAF.p | TTAF.Block.extra
+TTAF.Block.class |=
+  TTAF.div | TTAF.BlockNoDiv.class
+
+# Inline.class
+TTAF.Inline.extra = empty
+TTAF.InlineNoSpan.class |=
+  text | TTAF.br | TTAF.Inline.extra
+TTAF.Inline.class |=
+  TTAF.span | TTAF.InlineNoSpan.class
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-core-attribs.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,34 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Core Attributes Module .................................
+# .......................................................................
+
+TTAF.id.attrib
+  = attribute xml:id { xsd:ID }?
+
+TTAF.lang.attrib
+  = attribute xml:lang { TTAF.LanguageCode.datatype }?
+
+TTAF.lang.required.attrib
+  = attribute xml:lang { TTAF.LanguageCode.datatype }
+
+TTAF.space.attrib
+  = attribute xml:space { TTAF.XMLSpace.datatype }?
+
+TTAF.Core.extra.attrib
+  = empty
+
+TTAF.Core.attrib.class &=
+  TTAF.id.attrib,
+  TTAF.lang.attrib,
+  TTAF.space.attrib,
+  TTAF.Core.extra.attrib
+
+TTAF.Core.required.attrib.class &=
+  TTAF.id.attrib,
+  TTAF.lang.required.attrib,
+  TTAF.space.attrib,
+  TTAF.Core.extra.attrib
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-datatypes.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,224 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Datatypes Module .......................................
+# .......................................................................
+
+TTAF.Alpha.datatype =
+  xsd:float { minInclusive = "0" maxInclusive = "1" }
+
+TTAF.Agent.datatype =
+  xsd:IDREFS
+
+TTAF.CellResolution.datatype =
+  string
+
+TTAF.ClockMode.datatype =
+  "local" |
+  "gps" |
+  "utc"
+
+TTAF.Color.datatype =
+  string
+
+TTAF.Direction.datatype =
+  "ltr" |
+  "rtl"
+
+TTAF.Display.datatype =
+  "auto" |
+  "none"
+
+TTAF.DisplayAlign.datatype =
+  "before" |
+  "center" |
+  "after"
+
+TTAF.DropMode.datatype =
+  "dropNTSC" |
+  "dropPAL" |
+  "nonDrop"
+
+TTAF.ExtensionDesignator.datatype =
+  TTAF.URI.datatype
+
+TTAF.ExtensionValue.datatype =
+ "optional" |
+ "required" |
+ "use"
+
+TTAF.Extent.datatype =
+  string
+
+TTAF.FeatureDesignator.datatype =
+  TTAF.URI.datatype
+
+TTAF.FeatureValue.datatype =
+ "optional" |
+ "required" |
+ "use"
+
+TTAF.FontFamily.datatype =
+  string
+
+TTAF.FontSize.datatype =
+  string
+
+TTAF.FontStyle.datatype =
+  "normal" |
+  "italic" |
+  "oblique"
+
+TTAF.FontWeight.datatype =
+  "normal" |
+  "bold"
+
+TTAF.FrameRate.datatype =
+  xsd:nonNegativeInteger
+
+TTAF.FrameRateMultiplier.datatype =
+  xsd:string { pattern = "\p{Nd}+\s+\p{Nd}+" }
+
+TTAF.LanguageCode.datatype =
+  xsd:NMTOKEN
+
+TTAF.LineHeight.datatype =
+  string
+
+TTAF.MarkerMode.datatype =
+  "continuous" |
+  "discontinuous"
+
+TTAF.MetadataAgentType.datatype =
+  "person" |
+  "character" |
+  "group" |
+  "organization" |
+  "other"
+
+TTAF.MetadataNameType.datatype =
+  "full" |
+  "family" |
+  "given" |
+  "alias" |
+  "other"
+
+TTAF.MetadataRoleBaseType.datatype =
+  "action" |
+  "caption" |
+  "description" |
+  "dialog" |
+  "expletive" |
+  "kinesic" |
+  "lyrics" |
+  "music" |
+  "narration" |
+  "quality" |
+  "sound" |
+  "source" |
+  "suppressed" |
+  "reproduction" |
+  "thought" |
+  "title" |
+  "transcription"
+
+TTAF.Opacity.datatype =
+  string
+
+TTAF.Origin.datatype =
+  string
+
+TTAF.Overflow.datatype =
+  "visible" |
+  "hidden" 
+
+TTAF.Padding.datatype =
+  string
+
+TTAF.PixelAspectRatio.datatype =
+  xsd:string { pattern = "\p{Nd}+\s+\p{Nd}+" }
+
+TTAF.Profile.datatype =
+  TTAF.URI.datatype
+
+TTAF.Role.datatype =
+  xsd:NMTOKENS
+
+TTAF.ShowBackground.datatype =
+  "always" |
+  "whenActive"
+
+TTAF.SubFrameRate.datatype =
+  xsd:positiveInteger
+
+TTAF.TextAlign.datatype =
+  "left" |
+  "center" |
+  "right" |
+  "start" |
+  "end"
+
+TTAF.TextDecoration.datatype =
+  "none" |
+  "underline" |
+  "noUnderline" |
+  "overline" |
+  "noOverline" |
+  "lineThrough" |
+  "noLineThrough"
+
+TTAF.TextOutline.datatype =
+  string
+
+TTAF.TickRate.datatype =
+  xsd:positiveInteger
+
+TTAF.TimeBase.datatype =
+  "media" |
+  "smpte" |
+  "clock"
+
+TTAF.TimeContainer.datatype =
+  "par" |
+  "seq"
+
+TTAF.TimeCoordinate.datatype =
+  string
+
+TTAF.TimeDuration.datatype =
+  string
+
+TTAF.URI.datatype =
+  xsd:anyURI
+
+TTAF.UnicodeBidi.datatype =
+  "normal" |
+  "embed" |
+  "bidiOverride"
+
+TTAF.Visibility.datatype =
+  "hidden" |
+  "visible"
+
+TTAF.WrapOption.datatype =
+  "wrap" |
+  "noWrap"
+
+TTAF.WritingMode.datatype =
+  "lrtb" |
+  "rltb" |
+  "tbrl" |
+  "tblr" |
+  "lr" |
+  "rl" |
+  "tb"
+
+TTAF.XMLSpace.datatype =
+  "default" |
+  "preserve"
+
+TTAF.ZIndex.datatype =
+  string
+  
+# .......................................................................
+# .......................................................................
+# .......................................................................
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-document.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,22 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Document Module ........................................
+# .......................................................................
+
+## tt - generic top-level document element type
+TTAF.tt =
+  element tt {
+    TTAF.tt.attlist,
+    TTAF.tt.content
+  }
+
+TTAF.tt.attlist &=
+  TTAF.Core.required.attrib.class,
+  TTAF.Parameter.attrib.class,
+  TTAF.extent.attrib
+
+TTAF.tt.content =
+  (TTAF.head?, TTAF.body?)
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-head.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,25 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Header Module ..........................................
+# .......................................................................
+
+# head - generic header
+TTAF.head =
+  element head {
+    TTAF.head.attlist,
+    TTAF.head.content
+  }
+
+TTAF.head.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.head.content.extra = empty
+TTAF.head.content =
+  (TTAF.Metadata.class*,
+   TTAF.Parameters.class*,
+   TTAF.styling?,
+   TTAF.layout?,
+   TTAF.head.content.extra*)
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-layout.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,52 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Layout Module ..........................................
+# .......................................................................
+
+# region reference attribute; must reference /head/layout/region
+TTAF.region.attrib
+  = attribute region { xsd:IDREF }?
+
+# region binding attribute class
+TTAF.RegionBinding.attrib.class &=
+  TTAF.region.attrib
+
+# layout - generic layout container
+TTAF.layout =
+  element layout {
+    TTAF.layout.attlist,
+    TTAF.layout.content
+  }
+
+TTAF.layout.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.layout.content.extra = empty
+TTAF.layout.content =
+  (TTAF.Metadata.class*,
+   TTAF.layout.region*,
+   TTAF.layout.content.extra*)
+
+# region - region declaration
+TTAF.layout.region =
+  element region {
+    TTAF.layout.region.attlist,
+    TTAF.layout.region.content
+  }
+
+TTAF.layout.region.attlist &=
+  TTAF.Core.attrib.class,
+  TTAF.TimedContainer.attrib.class,
+  TTAF.style.attrib,
+  (TTAF.Styling.attrib.class |
+   TTAF.Styling.ForeignExtension.attrib+ )
+
+TTAF.layout.region.content.extra = empty
+TTAF.layout.region.content =
+  (TTAF.Metadata.class*,
+   TTAF.Animation.class*,
+   TTAF.styling.style*,
+   TTAF.layout.region.content.extra*)
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-metadata-attribs.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,24 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Metadata Attributes Module ..............................
+# .......................................................................
+
+namespace tt = "http://www.w3.org/ns/ttml"
+namespace ttm = "http://www.w3.org/ns/ttml#metadata"
+namespace local = ""
+
+# Standard Metadata Attributes
+
+TTAF.agent.attrib
+  = attribute ttm:agent { TTAF.Agent.datatype }?
+TTAF.role.attrib
+  = attribute ttm:role { TTAF.Role.datatype }?
+
+# Metadata Attribute Class
+
+TTAF.Metadata.attrib.class &=
+  TTAF.agent.attrib,
+  TTAF.role.attrib
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-metadata-items.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,102 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Metadata Items Module ......................................
+# .......................................................................
+
+namespace ttm = "http://www.w3.org/ns/ttml#metadata"
+
+## actor - specifies actor
+TTAF.meta.actor =
+  element ttm:actor {
+    TTAF.meta.actor.attlist,
+    TTAF.meta.actor.content
+  }
+
+TTAF.meta.actor.attlist &=
+  TTAF.Core.attrib.class,
+  attribute agent { xsd:IDREF }
+
+TTAF.meta.actor.content.extra = empty
+TTAF.meta.actor.content = empty
+
+## agent - specifies agent
+TTAF.meta.agent =
+  element ttm:agent {
+    TTAF.meta.agent.attlist,
+    TTAF.meta.agent.content
+  }
+
+TTAF.meta.agent.attlist &=
+  TTAF.Core.attrib.class,
+  attribute type { TTAF.MetadataAgentType.datatype }
+
+TTAF.meta.agent.content.extra = empty
+TTAF.meta.agent.content =
+  (TTAF.meta.name*,
+   TTAF.meta.actor?,
+   TTAF.meta.agent.content.extra*)
+
+## copyright - specifies copyright statement
+TTAF.meta.copyright =
+  element ttm:copyright {
+    TTAF.meta.copyright.attlist,
+    TTAF.meta.copyright.content
+  }
+
+TTAF.meta.copyright.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.meta.copyright.content.extra = empty
+TTAF.meta.copyright.content = text
+
+## desc - specifies description
+TTAF.meta.desc =
+  element ttm:desc {
+    TTAF.meta.desc.attlist,
+    TTAF.meta.desc.content
+  }
+
+TTAF.meta.desc.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.meta.desc.content.extra = empty
+TTAF.meta.desc.content = text
+
+## name - specifies name
+TTAF.meta.name =
+  element ttm:name {
+    TTAF.meta.name.attlist,
+    TTAF.meta.name.content
+  }
+
+TTAF.meta.name.attlist &=
+  TTAF.Core.attrib.class,
+  attribute type { TTAF.MetadataNameType.datatype }
+
+TTAF.meta.name.content.extra = empty
+TTAF.meta.name.content = text
+
+## title - describes title
+TTAF.meta.title =
+  element ttm:title {
+    TTAF.meta.title.attlist,
+    TTAF.meta.title.content
+  }
+
+TTAF.meta.title.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.meta.title.content.extra = empty
+TTAF.meta.title.content = text
+
+## MetadataItems.class
+TTAF.MetadataItems.extra = empty
+TTAF.MetadataItems.class |=
+  TTAF.meta.agent |
+  TTAF.meta.copyright |
+  TTAF.meta.desc |
+  TTAF.meta.title |
+  TTAF.MetadataItems.extra
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-metadata.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,40 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Metadata Module ........................................
+# .......................................................................
+
+# namespace prefix bindings
+namespace tt = "http://www.w3.org/ns/ttml"
+namespace ttm = "http://www.w3.org/ns/ttml#metadata"
+namespace local = ""
+
+# meta - generic metadata
+TTAF.metadata =
+  element metadata {
+    TTAF.metadata.attlist,
+    TTAF.metadata.content
+  }
+
+TTAF.metadata.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.External.class =
+  element * - ( tt:* | ttm:* ) {
+    ( attribute * - ( xml:id ) { text }
+      | text
+      | TTAF.External.class
+    )*
+  }
+
+TTAF.metadata.content.extra = empty
+TTAF.metadata.content =
+  (TTAF.MetadataItems.class |
+   TTAF.External.class |
+   TTAF.metadata.content.extra)*
+
+TTAF.Metadata.class |=
+  TTAF.MetadataItems.class |
+  TTAF.metadata
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-parameter-attribs.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,49 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Parameter Attributes Module ............................
+# .......................................................................
+
+namespace ttp = "http://www.w3.org/ns/ttml#parameter"
+
+# Standard Metadata Attributes
+
+TTAF.cellResolution.attrib
+  = attribute ttp:cellResolution { TTAF.CellResolution.datatype }?
+TTAF.clockMode.attrib
+  = attribute ttp:clockMode { TTAF.ClockMode.datatype }?
+TTAF.dropMode.attrib
+  = attribute ttp:dropMode { TTAF.DropMode.datatype }?
+TTAF.frameRate.attrib
+  = attribute ttp:frameRate { TTAF.FrameRate.datatype }?
+TTAF.frameRateMultiplier.attrib
+  = attribute ttp:frameRateMultiplier { TTAF.FrameRateMultiplier.datatype }?
+TTAF.markerMode.attrib
+  = attribute ttp:markerMode { TTAF.MarkerMode.datatype }?
+TTAF.profile.attrib
+  = attribute ttp:profile { TTAF.Profile.datatype }?
+TTAF.pixelAspectRatio.attrib
+  = attribute ttp:pixelAspectRatio { TTAF.PixelAspectRatio.datatype }?
+TTAF.subFrameRate.attrib
+  = attribute ttp:subFrameRate { TTAF.SubFrameRate.datatype }?
+TTAF.tickRate.attrib
+  = attribute ttp:tickRate { TTAF.TickRate.datatype }?
+TTAF.timeBase.attrib
+  = attribute ttp:timeBase { TTAF.TimeBase.datatype }?
+
+# Parameter Attribute Class
+
+TTAF.Parameter.attrib.class &=
+  TTAF.cellResolution.attrib,
+  TTAF.clockMode.attrib,
+  TTAF.dropMode.attrib,
+  TTAF.frameRate.attrib,
+  TTAF.frameRateMultiplier.attrib,
+  TTAF.markerMode.attrib,
+  TTAF.pixelAspectRatio.attrib,
+  TTAF.profile.attrib,
+  TTAF.subFrameRate.attrib,
+  TTAF.tickRate.attrib,
+  TTAF.timeBase.attrib
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-parameter-items.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,95 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Parameter Items Module .................................
+# .......................................................................
+
+namespace ttp = "http://www.w3.org/ns/ttml#parameter"
+
+# profile - profile definition or use declaration
+TTAF.parameters.profile =
+  element ttp:profile {
+    TTAF.parameters.profile.attlist,
+    TTAF.parameters.profile.content
+  }
+
+TTAF.parameters.profile.attlist &=
+  TTAF.id.attrib,
+  attribute use { TTAF.Profile.datatype }?
+
+TTAF.parameters.profile.content.extra = empty
+TTAF.parameters.profile.content =
+  (TTAF.Metadata.class*,
+   TTAF.parameters.features*,
+   TTAF.parameters.extensions*,
+   TTAF.parameters.profile.content.extra*)
+
+# features - container for feature elements
+TTAF.parameters.features =
+  element ttp:features {
+    TTAF.parameters.features.attlist,
+    TTAF.parameters.features.content
+  }
+
+TTAF.parameters.features.attlist &=
+  TTAF.id.attrib,
+  attribute xml:base { TTAF.URI.datatype }?
+
+TTAF.parameters.features.content.extra = empty
+TTAF.parameters.features.content =
+  (TTAF.Metadata.class*,
+   TTAF.parameters.feature*,
+   TTAF.parameters.features.content.extra*)
+
+# feature - feature requirements declaration
+TTAF.parameters.feature =
+  element ttp:feature {
+    TTAF.parameters.feature.attlist,
+    TTAF.parameters.feature.content
+  }
+
+TTAF.parameters.feature.attlist =
+  TTAF.id.attrib,
+  attribute value { TTAF.FeatureValue.datatype }?
+
+TTAF.parameters.feature.content =
+  TTAF.FeatureDesignator.datatype
+
+# extensions - container for extension elements
+TTAF.parameters.extensions =
+  element ttp:extensions {
+    TTAF.parameters.extensions.attlist,
+    TTAF.parameters.extensions.content
+  }
+
+TTAF.parameters.extensions.attlist &=
+  TTAF.id.attrib,
+  attribute xml:base { TTAF.URI.datatype }?
+
+TTAF.parameters.extensions.content.extra = empty
+TTAF.parameters.extensions.content =
+  (TTAF.Metadata.class*,
+   TTAF.parameters.extension*,
+   TTAF.parameters.extensions.content.extra*)
+
+# extension - extension requirements declaration
+TTAF.parameters.extension =
+  element ttp:extension {
+    TTAF.parameters.extension.attlist,
+    TTAF.parameters.extension.content
+  }
+
+TTAF.parameters.extension.attlist =
+  TTAF.id.attrib,
+  attribute value { TTAF.ExtensionValue.datatype }?
+
+TTAF.parameters.extension.content =
+  TTAF.ExtensionDesignator.datatype
+
+## ParameterItems.class
+TTAF.ParameterItems.extra = empty
+TTAF.ParameterItems.class |=
+  TTAF.parameters.profile |
+  TTAF.ParameterItems.extra
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-parameters.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,10 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Parameters Module ......................................
+# .......................................................................
+
+TTAF.Parameters.class |=
+  TTAF.ParameterItems.class
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-styling-attribs.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,108 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Styling Attributes Module ..............................
+# .......................................................................
+
+namespace tt = "http://www.w3.org/ns/ttml"
+namespace tts = "http://www.w3.org/ns/ttml#styling"
+namespace local = ""
+
+# Standard Style Attributes
+
+TTAF.backgroundColor.attrib
+  = attribute tts:backgroundColor { TTAF.Color.datatype }?
+TTAF.color.attrib
+  = attribute tts:color { TTAF.Color.datatype }?
+TTAF.direction.attrib
+  = attribute tts:direction { TTAF.Direction.datatype }?
+TTAF.display.attrib
+  = attribute tts:display { TTAF.Display.datatype }?
+TTAF.displayAlign.attrib
+  = attribute tts:displayAlign { TTAF.DisplayAlign.datatype }?
+TTAF.extent.attrib
+  = attribute tts:extent { TTAF.Extent.datatype }?
+TTAF.fontFamily.attrib
+  = attribute tts:fontFamily { TTAF.FontFamily.datatype }?
+TTAF.fontSize.attrib
+  = attribute tts:fontSize { TTAF.FontSize.datatype }?
+TTAF.fontStyle.attrib
+  = attribute tts:fontStyle { TTAF.FontStyle.datatype }?
+TTAF.fontWeight.attrib
+  = attribute tts:fontWeight { TTAF.FontWeight.datatype }?
+TTAF.lineHeight.attrib
+  = attribute tts:lineHeight { TTAF.LineHeight.datatype }?
+TTAF.opacity.attrib
+  = attribute tts:opacity { TTAF.Opacity.datatype }?
+TTAF.origin.attrib
+  = attribute tts:origin { TTAF.Origin.datatype }?
+TTAF.overflow.attrib
+  = attribute tts:overflow { TTAF.Overflow.datatype }?
+TTAF.padding.attrib
+  = attribute tts:padding { TTAF.Padding.datatype }?
+TTAF.showBackground.attrib
+  = attribute tts:showBackground { TTAF.ShowBackground.datatype }?
+TTAF.textAlign.attrib
+  = attribute tts:textAlign { TTAF.TextAlign.datatype }?
+TTAF.textDecoration.attrib
+  = attribute tts:textDecoration { TTAF.TextDecoration.datatype }?
+TTAF.textOutline.attrib
+  = attribute tts:textOutline { TTAF.TextOutline.datatype }?
+TTAF.unicodeBidi.attrib
+  = attribute tts:unicodeBidi { TTAF.UnicodeBidi.datatype }?
+TTAF.visibility.attrib
+  = attribute tts:visibility { TTAF.Visibility.datatype }?
+TTAF.wrapOption.attrib
+  = attribute tts:wrapOption { TTAF.WrapOption.datatype }?
+TTAF.writingMode.attrib
+  = attribute tts:writingMode { TTAF.WritingMode.datatype }?
+TTAF.zIndex.attrib
+  = attribute tts:zIndex { TTAF.ZIndex.datatype }?
+
+# Extension Style Attributes
+
+TTAF.Styling.ForeignExtension.attrib =
+  attribute * - ( tt:* | tts:* | xml:* | local:* ) { text }
+
+# Styling Attribute Class
+
+TTAF.Styling.attrib.class &=
+  TTAF.backgroundColor.attrib,
+  TTAF.color.attrib,
+  TTAF.direction.attrib,
+  TTAF.display.attrib,
+  TTAF.displayAlign.attrib,
+  TTAF.extent.attrib,
+  TTAF.fontFamily.attrib,
+  TTAF.fontSize.attrib,
+  TTAF.fontStyle.attrib,
+  TTAF.fontWeight.attrib,
+  TTAF.lineHeight.attrib,
+  TTAF.opacity.attrib,
+  TTAF.origin.attrib,
+  TTAF.overflow.attrib,
+  TTAF.padding.attrib,
+  TTAF.showBackground.attrib,
+  TTAF.textAlign.attrib,
+  TTAF.textDecoration.attrib,
+  TTAF.textOutline.attrib,
+  TTAF.unicodeBidi.attrib,
+  TTAF.visibility.attrib,
+  TTAF.wrapOption.attrib,
+  TTAF.writingMode.attrib,
+  TTAF.zIndex.attrib
+
+# Style Binding Attribute Class
+
+TTAF.StyleBinding.attrib.class &=
+  TTAF.style.attrib
+
+# Styled Content Attribute Class
+
+TTAF.Styled.extra.attrib = empty
+TTAF.Styled.attrib.class &=
+  TTAF.Styling.attrib.class,
+  TTAF.StyleBinding.attrib.class,
+  TTAF.Styled.extra.attrib
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-styling.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,50 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Styling Module .........................................
+# .......................................................................
+
+# style reference attribute; must reference /tt/head/styling/style
+TTAF.style.attrib
+  = attribute style { xsd:IDREFS }?
+
+# styling - generic styling container
+TTAF.styling =
+  element styling {
+    TTAF.styling.attlist,
+    TTAF.styling.content
+  }
+
+TTAF.styling.attlist &=
+  TTAF.Core.attrib.class
+
+TTAF.styling.content.extra = empty
+TTAF.styling.content =
+  (TTAF.Metadata.class*,
+   TTAF.styling.defs.class*,
+   TTAF.styling.content.extra*)
+
+# style - style declaration
+TTAF.styling.style =
+  element style {
+    TTAF.styling.style.attlist,
+    TTAF.styling.style.content
+  }
+
+TTAF.styling.style.attlist =
+  TTAF.Core.attrib.class,
+  TTAF.style.attrib,
+  (TTAF.Styling.attrib.class |
+   TTAF.Styling.ForeignExtension.attrib+ )
+
+TTAF.styling.style.content.extra = empty
+TTAF.styling.style.content =
+  (TTAF.styling.style.content.extra)*
+
+# style definitions class
+TTAF.styling.defs.extra = empty
+TTAF.styling.defs.class = 
+  TTAF.styling.style
+  | TTAF.styling.defs.extra
+
+# .......................................................................
+# .......................................................................
+# .......................................................................
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11-timing-attribs.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,49 @@
+# .......................................................................
+# TT-AF 1.0 DFXP Timing Attributes Module ...............................
+# .......................................................................
+
+# Timing Attributes
+
+TTAF.timing.begin.attrib
+  = attribute begin { TTAF.TimeCoordinate.datatype }?
+TTAF.timing.dur.attrib
+  = attribute dur { TTAF.TimeDuration.datatype }?
+TTAF.timing.end.attrib
+  = attribute end { TTAF.TimeCoordinate.datatype }?
+TTAF.timing.timeContainer.attrib
+  = attribute timeContainer { TTAF.TimeContainer.datatype }?
+
+# Timing Interval Attribute class
+
+TTAF.TimingInterval.extra.attrib = empty
+TTAF.TimingInterval.attrib.class &=
+  TTAF.timing.begin.attrib,
+  TTAF.timing.dur.attrib,
+  TTAF.timing.end.attrib,
+  TTAF.TimingInterval.extra.attrib
+
+# Timing Container Attribute class
+
+TTAF.TimingContainer.extra.attrib = empty
+TTAF.TimingContainer.attrib.class &=
+  TTAF.timing.timeContainer.attrib,
+  TTAF.TimingContainer.extra.attrib
+
+# Timed Content Attribute Class
+
+TTAF.Timed.extra.attrib = empty
+TTAF.Timed.attrib.class &=
+  TTAF.TimingInterval.attrib.class,
+  TTAF.Timed.extra.attrib
+
+# Timed Content Container Attribute Class
+
+TTAF.TimedContainer.extra.attrib = empty
+TTAF.TimedContainer.attrib.class &=
+  TTAF.Timed.attrib.class,
+  TTAF.TimingContainer.attrib.class,
+  TTAF.TimedContainer.extra.attrib
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ttml11/spec/rnc/ttml11.rnc	Wed Apr 11 23:50:28 2012 -0600
@@ -0,0 +1,31 @@
+# .......................................................................
+# TT-AF 1.0 Distribution Format Exchange Profile (DFXP) Schema ..........
+# .......................................................................
+
+# default namespace
+default namespace tt = "http://www.w3.org/ns/ttml"
+
+# generic tt modules
+include "ttaf1-dfxp-datatypes.rnc"
+include "ttaf1-dfxp-classes.rnc"
+include "ttaf1-dfxp-core-attribs.rnc"
+include "ttaf1-dfxp-parameter-attribs.rnc"
+include "ttaf1-dfxp-metadata-attribs.rnc"
+include "ttaf1-dfxp-styling-attribs.rnc"
+include "ttaf1-dfxp-timing-attribs.rnc"
+include "ttaf1-dfxp-parameter-items.rnc"
+include "ttaf1-dfxp-parameters.rnc"
+include "ttaf1-dfxp-metadata-items.rnc"
+include "ttaf1-dfxp-metadata.rnc"
+include "ttaf1-dfxp-styling.rnc"
+include "ttaf1-dfxp-animation.rnc"
+include "ttaf1-dfxp-layout.rnc"
+include "ttaf1-dfxp-content.rnc"
+include "ttaf1-dfxp-head.rnc"
+include "ttaf1-dfxp-document.rnc"
+
+start = TTAF.tt | TTAF.parameters.profile
+
+# .......................................................................
+# .......................................................................
+# .......................................................................

--- a/ttml11/spec/ttaf1-dfxp.html	Wed Apr 11 23:21:22 2012 -0600
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,8492 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!DOCTYPE html
-  PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-us" lang="en-us"><head><meta http-equiv="Content-Type" content="application/xhtml+xml; charset=utf-8"/><title>Timed Text Markup Language (TTML) 1.0 (Second Edition) -- (Editors' copy)</title><style type="text/css">
-code           { font-family: monospace; }
-
-div.constraint,
-div.issue,
-div.note,
-div.notice     { margin-left: 2em; }
-
-ol.enumar      { list-style-type: decimal; }
-ol.enumla      { list-style-type: lower-alpha; }
-ol.enumlr      { list-style-type: lower-roman; }
-ol.enumua      { list-style-type: upper-alpha; }
-ol.enumur      { list-style-type: upper-roman; }
-
-
-div.exampleInner pre { margin-left: 1em;
-                       margin-top: 0em; margin-bottom: 0em}
-div.exampleOuter {border: 4px double gray;
-                  margin: 0em; padding: 0em}
-div.exampleInner { background-color: #d5dee3;
-                   border-top-width: 4px;
-                   border-top-style: double;
-                   border-top-color: #d3d3d3;
-                   border-bottom-width: 4px;
-                   border-bottom-style: double;
-                   border-bottom-color: #d3d3d3;
-                   padding: 4px; margin: 0em }
-div.exampleWrapper { margin: 4px }
-div.exampleHeader { font-weight: bold;
-                    margin: 4px}
-
-li p { margin-top: 0.3em; margin-bottom: 0.3em; }
-div.issue { border: 2px solid black; background-color: #ffff66; padding: 0em 1em; margin: 0em 0em }
-table.ednote { border-collapse: collapse; border: 2px solid black; width: 85% }
-table.ednote td { background-color: #ddaa66; border: 2px solid black }
-table.acronyms td.label { width: 15% }
-table.acronyms td.def { width: 65% }
-table.graphic { border: 0px none black; width: 100%; border-collapse: collapse }
-table.graphic caption { font-weight: bold; text-align: center; padding-bottom: 0.5em }
-table.graphic td { border: 0px none black; text-align: center }
-table.common { border: 2px solid black; width: 85%; border-collapse: collapse }
-table.common caption { font-weight: bold; text-align: left; padding-bottom: 0.5em }
-table.common th { padding: 0em 0.5em; border: 2px solid black; text-align: left }
-table.common td { padding: 0em 0.5em; border: 2px solid black }
-table.syntax { border: 0px solid black; width: 85%; border-collapse: collapse }
-table.syntax caption { font-weight: bold; text-align: left; padding-bottom: 0.5em }
-table.syntax th { border: 0px solid black; text-align: left }
-table.syntax td { border: 0px solid black }
-table.syntax div { background-color: #ffffc8 }
-table.example { border: 0px solid black; width: 85%; border-collapse: collapse }
-table.example caption { font-weight: bold; text-align: left; padding-bottom: 0.5em }
-table.example th { border: 0px solid black; text-align: left }
-table.example td { border: 0px solid black }
-table.example div { background-color: #c8ffff }
-table.example-images { text-align: center; border: 0px solid black; width: 85%; border-collapse: collapse }
-table.example-images caption { font-weight: bold; text-align: center; padding-bottom: 0.5em }
-table.example-images td { border: 0px solid black; text-align: center }
-table.example-images-bordered { text-align: center; border: 0px solid black; width: 85%; border-collapse: collapse }
-table.example-images-bordered caption { font-weight: bold; text-align: center; padding-bottom: 0.5em }
-table.example-images-bordered td { border: 1px solid red; text-align: left }
-.tbd { background-color: #ffff33; border: 2px solid black; width: 85% }
-.strong { font-weight: bold }
-.reqattr { font-weight: bold }
-.optattr { font-style: italic }
-
-.diff-add  { color: red; background-color: #99FF99; }
-.diff-del  { color: red; text-decoration: line-through; background-color: #99FF99; }
-.diff-chg  { background-color: #99FF99; }
-q.diff-off  {}
-</style><link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-ED.css"/></head><body>Last Modified: $Date: 2012/03/15 06:53:57 $<div id="revisions"/><div class="head">
-<h1><a name="title" id="title"/>Timed Text Markup Language (TTML) 1.0 (Second Edition)</h1>
-<h2><a name="w3c-doctype" id="w3c-doctype"/>Editors' copy $Date: 2012/03/15 06:53:57 $ @@ @@@@ @@@@</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>
-</dd><dt>Editor:</dt><dd>Glenn Adams, Cox Communications, Inc.</dd><dt>Contributing Authors:</dt><dd>Mike Dolan, Invited Expert</dd><dd>Geoff Freed, WGBH National Center for Accessible Media</dd><dd>Sean Hayes, Microsoft</dd><dd>Erik Hodge, RealNetworks</dd><dd>David Kirby, British Broadcasting Corporation (BBC)</dd><dd>Thierry Michel, W3C</dd><dd>Dave Singer, Apple Computer</dd></dl><p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © @@@@ <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>), 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 name="abstract" id="abstract"/>Abstract</h2><p>This document specifies the Timed Text Markup Language (TTML) 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;text&gt;</code> or 
-<code>&lt;textstream&gt;</code> media object element in a <a href="#smil21">[SMIL 2.1]</a> document.</p></div><div><h2><a name="status" id="status"/>Status of this Document</h2><p><strong>This document is an editor's copy that has no official standing.</strong></p><p/></div><div class="toc">
-<h2><a name="contents" id="contents"/>Table of Contents</h2><p class="toc">1 <a href="#intro">Introduction</a><br/>
-    1.1 <a href="#model">System Model</a><br/>
-    1.2 <a href="#example">Document Example</a><br/>
-2 <a href="#definitions">Definitions</a><br/>
-    2.1 <a href="#acronyms">Acronyms</a><br/>
-    2.2 <a href="#terms">Terminology</a><br/>
-    2.3 <a href="#conventions">Documentation Conventions</a><br/>
-3 <a href="#conformance">Conformance</a><br/>
-    3.1 <a href="#conformance-content">Content Conformance</a><br/>
-    3.2 <a href="#conformance-processor">Processor Conformance</a><br/>
-        3.2.1 <a href="#conformance-generic-processor">Generic Processor Conformance</a><br/>
-        3.2.2 <a href="#conformance-transformation-processor">Transformation Processor Conformance</a><br/>
-        3.2.3 <a href="#conformance-presentation-processor">Presentation Processor Conformance</a><br/>
-    3.3 <a href="#claims">Claims</a><br/>
-4 <a href="#doctypes">Document Types</a><br/>
-    4.1 <a href="#dfxp-content-doctype">DFXP Content</a><br/>
-5 <a href="#vocabulary">Vocabulary</a><br/>
-    5.1 <a href="#vocabulary-namespaces">Namespaces</a><br/>
-    5.2 <a href="#vocabulary-profiles">Profiles</a><br/>
-    5.3 <a href="#vocabulary-overview">Catalog</a><br/>
-        5.3.1 <a href="#core-vocabulary-overview">Core Catalog</a><br/>
-        5.3.2 <a href="#extension-vocabulary-overview">Extension Catalog</a><br/>
-6 <a href="#parameters">Parameters</a><br/>
-    6.1 <a href="#parameter-element-vocabulary">Parameter Element Vocabulary</a><br/>
-        6.1.1 <a href="#parameter-vocabulary-profile">ttp:profile</a><br/>
-        6.1.2 <a href="#parameter-vocabulary-features">ttp:features</a><br/>
-        6.1.3 <a href="#parameter-vocabulary-feature">ttp:feature</a><br/>
-        6.1.4 <a href="#parameter-vocabulary-extensions">ttp:extensions</a><br/>
-        6.1.5 <a href="#parameter-vocabulary-extension">ttp:extension</a><br/>
-    6.2 <a href="#parameter-attribute-vocabulary">Parameter Attribute Vocabulary</a><br/>
-        6.2.1 <a href="#parameter-attribute-cellResolution">ttp:cellResolution</a><br/>
-        6.2.2 <a href="#parameter-attribute-clockMode">ttp:clockMode</a><br/>
-        6.2.3 <a href="#parameter-attribute-dropMode">ttp:dropMode</a><br/>
-        6.2.4 <a href="#parameter-attribute-frameRate">ttp:frameRate</a><br/>
-        6.2.5 <a href="#parameter-attribute-frameRateMultiplier">ttp:frameRateMultiplier</a><br/>
-        6.2.6 <a href="#parameter-attribute-markerMode">ttp:markerMode</a><br/>
-        6.2.7 <a href="#parameter-attribute-pixelAspectRatio">ttp:pixelAspectRatio</a><br/>
-        6.2.8 <a href="#parameter-attribute-profile">ttp:profile</a><br/>
-        6.2.9 <a href="#parameter-attribute-subFrameRate">ttp:subFrameRate</a><br/>
-        6.2.10 <a href="#parameter-attribute-tickRate">ttp:tickRate</a><br/>
-        6.2.11 <a href="#parameter-attribute-timeBase">ttp:timeBase</a><br/>
-7 <a href="#content">Content</a><br/>
-    7.1 <a href="#content-element-vocabulary">Content Element Vocabulary</a><br/>
-        7.1.1 <a href="#document-structure-vocabulary-tt">tt</a><br/>
-        7.1.2 <a href="#document-structure-vocabulary-head">head</a><br/>
-        7.1.3 <a href="#document-structure-vocabulary-body">body</a><br/>
-        7.1.4 <a href="#content-vocabulary-div">div</a><br/>
-        7.1.5 <a href="#content-vocabulary-p">p</a><br/>
-        7.1.6 <a href="#content-vocabulary-span">span</a><br/>
-        7.1.7 <a href="#content-vocabulary-br">br</a><br/>
-    7.2 <a href="#content-attribute-vocabulary">Content Attribute Vocabulary</a><br/>
-        7.2.1 <a href="#content-attribute-id">xml:id</a><br/>
-        7.2.2 <a href="#content-attribute-lang">xml:lang</a><br/>
-        7.2.3 <a href="#content-attribute-space">xml:space</a><br/>
-8 <a href="#styling">Styling</a><br/>
-    8.1 <a href="#styling-element-vocabulary">Styling Element Vocabulary</a><br/>
-        8.1.1 <a href="#styling-vocabulary-styling">styling</a><br/>
-        8.1.2 <a href="#styling-vocabulary-style">style</a><br/>
-    8.2 <a href="#styling-attribute-vocabulary">Styling Attribute Vocabulary</a><br/>
-        8.2.1 <a href="#style-attribute-style">style</a><br/>
-        8.2.2 <a href="#style-attribute-backgroundColor">tts:backgroundColor</a><br/>
-        8.2.3 <a href="#style-attribute-color">tts:color</a><br/>
-        8.2.4 <a href="#style-attribute-direction">tts:direction</a><br/>
-        8.2.5 <a href="#style-attribute-display">tts:display</a><br/>
-        8.2.6 <a href="#style-attribute-displayAlign">tts:displayAlign</a><br/>
-        8.2.7 <a href="#style-attribute-extent">tts:extent</a><br/>
-        8.2.8 <a href="#style-attribute-fontFamily">tts:fontFamily</a><br/>
-        8.2.9 <a href="#style-attribute-fontSize">tts:fontSize</a><br/>
-        8.2.10 <a href="#style-attribute-fontStyle">tts:fontStyle</a><br/>
-        8.2.11 <a href="#style-attribute-fontWeight">tts:fontWeight</a><br/>
-        8.2.12 <a href="#style-attribute-lineHeight">tts:lineHeight</a><br/>
-        8.2.13 <a href="#style-attribute-opacity">tts:opacity</a><br/>
-        8.2.14 <a href="#style-attribute-origin">tts:origin</a><br/>
-        8.2.15 <a href="#style-attribute-overflow">tts:overflow</a><br/>
-        8.2.16 <a href="#style-attribute-padding">tts:padding</a><br/>
-        8.2.17 <a href="#style-attribute-showBackground">tts:showBackground</a><br/>
-        8.2.18 <a href="#style-attribute-textAlign">tts:textAlign</a><br/>
-        8.2.19 <a href="#style-attribute-textDecoration">tts:textDecoration</a><br/>
-        8.2.20 <a href="#style-attribute-textOutline">tts:textOutline</a><br/>
-        8.2.21 <a href="#style-attribute-unicodeBidi">tts:unicodeBidi</a><br/>
-        8.2.22 <a href="#style-attribute-visibility">tts:visibility</a><br/>
-        8.2.23 <a href="#style-attribute-wrapOption">tts:wrapOption</a><br/>
-        8.2.24 <a href="#style-attribute-writingMode">tts:writingMode</a><br/>
-        8.2.25 <a href="#style-attribute-zIndex">tts:zIndex</a><br/>
-    8.3 <a href="#styling-style-value-expressions">Style Value Expressions</a><br/>
-        8.3.1 <a href="#style-value-alpha">&lt;alpha&gt;</a><br/>
-        8.3.2 <a href="#style-value-color">&lt;color&gt;</a><br/>
-        8.3.3 <a href="#style-value-digit">&lt;digit&gt;</a><br/>
-        8.3.4 <a href="#style-value-duration">&lt;duration&gt;</a><br/>
-        8.3.5 <a href="#style-value-familyName">&lt;familyName&gt;</a><br/>
-        8.3.6 <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a><br/>
-        8.3.7 <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a><br/>
-        8.3.8 <a href="#style-value-integer">&lt;integer&gt;</a><br/>
-        8.3.9 <a href="#style-value-length">&lt;length&gt;</a><br/>
-        8.3.10 <a href="#style-value-namedColor">&lt;namedColor&gt;</a><br/>
-        8.3.11 <a href="#style-value-quotedString">&lt;quotedString&gt;</a><br/>
-        8.3.12 <a href="#style-value-string">&lt;string&gt;</a><br/>
-    8.4 <a href="#semantics-style-resolution">Style Resolution</a><br/>
-        8.4.1 <a href="#semantics-style-association">Style Association</a><br/>
-            8.4.1.1 <a href="#semantics-style-association-inline">Inline Styling</a><br/>
-            8.4.1.2 <a href="#semantics-style-association-referential">Referential Styling</a><br/>
-            8.4.1.3 <a href="#semantics-style-association-chained-referential">Chained Referential Styling</a><br/>
-            8.4.1.4 <a href="#semantics-style-association-nested">Nested Styling</a><br/>
-        8.4.2 <a href="#semantics-style-inheritance">Style Inheritance</a><br/>
-            8.4.2.1 <a href="#semantics-style-inheritance-content">Content Style Inheritance</a><br/>
-            8.4.2.2 <a href="#semantics-style-inheritance-region">Region Style Inheritance</a><br/>
-        8.4.3 <a href="#semantics-style-resolution-value-categories">Style Resolution Value Categories</a><br/>
-            8.4.3.1 <a href="#semantics-style-resolved-value-category-specified">Specified Values</a><br/>
-            8.4.3.2 <a href="#semantics-style-resolved-value-category-computed">Computed Values</a><br/>
-            8.4.3.3 <a href="#semantics-style-resolved-value-category-actual">Actual Values</a><br/>
-        8.4.4 <a href="#semantics-style-resolution-processing">Style Resolution Processing</a><br/>
-            8.4.4.1 <a href="#semantics-style-resolution-processing-definitions">Conceptual Definitions</a><br/>
-            8.4.4.2 <a href="#semantics-style-resolution-processing-sss">Specified Style Set Processing</a><br/>
-            8.4.4.3 <a href="#semantics-style-resolution-processing-css">Computed Style Set Processing</a><br/>
-            8.4.4.4 <a href="#semantics-style-resolution-process-overall">Style Resolution Process</a><br/>
-9 <a href="#layout">Layout</a><br/>
-    9.1 <a href="#layout-element-vocabulary">Layout Element Vocabulary</a><br/>
-        9.1.1 <a href="#layout-vocabulary-layout">layout</a><br/>
-        9.1.2 <a href="#layout-vocabulary-region">region</a><br/>
-    9.2 <a href="#layout-attribute-vocabulary">Layout Attribute Vocabulary</a><br/>
-        9.2.1 <a href="#layout-attribute-region">region</a><br/>
-    9.3 <a href="#semantics-region-layout">Region Layout and Presentation</a><br/>
-        9.3.1 <a href="#semantics-default-region">Default Region</a><br/>
-        9.3.2 <a href="#semantics-region-layout-step-1">Intermediate Synchronic Document Construction</a><br/>
-        9.3.3 <a href="#semantics-region-layout-step-2">Synchronic Flow Processing</a><br/>
-        9.3.4 <a href="#semantics-region-layout-example">Elaborated Example (Informative)</a><br/>
-    9.4 <a href="#semantics-line-layout">Line Layout</a><br/>
-10 <a href="#timing">Timing</a><br/>
-    10.1 <a href="#timing-element-vocabulary">Timing Element Vocabulary</a><br/>
-    10.2 <a href="#timing-attribute-vocabulary">Timing Attribute Vocabulary</a><br/>
-        10.2.1 <a href="#timing-attribute-begin">begin</a><br/>
-        10.2.2 <a href="#timing-attribute-end">end</a><br/>
-        10.2.3 <a href="#timing-attribute-dur">dur</a><br/>
-        10.2.4 <a href="#timing-attribute-timeContainer">timeContainer</a><br/>
-    10.3 <a href="#timing-time-value-expressions">Time Value Expressions</a><br/>
-        10.3.1 <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a><br/>
-    10.4 <a href="#timing-time-intervals">Time Intervals</a><br/>
-11 <a href="#animation">Animation</a><br/>
-    11.1 <a href="#animation-element-vocabulary">Animation Element Vocabulary</a><br/>
-        11.1.1 <a href="#animation-vocabulary-set">set</a><br/>
-    11.2 <a href="#animation-attribute-vocabulary">Animation Attribute Vocabulary</a><br/>
-12 <a href="#metadata">Metadata</a><br/>
-    12.1 <a href="#metadata-element-vocabulary">Metadata Element Vocabulary</a><br/>
-        12.1.1 <a href="#metadata-vocabulary-metadata">metadata</a><br/>
-        12.1.2 <a href="#metadata-vocabulary-title">ttm:title</a><br/>
-        12.1.3 <a href="#metadata-vocabulary-desc">ttm:desc</a><br/>
-        12.1.4 <a href="#metadata-vocabulary-copyright">ttm:copyright</a><br/>
-        12.1.5 <a href="#metadata-vocabulary-agent">ttm:agent</a><br/>
-        12.1.6 <a href="#metadata-vocabulary-name">ttm:name</a><br/>
-        12.1.7 <a href="#metadata-vocabulary-actor">ttm:actor</a><br/>
-    12.2 <a href="#metadata-attribute-vocabulary">Metadata Attribute Vocabulary</a><br/>
-        12.2.1 <a href="#metadata-attribute-agent">ttm:agent</a><br/>
-        12.2.2 <a href="#metadata-attribute-role">ttm:role</a><br/>
-</p>
-<h3><a name="appendices" id="appendices"/>Appendices</h3><p class="toc">A <a href="#reduced-infoset">Reduced XML Infoset</a><br/>
-    A.1 <a href="#reduced-infoset-document">Document Information Item</a><br/>
-    A.2 <a href="#reduced-infoset-element">Element Information Item</a><br/>
-    A.3 <a href="#reduced-infoset-attribute">Attribute Information Item</a><br/>
-    A.4 <a href="#reduced-infoset-character">Character Information Item</a><br/>
-B <a href="#schemas">Schemas</a><br/>
-    B.1 <a href="#dfxp-schema-rnc">Relax NG Schema</a><br/>
-        B.1.1 <a href="#rnc-dfxp-driver-schema">Driver</a><br/>
-        B.1.2 <a href="#rnc-dfxp-modules">Modules</a><br/>
-            B.1.2.1 <a href="#rnc-dfxp-animation-module">Animation Module</a><br/>
-            B.1.2.2 <a href="#rnc-dfxp-classes-module">Classes Module</a><br/>
-            B.1.2.3 <a href="#rnc-dfxp-content-module">Content Module</a><br/>
-            B.1.2.4 <a href="#rnc-dfxp-core-attribs-module">Core Attributes Module</a><br/>
-            B.1.2.5 <a href="#rnc-dfxp-datatypes-module">Data Types Module</a><br/>
-            B.1.2.6 <a href="#rnc-dfxp-document-module">Document Module</a><br/>
-            B.1.2.7 <a href="#rnc-dfxp-head-module">Header Module</a><br/>
-            B.1.2.8 <a href="#rnc-dfxp-layout-module">Layout Module</a><br/>
-            B.1.2.9 <a href="#rnc-dfxp-metadata-module">Metadata Module</a><br/>
-            B.1.2.10 <a href="#rnc-dfxp-metadata-items-module">Metadata Items Module</a><br/>
-            B.1.2.11 <a href="#rnc-dfxp-metadata-attribs-module">Metadata Attributes Module</a><br/>
-            B.1.2.12 <a href="#rnc-dfxp-parameters-module">Parameters Module</a><br/>
-            B.1.2.13 <a href="#rnc-dfxp-parameter-items-module">Parameter Items Module</a><br/>
-            B.1.2.14 <a href="#rnc-dfxp-parameter-attribs-module">Parameter Attributes Module</a><br/>
-            B.1.2.15 <a href="#rnc-dfxp-styling-attribs-module">Styling Attributes Module</a><br/>
-            B.1.2.16 <a href="#rnc-dfxp-styling-module">Styling Module</a><br/>
-            B.1.2.17 <a href="#rnc-dfxp-timing-attribs-module">Timing Attributes Module</a><br/>
-    B.2 <a href="#dfxp-schema-xsd">XML Schema Definition (XSD) Schema</a><br/>
-        B.2.1 <a href="#xsd-dfxp-driver-schema">Driver</a><br/>
-        B.2.2 <a href="#xsd-dfxp-modules">Modules</a><br/>
-            B.2.2.1 <a href="#xsd-dfxp-animation-module">Animation Module</a><br/>
-            B.2.2.2 <a href="#xsd-dfxp-content-module">Content Module</a><br/>
-            B.2.2.3 <a href="#xsd-dfxp-core-attribs-module">Core Attributes Module</a><br/>
-            B.2.2.4 <a href="#xsd-dfxp-datatypes-module">Data Types Module</a><br/>
-            B.2.2.5 <a href="#xsd-dfxp-document-module">Document Module</a><br/>
-            B.2.2.6 <a href="#xsd-dfxp-head-module">Header Module</a><br/>
-            B.2.2.7 <a href="#xsd-dfxp-layout-module">Layout Module</a><br/>
-            B.2.2.8 <a href="#xsd-dfxp-metadata-module">Metadata Module</a><br/>
-            B.2.2.9 <a href="#xsd-dfxp-metadata-items-module">Metadata Items Module</a><br/>
-            B.2.2.10 <a href="#xsd-dfxp-metadata-attribs-module">Metadata Attributes Module</a><br/>
-            B.2.2.11 <a href="#xsd-dfxp-parameters-module">Parameters Module</a><br/>
-            B.2.2.12 <a href="#xsd-dfxp-parameter-items-module">Parameter Items Module</a><br/>
-            B.2.2.13 <a href="#xsd-dfxp-parameter-attribs-module">Parameter Attributes Module</a><br/>
-            B.2.2.14 <a href="#xsd-dfxp-styling-attribs-module">Styling Attributes Module</a><br/>
-            B.2.2.15 <a href="#xsd-dfxp-styling-module">Styling Module</a><br/>
-            B.2.2.16 <a href="#xsd-dfxp-timing-attribs-module">Timing Attributes Module</a><br/>
-            B.2.2.17 <a href="#xsd-dfxp-xml-attrs-module">XML Attributes Module</a><br/>
-C <a href="#media-type-registration">Media Type Registration</a><br/>
-D <a href="#features">Features</a><br/>
-    D.1 <a href="#feature-designations">Feature Designations</a><br/>
-        D.1.1 <a href="#feature-animation">#animation</a><br/>
-        D.1.2 <a href="#feature-backgroundColor">#backgroundColor</a><br/>
-        D.1.3 <a href="#feature-backgroundColor-block">#backgroundColor-block</a><br/>
-        D.1.4 <a href="#feature-backgroundColor-inline">#backgroundColor-inline</a><br/>
-        D.1.5 <a href="#feature-backgroundColor-region">#backgroundColor-region</a><br/>
-        D.1.6 <a href="#feature-bidi">#bidi</a><br/>
-        D.1.7 <a href="#feature-cellResolution">#cellResolution</a><br/>
-        D.1.8 <a href="#feature-clockMode">#clockMode</a><br/>
-        D.1.9 <a href="#feature-clockMode-gps">#clockMode-gps</a><br/>
-        D.1.10 <a href="#feature-clockMode-local">#clockMode-local</a><br/>
-        D.1.11 <a href="#feature-clockMode-utc">#clockMode-utc</a><br/>
-        D.1.12 <a href="#feature-color">#color</a><br/>
-        D.1.13 <a href="#feature-content">#content</a><br/>
-        D.1.14 <a href="#feature-core">#core</a><br/>
-        D.1.15 <a href="#feature-direction">#direction</a><br/>
-        D.1.16 <a href="#feature-display">#display</a><br/>
-        D.1.17 <a href="#feature-display-block">#display-block</a><br/>
-        D.1.18 <a href="#feature-display-inline">#display-inline</a><br/>
-        D.1.19 <a href="#feature-display-region">#display-region</a><br/>
-        D.1.20 <a href="#feature-displayAlign">#displayAlign</a><br/>
-        D.1.21 <a href="#feature-dropMode">#dropMode</a><br/>
-        D.1.22 <a href="#feature-dropMode-dropNTSC">#dropMode-dropNTSC</a><br/>
-        D.1.23 <a href="#feature-dropMode-dropPAL">#dropMode-dropPAL</a><br/>
-        D.1.24 <a href="#feature-dropMode-nonDrop">#dropMode-nonDrop</a><br/>
-        D.1.25 <a href="#feature-extent">#extent</a><br/>
-        D.1.26 <a href="#feature-extent-region">#extent-region</a><br/>
-        D.1.27 <a href="#feature-extent-root">#extent-root</a><br/>
-        D.1.28 <a href="#feature-fontFamily">#fontFamily</a><br/>
-        D.1.29 <a href="#feature-fontFamily-generic">#fontFamily-generic</a><br/>
-        D.1.30 <a href="#feature-fontFamily-non-generic">#fontFamily-non-generic</a><br/>
-        D.1.31 <a href="#feature-fontSize">#fontSize</a><br/>
-        D.1.32 <a href="#feature-fontSize-anamorphic">#fontSize-anamorphic</a><br/>
-        D.1.33 <a href="#feature-fontSize-isomorphic">#fontSize-isomorphic</a><br/>
-        D.1.34 <a href="#feature-fontStyle">#fontStyle</a><br/>
-        D.1.35 <a href="#feature-fontStyle-italic">#fontStyle-italic</a><br/>
-        D.1.36 <a href="#feature-fontStyle-oblique">#fontStyle-oblique</a><br/>
-        D.1.37 <a href="#feature-fontWeight">#fontWeight</a><br/>
-        D.1.38 <a href="#feature-fontWeight-bold">#fontWeight-bold</a><br/>
-        D.1.39 <a href="#feature-frameRate">#frameRate</a><br/>
-        D.1.40 <a href="#feature-frameRateMultiplier">#frameRateMultiplier</a><br/>
-        D.1.41 <a href="#feature-layout">#layout</a><br/>
-        D.1.42 <a href="#feature-length">#length</a><br/>
-        D.1.43 <a href="#feature-length-cell">#length-cell</a><br/>
-        D.1.44 <a href="#feature-length-em">#length-em</a><br/>
-        D.1.45 <a href="#feature-length-integer">#length-integer</a><br/>
-        D.1.46 <a href="#feature-length-negative">#length-negative</a><br/>
-        D.1.47 <a href="#feature-length-percentage">#length-percentage</a><br/>
-        D.1.48 <a href="#feature-length-pixel">#length-pixel</a><br/>
-        D.1.49 <a href="#feature-length-positive">#length-positive</a><br/>
-        D.1.50 <a href="#feature-length-real">#length-real</a><br/>
-        D.1.51 <a href="#feature-lineBreak-uax14">#lineBreak-uax14</a><br/>
-        D.1.52 <a href="#feature-lineHeight">#lineHeight</a><br/>
-        D.1.53 <a href="#feature-markerMode">#markerMode</a><br/>
-        D.1.54 <a href="#feature-markerMode-continuous">#markerMode-continuous</a><br/>
-        D.1.55 <a href="#feature-markerMode-discontinuous">#markerMode-discontinuous</a><br/>
-        D.1.56 <a href="#feature-metadata">#metadata</a><br/>
-        D.1.57 <a href="#feature-nested-div">#nested-div</a><br/>
-        D.1.58 <a href="#feature-nested-span">#nested-span</a><br/>
-        D.1.59 <a href="#feature-opacity">#opacity</a><br/>
-        D.1.60 <a href="#feature-origin">#origin</a><br/>
-        D.1.61 <a href="#feature-overflow">#overflow</a><br/>
-        D.1.62 <a href="#feature-overflow-visible">#overflow-visible</a><br/>
-        D.1.63 <a href="#feature-padding">#padding</a><br/>
-        D.1.64 <a href="#feature-padding-1">#padding-1</a><br/>
-        D.1.65 <a href="#feature-padding-2">#padding-2</a><br/>
-        D.1.66 <a href="#feature-padding-3">#padding-3</a><br/>
-        D.1.67 <a href="#feature-padding-4">#padding-4</a><br/>
-        D.1.68 <a href="#feature-pixelAspectRatio">#pixelAspectRatio</a><br/>
-        D.1.69 <a href="#feature-presentation">#presentation</a><br/>
-        D.1.70 <a href="#feature-profile">#profile</a><br/>
-        D.1.71 <a href="#feature-showBackground">#showBackground</a><br/>
-        D.1.72 <a href="#feature-structure">#structure</a><br/>
-        D.1.73 <a href="#feature-styling">#styling</a><br/>
-        D.1.74 <a href="#feature-styling-chained">#styling-chained</a><br/>
-        D.1.75 <a href="#feature-styling-inheritance-content">#styling-inheritance-content</a><br/>
-        D.1.76 <a href="#feature-styling-inheritance-region">#styling-inheritance-region</a><br/>
-        D.1.77 <a href="#feature-styling-inline">#styling-inline</a><br/>
-        D.1.78 <a href="#feature-styling-nested">#styling-nested</a><br/>
-        D.1.79 <a href="#feature-styling-referential">#styling-referential</a><br/>
-        D.1.80 <a href="#feature-subFrameRate">#subFrameRate</a><br/>
-        D.1.81 <a href="#feature-textAlign">#textAlign</a><br/>
-        D.1.82 <a href="#feature-textAlign-absolute">#textAlign-absolute</a><br/>
-        D.1.83 <a href="#feature-textAlign-relative">#textAlign-relative</a><br/>
-        D.1.84 <a href="#feature-textDecoration">#textDecoration</a><br/>
-        D.1.85 <a href="#feature-textDecoration-over">#textDecoration-over</a><br/>
-        D.1.86 <a href="#feature-textDecoration-through">#textDecoration-through</a><br/>
-        D.1.87 <a href="#feature-textDecoration-under">#textDecoration-under</a><br/>
-        D.1.88 <a href="#feature-textOutline">#textOutline</a><br/>
-        D.1.89 <a href="#feature-textOutline-blurred">#textOutline-blurred</a><br/>
-        D.1.90 <a href="#feature-textOutline-unblurred">#textOutline-unblurred</a><br/>
-        D.1.91 <a href="#feature-tickRate">#tickRate</a><br/>
-        D.1.92 <a href="#feature-timeBase-clock">#timeBase-clock</a><br/>
-        D.1.93 <a href="#feature-timeBase-media">#timeBase-media</a><br/>
-        D.1.94 <a href="#feature-timeBase-smpte">#timeBase-smpte</a><br/>
-        D.1.95 <a href="#feature-timeContainer">#timeContainer</a><br/>
-        D.1.96 <a href="#feature-time-clock">#time-clock</a><br/>
-        D.1.97 <a href="#feature-time-clock-with-frames">#time-clock-with-frames</a><br/>
-        D.1.98 <a href="#feature-time-offset">#time-offset</a><br/>
-        D.1.99 <a href="#feature-time-offset-with-frames">#time-offset-with-frames</a><br/>
-        D.1.100 <a href="#feature-time-offset-with-ticks">#time-offset-with-ticks</a><br/>
-        D.1.101 <a href="#feature-timing">#timing</a><br/>
-        D.1.102 <a href="#feature-transformation">#transformation</a><br/>
-        D.1.103 <a href="#feature-unicodeBidi">#unicodeBidi</a><br/>
-        D.1.104 <a href="#feature-visibility">#visibility</a><br/>
-        D.1.105 <a href="#feature-visibility-block">#visibility-block</a><br/>
-        D.1.106 <a href="#feature-visibility-inline">#visibility-inline</a><br/>
-        D.1.107 <a href="#feature-visibility-region">#visibility-region</a><br/>
-        D.1.108 <a href="#feature-wrapOption">#wrapOption</a><br/>
-        D.1.109 <a href="#feature-writingMode">#writingMode</a><br/>
-        D.1.110 <a href="#feature-writingMode-vertical">#writingMode-vertical</a><br/>
-        D.1.111 <a href="#feature-writingMode-horizontal">#writingMode-horizontal</a><br/>
-        D.1.112 <a href="#feature-writingMode-horizontal-lr">#writingMode-horizontal-lr</a><br/>
-        D.1.113 <a href="#feature-writingMode-horizontal-rl">#writingMode-horizontal-rl</a><br/>
-        D.1.114 <a href="#feature-zIndex">#zIndex</a><br/>
-    D.2 <a href="#feature-support">Feature Support</a><br/>
-E <a href="#extensions">Extensions</a><br/>
-    E.1 <a href="#extension-designations">Extension Designations</a><br/>
-F <a href="#profiles">Profiles</a><br/>
-    F.1 <a href="#profile-dfxp-transformation">DFXP Transformation Profile</a><br/>
-    F.2 <a href="#profile-dfxp-presentation">DFXP Presentation Profile</a><br/>
-    F.3 <a href="#profile-dfxp-full">DFXP Full Profile</a><br/>
-G <a href="#references">References</a><br/>
-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="#d3e17042">Element Derivation</a><br/>
-    J.2 <a href="#d3e17521">Attribute Derivation</a><br/>
-K <a href="#qa">QA Framework Compliance</a> (Non-Normative)<br/>
-    K.1 <a href="#d3e18389">Requirements</a><br/>
-    K.2 <a href="#d3e18553">Guidelines</a><br/>
-L <a href="#streaming">Streaming TTML Content</a> (Non-Normative)<br/>
-M <a href="#acknowledgments">Acknowledgments</a> (Non-Normative)<br/>
-</p></div><hr/><div class="body"><div class="div1">
-<h2><a name="intro" id="intro"/>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) 1.0
-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 potential presentation.</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>I 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;text&gt;</code> or 
-<code>&lt;textstream&gt;</code> media object element in a <a href="#smil21">[SMIL 2.1]</a> document. Certain properties of TTML support
-streamability of content, as described in <a href="#streaming"><b>L Streaming TTML Content</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>While TTML was not expressly designed for direct (embedded) integration into 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 document instance. 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="div2">
-<h3><a name="model" id="model"/>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 a 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.</p><table summary="HTML Table" id="model-graphic" class="example-images"><caption>Figure 1 – System Model</caption><tbody><tr><td><img src="images/model.png" alt="System Model"/></td></tr></tbody></table></div><div class="div2">
-<h3><a name="example" id="example"/>1.2 Document Example</h3><p>A TTML document instance 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 timing information.</p><table summary="HTML Table" id="dfxp-example-document-structure" 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><table summary="HTML Table" id="dfxp-example-metadata" 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.</p><p>In <a href="#dfxp-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><table summary="HTML Table" id="dfxp-example-styling" 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="#dfxp-example-layout"><b>Example Fragment – TTML Layout</b></a>, the region definition makes
-reference to style specification <code>s1</code> which allows all 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><table summary="HTML Table" id="dfxp-example-layout" 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 TTML document instance 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="#dfxp-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 as a parallel time
-container.</p><table summary="HTML Table" id="dfxp-example-body" 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="#dfxp-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
-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><table summary="HTML Table" id="dfxp-example-subtitle-1" 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><table summary="HTML Table" id="dfxp-example-subtitle-2" 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><table summary="HTML Table" id="dfxp-example-subtitle-3" 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><table summary="HTML Table" id="dfxp-example-subtitle-4" 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><table summary="HTML Table" id="dfxp-example-subtitle-5" 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 paragraph expressing each subtitle using a different style that overrides 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><table summary="HTML Table" id="dfxp-example-subtitle-6" 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 a paragraph right (end) justified in the
-inline progression direction.</p><table summary="HTML Table" id="dfxp-example-subtitle-7" 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><table summary="HTML Table" id="dfxp-example-subtitle-8" 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><table summary="HTML Table" id="dfxp-example-subtitle-9" 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 document instance. 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 name="definitions" id="definitions"/>2 Definitions</h2><div class="div2">
-<h3><a name="acronyms" id="acronyms"/>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 name="terms" id="terms"/>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
-Set</em>s <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
-item as defined by <a href="#infoset">[XML InfoSet]</a>, §2.3.</p></dd><dt class="label">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">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">Content Profile</dt><dd><p>A collection of features and extensions that are (or may be) employed by
-Timed Text Markup Language content.</p></dd><dt class="label">Content Region</dt><dd><p>A logical region into which rendered content is placed when modeling or
-performing presentation processing.</p></dd><dt class="label">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">Exchange Profile</dt><dd><p>A content profile that serves a set of needs
-for content interchange.</p></dd><dt class="label">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">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
-future revision of this specification).</p></dd><dt class="label">Processor</dt><dd><p>See <em>Content Processor</em>.</p></dd><dt class="label">Processor Profile</dt><dd><p>A collection of features and extensions that must or may be implemented (supported) by
-a content processor.</p></dd><dt class="label">Profile Definition Document</dt><dd><p>A document that defines a specific collection of features and extensions
-for which support is required or optional in a recipient content
-processor.</p></dd><dt class="label">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">Reduced XML Infoset</dt><dd><p>An XML Information Set <a href="#infoset">[XML InfoSet]</a> that satisfieds the
-constraints specify by <a href="#reduced-infoset"><b>A Reduced XML Infoset</b></a>.</p></dd><dt class="label">Root Container Region</dt><dd><p>A logical region that establishes a coordinate system into which
-content regions are placed and optionally clipped.</p></dd><dt class="label">Timed Text</dt><dd><p>Textual information that is intrinsically or extrinsically
-associated with timing information.</p></dd><dt class="label">Timed Text Markup Language</dt><dd><p>A content type that represents timed text media for the purpose of
-interchange among authoring systems.</p></dd><dt class="label">Timed Text Authoring System</dt><dd><p>A content authoring system capable of importing and exporting
-Timed Text Markup Language content.</p></dd></dl></div><div class="div2">
-<h3><a name="conventions" id="conventions"/>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>All normative syntactic definitions of XML representations and
-other related terms are depicted with a light orange background color
-and labeled as "XML Representation" or "Syntax Representation", such
-as in the following:</p><table summary="HTML Table" id="elt-syntax-example" class="syntax"><caption>XML Representation – Element Information Item: example</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;example
-  <span class="reqattr">count</span> = integer
-  size = (<em>large</em>|<em>medium</em>|<em>small</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
-attribute information item 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>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>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><table summary="HTML Table" id="example-fragment-1" 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></div></div><div class="div1">
-<h2><a name="conformance" id="conformance"/>3 Conformance</h2><p>This section specifies the general conformance requirements for
-TTML content and processors.</p><div class="div2">
-<h3><a name="conformance-content" id="conformance-content"/>3.1 Content Conformance</h3><p>A TTML document instance conforms to this specification if the following criteria are
-satisfied:</p><ol class="enumar"><li><p>When transporting a document instance in a context in which a MIME
-Media Type <a href="#mime-media">[MIME]</a> identifies the content type of the interchanged document
-instance, then the specified media type is
-<code>application/ttml+xml</code> in conformance with <a href="#rfc3023">[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-profiles"><b>5.2 Profiles</b></a>.</p></li><li><p>The document instance is or can be represented as a Reduced XML
-Infoset as defined by <a href="#reduced-infoset"><b>A Reduced XML Infoset</b></a>.</p></li><li><p>The Reduced XML
-Infoset that corresponds to the document instance is or can
-be associated with one of the TTML Abstract
-Document Types defined by
-<a href="#doctypes"><b>4 Document Types</b></a>.</p></li><li><p>The Reduced XML Infoset that corresponds to the document instance is a
-Valid Abstract Document Instance of the associated
-Abstract Document Type.</p></li><li><p>The Reduced XML Infoset 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 name="conformance-processor" id="conformance-processor"/>3.2 Processor Conformance</h3><div class="div3">
-<h4><a name="conformance-generic-processor" id="conformance-generic-processor"/>3.2.1 Generic Processor Conformance</h4><p>A TTML processor 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 Reduced XML
-Infoset representation of a conformant TTML document
-instance.</p></li><li><p>If a process does or can perform validation of a candidate TTML
-document instance, then it provides at least one mechanism to
-implicitly or explicitly associate the
-Reduced XML Infoset representation
-of a conformant TTML document instance with one of the
-TTML Abstract Document Types 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 TTML document instance
-unless the processor does not support some required
-(mandatory) feature specified or implied by a TTML content profile
-declared to apply to the document instance.</p></li><li><p>The processor supports all mandatory processing semantics defined by this specification.</p></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></li></ol></div><div class="div3">
-<h4><a name="conformance-transformation-processor" id="conformance-transformation-processor"/>3.2.2 Transformation Processor Conformance</h4><p>A TTML processor is a conformant TTML transformation processor 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 DFXP Transformation profile as specified
-by <a href="#profile-dfxp-transformation"><b>F.1 DFXP Transformation Profile</b></a>.</p></li></ol></div><div class="div3">
-<h4><a name="conformance-presentation-processor" id="conformance-presentation-processor"/>3.2.3 Presentation Processor Conformance</h4><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 DFXP Presentation profile as specified
-by <a href="#profile-dfxp-presentation"><b>F.2 DFXP Presentation Profile</b></a>.</p></li></ol></div></div><div class="div2">
-<h3><a name="claims" id="claims"/>3.3 Claims</h3><p>Any claim of compliance with respect to TTML content or processor
-conformance 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
-content or processor implementation. In particular, the statement must
-identify the utilized or supported TTML vocabulary profile(s) as
-defined by <a href="#vocabulary-profiles"><b>5.2 Profiles</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 TTML document instance 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="#parameter-attribute-profile"><b>6.2.8 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="#parameter-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>.</p></div></div><div class="div1">
-<h2><a name="doctypes" id="doctypes"/>4 Document Types</h2><p>This section defines the following TTML Abstract Document Types:</p><ul><li><p><a href="#dfxp-content-doctype"><b>4.1 DFXP Content</b></a></p></li></ul><p>Each abstract document type 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 Abstract Document Instance may be assessed in terms of validity,
-and is considered to be a Valid Abstract Document Instance 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 abstract document type, 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 Abstract Document Type, 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 1 – Namespaces</b></a>,</p></li></ol><p>then the document element is one of the document
-element types permitted by the associated abstract document type,
-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 abstract document type.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>While a conformant processor may not <em>a priori</em> reject a
-conformant document instance that adheres to a
-supported content profile, a given document instance may be
-constrained by the author or authoring tool to satisfy a more
-restrictive definition of validity.</p></div><div class="div2">
-<h3><a name="dfxp-content-doctype" id="dfxp-content-doctype"/>4.1 DFXP Content</h3><p>DFXP Content is an abstract document type 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 defines two types of normative schemas that may be used to validate a subset of
-conformant DFXP Content document instances:</p><ul><li><p><a href="#dfxp-schema-rnc"><b>B.1 Relax NG Schema</b></a></p></li><li><p><a href="#dfxp-schema-xsd"><b>B.2 XML Schema Definition (XSD) Schema</b></a></p></li></ul><p>The (root) document element of a DFXP Content document instance must be a
-<code>tt</code> element, as defined by <a href="#document-structure-vocabulary-tt"><b>7.1.1 tt</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The schemas included in this specification do not validate all syntactic constraints
-defined by this specification. In particular, performing validation with one of the above
-referenced schemas may result in a <em>false positive</em> indication of validity.
-However, with one exception, their
-use will not produce a <em>false negative</em> indication of validity
-when used with a compliant validating
-processor.</p><p>In exception to the above statement about false negatives,
-if the Relax NG schema included in this specification is used to validate a
-TTML Document containing elements in a foreign namespace and the <code>xml:id</code>
-attribute is used with any of those (foreign) elements,
-then an error will be reported even though such usage is permitted by this
-specification. In this case, the false negative arises 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 TTML Document to be
-based on an abstract document instance 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 TTML Document validity.</p></div></div></div><div class="div1">
-<h2><a name="vocabulary" id="vocabulary"/>5 Vocabulary</h2><p>This section defines the
-namespaces, profiles, and vocabulary (as an element an 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-profiles"><b>5.2 Profiles</b></a></p></li><li><p><a href="#vocabulary-overview"><b>5.3 Catalog</b></a></p></li></ul><div class="div2">
-<h3><a name="vocabulary-namespaces" id="vocabulary-namespaces"/>5.1 Namespaces</h3><p>The Timed Text Markup Language (TTML) employs a number of
-namespaces 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 document instance, it is not required that the default
-prefixes shown below are used. Any prefix or namespace binding that satisfies the constraints
-of XML Namespaces may be used that is associated with the specified namespace URI.</p></div><table summary="HTML Table" id="namespace-vocab-table" class="common"><caption>Table 1 – Namespaces</caption><col width="30%" 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 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>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 name="vocabulary-profiles" id="vocabulary-profiles"/>5.2 Profiles</h3><p>The Timed Text Markup Language (TTML) employs a number of
-standard, predefined profiles of its
-vocabulary and associated semantics.
-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="#profiles"><b>F Profiles</b></a>.</p><table summary="HTML Table" id="profile-vocab-table" class="common"><caption>Table 2 – Profiles</caption><col width="25%" span="1"/><tbody><tr><th>Name</th><th>Designator</th></tr><tr><td>DFXP Transformation</td><td><code>http://www.w3.org/ns/ttml/profile/dfxp-transformation</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 Full</td><td><code>http://www.w3.org/ns/ttml/profile/dfxp-full</code></td></tr></tbody></table><p/><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>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 Profile Definition Document.</p><p>The profile of TTML that must be supported by a
-TTML content processor in order to process a document
-instance is specified 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
-including one or more <code>ttp:profile</code>
-elements in the <code>head</code> element, in
-accordance with <a href="#parameter-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>.</p><p>If a <code>ttp:profile</code> element appears as a
-descendant of the <code>tt</code> element, then the <a href="#parameter-attribute-profile"><code>ttp:profile</code></a>
-attribute should not be specified on the <code>tt</code> element. If both
-a <code>ttp:profile</code> element and a <code>ttp:profile</code>
-attribute are present (in a given document instance), then the
-<code>ttp:profile</code> attribute must be ignored for the purpose of
-determining the declared profile requirements.</p><p>If more than one <code>ttp:profile</code> element appears in
-a TTML document instance, then all specified profiles apply
-simultaneously.  In such a case, if some feature or some extension is
-specified by one profile to be used (mandatory and enabled) and by
-another profile to be required (mandatory) or optional (voluntary),
-then that feature or extension must be considered to be used
-(mandatory and enabled); if some feature or some extension is
-specified by one profile to be merely required (mandatory) and by
-another profile to be optional (voluntary), then that feature or
-extension must be considered to be required (mandatory).</p><p>If neither
-<a href="#parameter-attribute-profile"><code>ttp:profile</code></a>
-attribute nor
-<a href="#parameter-vocabulary-profile"><code>ttp:profile</code></a>
-element is present in a TTML document instance, and if the document
-interchange context does not specify a profile,
-then the DFXP Transformation
-profile applies.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>It is intended that the <code>ttp:profile</code> attribute be used when
-the author wishes to reference one of the standard, predefined 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 TTML Profile Definition Document.
-However, it is not required that a conformant TTML content processor 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 document instance 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 required (mandatory) that was either not specified in the underlying, baseline
-profile or was specified as optional (voluntary) in the baseline profile.
-A predefined profile is subsetted by specifying some feature or extension to
-be optional (voluntary) that was specified as required 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>If a TTML document instance makes use of a feature defined by
-<a href="#feature-designations"><b>D.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 feature</em> or
-a <em>used feature</em>
-specification in one of its declared or
-referenced profiles.  If a TTML document instance makes use
-of an extension designatable by <a href="#extension-designations"><b>E.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 extension</em> or
-a <em>used extension</em> specification
-in one of its declared or referenced
-profiles.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A required or used feature
-specification is expressed directly (or indirectly by referring to a
-profile) by means of a <a href="#parameter-vocabulary-feature"><code>ttp:feature</code></a>
-element where the value of its <code>value</code> attribute is
-<code>required</code> or <code>use</code>,
-respectively.  A required or used
-extension specification is expressed directly (or indirectly by
-referring to a profile) by means of a <a href="#parameter-vocabulary-extension"><code>ttp:extension</code></a>
-element where the value of its <code>value</code> attribute is
-<code>required</code> or <code>use</code>,
-respectively.</p></div><p>An example of an author defined
-additive, derived profile of the DFXP Presentation
-profile is shown
-below in <a href="#dfxp-example-sub-profile"><b>Example Fragment – DFXP Additive Profile</b></a>.</p><table summary="HTML Table" id="dfxp-example-sub-profile" class="example"><caption>Example Fragment – DFXP 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="dfxp-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 DFXP 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-dfxp-presentation"><b>F.2 DFXP 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="div2">
-<h3><a name="vocabulary-overview" id="vocabulary-overview"/>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 DFXP Content. The extension catalog
-serves as a placeholder for extensions to the core vocabulary defined
-by TTML.</p><div class="div3">
-<h4><a name="core-vocabulary-overview" id="core-vocabulary-overview"/>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="#parameters"><b>6 Parameters</b></a></p></li><li><p><a href="#content"><b>7 Content</b></a></p></li><li><p><a href="#styling"><b>8 Styling</b></a></p></li><li><p><a href="#layout"><b>9 Layout</b></a></p></li><li><p><a href="#timing"><b>10 Timing</b></a></p></li><li><p><a href="#animation"><b>11 Animation</b></a></p></li><li><p><a href="#metadata"><b>12 Metadata</b></a></p></li></ul><p>The core element vocabulary specified for use with a TTML document
-instance is enumerated in
-<a href="#element-vocab-table"><b>Table 3 – Element Vocabulary</b></a>.</p><table summary="HTML Table" id="element-vocab-table" class="common"><caption>Table 3 – Element Vocabulary</caption><col width="25%" span="1"/><tbody><tr><th>Module</th><th>Elements</th></tr><tr><td>
-Animation
-</td><td>
-<a href="#animation-vocabulary-set">set</a>
-</td></tr><tr><td>
-Content
-</td><td>
-<a href="#document-structure-vocabulary-body">body</a>,
-<a href="#content-vocabulary-div">div</a>,
-<a href="#content-vocabulary-p">p</a>,
-<a href="#content-vocabulary-span">span</a>,
-<a href="#content-vocabulary-br">br</a>
-</td></tr><tr><td>
-Document
-</td><td>
-<a href="#document-structure-vocabulary-tt">tt</a>
-</td></tr><tr><td>
-Head
-</td><td>
-<a href="#document-structure-vocabulary-head">head</a>
-</td></tr><tr><td>
-Layout
-</td><td>
-<a href="#layout-vocabulary-layout">layout</a>,
-<a href="#layout-vocabulary-region">region</a>
-</td></tr><tr><td>
-Metadata
-</td><td>
-<a href="#metadata-vocabulary-metadata">metadata</a>
-</td></tr><tr><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-name">ttm:name</a>,
-<a href="#metadata-vocabulary-title">ttm:title</a>
-</td></tr><tr><td>Parameter Items</td><td><a href="#parameter-vocabulary-profile">ttp:profile</a>,
-<a href="#parameter-vocabulary-features">ttp:features</a>,
-<a href="#parameter-vocabulary-feature">ttp:feature</a>,
-<a href="#parameter-vocabulary-extensions">ttp:extensions</a>,
-<a href="#parameter-vocabulary-extension">ttp:extension</a>
-</td></tr><tr><td>
-Styling
-</td><td>
-<a href="#styling-vocabulary-styling">styling</a>,
-<a href="#styling-vocabulary-style">style</a>
-</td></tr></tbody></table><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 4 – Element Vocabulary Groups</b></a>.</p><table summary="HTML Table" id="element-vocab-group-table" class="common"><caption>Table 4 – Element Vocabulary Groups</caption><col width="25%" span="1"/><tbody><tr><th>Group</th><th>Elements</th></tr><tr><td>
-Animation.class
-</td><td>
-<a href="#animation-vocabulary-set">set</a>
-</td></tr><tr><td>
-Block.class
-</td><td>
-<a href="#content-vocabulary-div">div</a> |
-<a href="#content-vocabulary-p">p</a>
-</td></tr><tr><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>
-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-title">ttm:title</a>
-</td></tr><tr><td>Parameters.class</td><td><a href="#parameter-vocabulary-profile">ttp:profile</a></td></tr></tbody></table><p/><p>The attribute vocabulary specified for use with the core vocabulary
-catalog is enumerated in
-<a href="#attribute-vocab-table"><b>Table 5 – Attribute Vocabulary</b></a>.</p><table summary="HTML Table" id="attribute-vocab-table" class="common"><caption>Table 5 – Attribute Vocabulary</caption><col width="25%" span="1"/><tbody><tr><th>Module</th><th>Attributes</th></tr><tr><td>
-Core Attributes
-</td><td>
-<a href="#content-attribute-id">xml:id</a>,
-<a href="#content-attribute-lang">xml:lang</a>,
-<a href="#content-attribute-space">xml:space</a>
-</td></tr><tr><td>
-Layout
-</td><td>
-<a href="#layout-attribute-region">region</a>
-</td></tr><tr><td>
-Metadata Attributes
-</td><td>
-<a href="#metadata-attribute-agent">ttm:agent</a>,
-<a href="#metadata-attribute-role">ttm:role</a>
-</td></tr><tr><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-pixelAspectRatio">ttp:pixelAspectRatio</a>,
-<a href="#parameter-attribute-profile">ttp:profile</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><td>
-Styling
-</td><td>
-<a href="#style-attribute-style">style</a>
-</td></tr><tr><td>
-Styling Attributes
-</td><td>
-<a href="#style-attribute-backgroundColor">tts:backgroundColor</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-fontSize">tts:fontSize</a>,
-<a href="#style-attribute-fontStyle">tts:fontStyle</a>,
-<a href="#style-attribute-fontWeight">tts:fontWeight</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-showBackground">tts:showBackground</a>,
-<a href="#style-attribute-textAlign">tts:textAlign</a>,
-<a href="#style-attribute-textDecoration">tts:textDecoration</a>,
-<a href="#style-attribute-textOutline">tts:textOutline</a>,
-<a href="#style-attribute-unicodeBidi">tts:unicodeBidi</a>,
-<a href="#style-attribute-visibility">tts:visibility</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><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 – 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 name="extension-vocabulary-overview" id="extension-vocabulary-overview"/>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 TTML
-document instance may contain arbitrary namespace qualified
-elements that reside in any namespace other than those namespaces
-defined for use with this specification. Furthermore, a conforming TTML
-document instance 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 name="parameters" id="parameters"/>6 Parameters</h2><p>This section specifies the <em>parameters</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 processing context by means
-of which TTML content can be related to an external environment.</p><div class="div2">
-<h3><a name="parameter-element-vocabulary" id="parameter-element-vocabulary"/>6.1 Parameter Element Vocabulary</h3><p>The following elements, all defined in the TT Parameter
-Namespace, specify parametric information that applies to a document
-or a content processor:</p><ul><li><p><a href="#parameter-vocabulary-profile"><b>6.1.1 ttp:profile</b></a></p></li><li><p><a href="#parameter-vocabulary-features"><b>6.1.2 ttp:features</b></a></p></li><li><p><a href="#parameter-vocabulary-feature"><b>6.1.3 ttp:feature</b></a></p></li><li><p><a href="#parameter-vocabulary-extensions"><b>6.1.4 ttp:extensions</b></a></p></li><li><p><a href="#parameter-vocabulary-extension"><b>6.1.5 ttp:extension</b></a></p></li></ul><div class="div3">
-<h4><a name="parameter-vocabulary-profile" id="parameter-vocabulary-profile"/>6.1.1 ttp:profile</h4><p>The <code>ttp:profile</code> element is used to specify a collection of
-used (mandatory and enabled), required (mandatory),
-and optional (voluntary) features and extensions that must or
-may be supported by a TTML content processor in order to process a TTML
-document that makes use (or may make use) of such features and
-extensions.</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>D 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 uses of the <code>ttp:profile</code> element:</p><ul><li><p>as a child of the <code>head</code> element within a TTML document
-instance;</p></li><li><p>as the root element of a TTML Profile Definition document
-instance;</p></li></ul><p>When a <code>tt:profile</code> element appears within a TTML document
-instance, its purpose is to express authorial intentions about which
-features and extensions must or may be supported by a recipient
-content processor. In addition, the element indirectly expresses
-information about the set of features or extensions that are (or may
-expected to be) used by the document instance.</p><p>When a <code>tt:profile</code> element is used by a TTML
-Profile Definition document instance, it serves to publish a machine
-readable specification of a specific TTML content profile, of which
-this specification defines three such Profile Definition Documents in
-<a href="#profiles"><b>F Profiles</b></a>.</p><p>The <code>ttp:profile</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group, followed by
-zero or more <code>ttp:features</code> elements, followed by
-zero or more <code>ttp:extensions</code> elements.</p><table summary="HTML Table" id="elt-syntax-parameter-profile" class="syntax"><caption>XML Representation – Element Information Item: ttp:profile</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:profile
-  use = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#parameter-vocabulary-features">ttp:features</a>*, <a href="#parameter-vocabulary-extensions">ttp:extensions</a>*
-&lt;/ttp:profile&gt;
-</pre></div>
-</td></tr></tbody></table><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-profiles"><b>5.2 Profiles</b></a>. In this case,
-the profile designator must refer to (1) a standard, predefined
-TTML Profile Definition Document as defined by <a href="#profiles"><b>F Profiles</b></a>,
-or (2) a dereferenceable resource representing a valid TTML Profile Definition
-document instance. In either case, the referenced profile serves as the
-baseline profile of the specifying <code>ttp:profile</code> element.</p><p>If the <code>use</code> attribute is not specified, then the baseline
-profile 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 collection of features and extensions of a profile are determined according
-to the following ordered rules:</p><ol class="enumar"><li><p>initialize the features and extensions of the profile to the empty
-set;</p></li><li><p>if a <code>use</code> attribute is present, then augment the profile
-with the set of features and extensions specified by the referenced
-baseline profile;</p></li><li><p>for each <code>ttp:feature</code> and <code>ttp:extension</code> element
-descendant of the <code>ttp:profile</code> element, using a post-order
-traversal, merge the specified feature or extension with the features
-and extensions of the profile, where merging a feature or extension
-entails replacing an existing feature or extension specification, if
-it already exists, or adding a new feature or extension specification,
-if it does not yet exist in the profile;</p></li></ol><p>A conformant TTML processor is not required to be able to
-dereference a TTML Profile Definition Document that is not one of the
-standard, predefined profiles defined by <a href="#profiles"><b>F Profiles</b></a>.  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 TTML
-Profile Definition Document, 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 TTML document instance due to the inability to
-reference a non-standard TTML Profile Definition Document, 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><table summary="HTML Table" id="parameter-vocabulary-profile-example-1" class="example"><caption>Example Fragment – ttp:profile</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:profile use="dfxp-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 DFXP 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 name="parameter-vocabulary-features" id="parameter-vocabulary-features"/>6.1.2 ttp:features</h4><p>The <code>ttp:features</code> element is a container element used to group
-infomation about feature support requirements.</p><p>The <code>ttp:features</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group, followed by
-zero or more <code>ttp:feature</code> elements.</p><table summary="HTML Table" id="elt-syntax-parameter-features" class="syntax"><caption>XML Representation – Element Information Item: ttp:features</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:features
-  xml:base = string : <em>TT Feature Namespace</em>
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#parameter-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>D.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 name="parameter-vocabulary-feature" id="parameter-vocabulary-feature"/>6.1.3 ttp:feature</h4><p>The <code>ttp:feature</code> element is used to specify
-infomation about support requirements for a particular feature.</p><p>The children of the <code>ttp:feature</code> element must express a non-empty
-sequence of character information items that adheres to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17.</p><table summary="HTML Table" id="elt-syntax-parameter-feature" class="syntax"><caption>XML Representation – Element Information Item: ttp:feature</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:feature
-  value = (optional|required|use) : required
-  <a href="#content-attribute-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>If the URI expressed by the content of the <code>ttp:feature</code>
-element 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>D.1 Feature Designations</b></a>.</p><p>If
-the URI expressed by the content of the <code>ttp:feature</code> element
-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 whether a conforming TTML
-processor must or may implement the designated feature in order to
-process the document. If the value of the <code>value</code> attribute
-is <code>optional</code>, then the processor need
-not implement or otherwise support the feature in order to process the
-document; if the value is <code>required</code>, then the processor
-must implement or otherwise support the feature in order to process
-the document; if the value is
-<code>use</code>, then the processor must both (1) implement or
-otherwise support the feature and (2) enable (activate) use of the
-feature.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The default value of the <code>value</code> attribute is
-<code>required</code>, as indicated in the above element information
-item definition. Therefore, if a <code>value</code> attribute is not
-specified on a <code>ttp:feature</code> element, it is equivalent to
-specifying that support for the feature is required.</p></div><p>If the value of the <code>value</code> attribute is
-<code>required</code> or <code>use</code>,
-and if the TTML processor implementation does
-not support the feature, 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 TTML document instance due to the specification of a
-required, but unsupported feature by this element, 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>If the value of the <code>value</code> attribute is
-<code>optional</code>, and if the TTML processor implementation does
-not support the feature, then it may further process the document even
-in the case that some use of the feature is present in the document.
-In the case of actual use of a feature designated as optional, the
-default semantics associated with that feature apply; that is, the
-processor may behave as if the feature were not actually used or
-referenced by the document. Notwithstanding the above, the syntactic
-presence or reference to an optional feature by a document must not be
-considered to be a violation of document validity or a barrier to
-further processing if the syntactic expression is well-formed and
-valid.</p><p>The <code>ttp:feature</code> element is illustrated by the following example.</p><table summary="HTML Table" id="parameter-vocabulary-feature-example-1" 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/dfxp-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>
-  &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 DFXP presentation profile is used as the
-baseline profile. This baseline profile is then modified by two
-<code>ttp:feature</code> elements in order to
-superset the baseline profile (since neither
-<code>#fontStyle-italic</code> nor <code>#textDecoration-under</code>
-are required by the DFXP presentation profile).  
-</p><p>The effect of this example is to express authorial intentions that
-italic font style and text underlining must be
-supported.</p></div></div><div class="div3">
-<h4><a name="parameter-vocabulary-extensions" id="parameter-vocabulary-extensions"/>6.1.4 ttp:extensions</h4><p>The <code>ttp:extensions</code> element is a container element used to group
-infomation about extension support requirements.</p><p>The <code>ttp:extensions</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group, followed by
-zero or more <code>ttp:extension</code> elements.</p><table summary="HTML Table" id="elt-syntax-parameter-extensions" class="syntax"><caption>XML Representation – Element Information Item: ttp:extensions</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:extensions
-  xml:base = string : <em>TT Extension Namespace</em>
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#parameter-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>E.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 name="parameter-vocabulary-extension" id="parameter-vocabulary-extension"/>6.1.5 ttp:extension</h4><p>The <code>ttp:extension</code> element is used to specify
-infomation about support requirements for a particular extension.</p><p>The children of the <code>ttp:extension</code> element must express a non-empty
-sequence of character information items that adheres to the
-<code>xsd:anyURI</code> data type defined by <a href="#xsd-2">[XML Schema Part 2]</a>,
-§3.2.17.</p><table summary="HTML Table" id="elt-syntax-parameter-extension" class="syntax"><caption>XML Representation – Element Information Item: ttp:extension</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttp:extension
-  value = (optional|required|use) : required
-  <a href="#content-attribute-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>If the URI expressed by the content of the <code>ttp:extension</code>
-element 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>E.1 Extension Designations</b></a>.</p><p>If the URI expressed by the content of the
-<code>ttp:feature</code> element 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 whether a conforming TTML
-processor must or may implement the designated extension in order to
-process the document. If the value of the <code>value</code> attribute
-is <code>optional</code>, then the processor need
-not implement or otherwise support the extension in order to process the
-document; if the value is <code>required</code>, then the processor
-must implement or otherwise support the extension in order to process
-the document; if the value is
-<code>use</code>, then the processor must both (1) implement or
-otherwise support the extension and (2) enable (activate) use of the
-extension.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The default value of the <code>value</code> attribute is
-<code>required</code>, as indicated in the above element information
-item definition. Therefore, if a <code>value</code> attribute is not
-specified on a <code>ttp:extension</code> element, it is equivalent to
-specifying that support for the extension is required.</p></div><p>If the value of the <code>value</code> attribute is
-<code>required</code> or <code>use</code>,
-and if the TTML processor implementation does not support the
-extension, 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 TTML document instance due to the specification of a
-required, but unsupported extension by this element, 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>If the value of the <code>value</code> attribute is
-<code>optional</code>, and if the TTML processor implementation does
-not support the extension, then it may further process the document even
-in the case that some use of the extension is present in the document.
-In the case of actual use of an extension designated as optional, the
-default semantics associated with that extension apply; that is, the
-processor may behave as if the extension were not actually used or
-referenced by the document. Notwithstanding the above, the syntactic
-presence or reference to an optional extension by a document must not be
-considered to be a violation of document validity or a barrier to
-further processing if the syntactic expression is well-formed and
-valid.</p><p>The <code>ttp:extension</code> element is illustrated by the following example.</p><table summary="HTML Table" id="parameter-vocabulary-extension-example-1" 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://foo.bar.example.org/ttaf1/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 DFXP 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 DFXP transformation profile and
-must also support and use an extension defined by a third party.</p></div></div></div><div class="div2">
-<h3><a name="parameter-attribute-vocabulary" id="parameter-attribute-vocabulary"/>6.2 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>6.2.1 ttp:cellResolution</b></a></p></li><li><p><a href="#parameter-attribute-clockMode"><b>6.2.2 ttp:clockMode</b></a></p></li><li><p><a href="#parameter-attribute-dropMode"><b>6.2.3 ttp:dropMode</b></a></p></li><li><p><a href="#parameter-attribute-frameRate"><b>6.2.4 ttp:frameRate</b></a></p></li><li><p><a href="#parameter-attribute-frameRateMultiplier"><b>6.2.5 ttp:frameRateMultiplier</b></a></p></li><li><p><a href="#parameter-attribute-markerMode"><b>6.2.6 ttp:markerMode</b></a></p></li><li><p><a href="#parameter-attribute-pixelAspectRatio"><b>6.2.7 ttp:pixelAspectRatio</b></a></p></li><li><p><a href="#parameter-attribute-profile"><b>6.2.8 ttp:profile</b></a></p></li><li><p><a href="#parameter-attribute-subFrameRate"><b>6.2.9 ttp:subFrameRate</b></a></p></li><li><p><a href="#parameter-attribute-tickRate"><b>6.2.10 ttp:tickRate</b></a></p></li><li><p><a href="#parameter-attribute-timeBase"><b>6.2.11 ttp:timeBase</b></a></p></li></ul><p>Unless explicitly stated otherwise, linear white-space (LWSP) may
-appear between tokens of a value of a TT Parameter.</p><div class="div3">
-<h4><a name="parameter-attribute-cellResolution" id="parameter-attribute-cellResolution"/>6.2.1 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 root container region
-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><table summary="HTML Table" id="parameter-attribute-cellResolution-syntax" 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="#cea608c">[CEA-608-C]</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></div><div class="div3">
-<h4><a name="parameter-attribute-clockMode" id="parameter-attribute-clockMode"/>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
-specification of time expression syntax.</p></div><p>If specified, the value of this attribute must adhere to the following syntax:</p><table summary="HTML Table" id="parameter-attribute-clockMode-syntax" 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>6.2.11 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 name="parameter-attribute-dropMode" id="parameter-attribute-dropMode"/>6.2.3 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>6.2.11 ttp:timeBase</b></a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><table summary="HTML Table" id="parameter-attribute-dropMode-syntax" 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>6.2.11 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>01:10:00:04</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 name="parameter-attribute-frameRate" id="parameter-attribute-frameRate"/>6.2.4 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 document instance 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><table summary="HTML Table" id="parameter-attribute-frameRate-syntax" 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 document instance is used to
-interpret time expressions that are expressed in <em>frames</em>
-as defined by <a href="#timing-value-timeExpression"><b>10.3.1 &lt;timeExpression&gt;</b></a>.</p><p>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><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 name="parameter-attribute-frameRateMultiplier" id="parameter-attribute-frameRateMultiplier"/>6.2.5 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><table summary="HTML Table" id="parameter-attribute-frameRateMultiplier-syntax" 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 name="parameter-attribute-markerMode" id="parameter-attribute-markerMode"/>6.2.6 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>6.2.11 ttp:timeBase</b></a>.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><table summary="HTML Table" id="parameter-attribute-markerMode-syntax" 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>6.2.11 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>continuous</code>.</p><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>discontinuous</code> applies, then time
-expressions must not be converted to either media time or real time
-coordinates, arithmetical operators (addition, multiplication) are not
-defined on time expressions, and, consequently, any 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 some external synchronization
-context 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 name="parameter-attribute-pixelAspectRatio" id="parameter-attribute-pixelAspectRatio"/>6.2.7 ttp:pixelAspectRatio</h4><p>The <code>ttp:pixelAspectRatio</code> attribute may be used by a content author
-to express the aspect ratio of non-square pixels in the production of content that
-makes use of pixel coordinates.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><table summary="HTML Table" id="parameter-attribute-pixelAspectRatio-syntax" class="syntax"><caption>Syntax Representation – ttp:pixelAspectRatio</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttp:pixelAspectRatio
-  : width height                            // <em>width</em> != 0; <em>height</em> != 0
-
-width | height
-  : <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 width and height 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 class="note"><p class="prefix"><b>Note:</b></p><p>This parameter may be used by a content transcoder or translator in
-order to convert pixel measurements between different pixel aspect
-ratios while still maintaining authorial layout intentions.</p></div></div><div class="div3">
-<h4><a name="parameter-attribute-profile" id="parameter-attribute-profile"/>6.2.8 ttp:profile</h4><p>The <code>ttp:profile</code> attribute may be used by a content author
-to express the profile of the Timed Text Markup Language (TTML) used
-in a document instance.</p><p>If specified, the value of this 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, further, must specify a
-profile designator in accordance with
-<a href="#vocabulary-profiles"><b>5.2 Profiles</b></a>.</p><p>A <code>ttp:profile</code>
-attribute is considered to be significant only when specified on the
-<code>tt</code> element.</p></div><div class="div3">
-<h4><a name="parameter-attribute-subFrameRate" id="parameter-attribute-subFrameRate"/>6.2.9 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 document instance 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><table summary="HTML Table" id="parameter-attribute-subFrameRate-syntax" 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 document instance is used to
-interpret time expressions that are expressed in <em>sub-frames</em>
-as defined by <a href="#timing-value-timeExpression"><b>10.3.1 &lt;timeExpression&gt;</b></a>.</p><p>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><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 name="parameter-attribute-tickRate" id="parameter-attribute-tickRate"/>6.2.10 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 document instance 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><table summary="HTML Table" id="parameter-attribute-tickRate-syntax" 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 document instance 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>10.3.1 &lt;timeExpression&gt;</b></a>.</p><p>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><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 name="parameter-attribute-timeBase" id="parameter-attribute-timeBase"/>6.2.11 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 document instance.</p><p>If specified, the value of this attribute must adhere to the following syntax:</p><table summary="HTML Table" id="parameter-attribute-timeBase-syntax" 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 document instance is to be synchronized, or it may
-be the content of a document instance 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, 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 document instance 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>6.2.6 ttp:markerMode</b></a> and <a href="#parameter-attribute-dropMode"><b>6.2.3 ttp:dropMode</b></a>, respectively.</p><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 document instance 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 document instance, the interpretation of time expressions
-is uniform throughout the document instance.</p></div><p>When operating with the <code>clock</code> time base,
-the expression <em>media time</em> as used in this specification is
-to be interpreted as the real-time clock selected by
-<a href="#parameter-attribute-clockMode"><b>6.2.2 ttp:clockMode</b></a>.</p></div></div></div><div class="div1">
-<h2><a name="content" id="content"/>7 Content</h2><p>This section specifies the <em>content</em> matter of the core
-vocabulary catalog.</p><div class="div2">
-<h3><a name="content-element-vocabulary" id="content-element-vocabulary"/>7.1 Content Element Vocabulary</h3><p>The following elements specify the structure and principal content aspects of a
-document instance:</p><ul><li><p><a href="#document-structure-vocabulary-tt"><b>7.1.1 tt</b></a></p></li><li><p><a href="#document-structure-vocabulary-head"><b>7.1.2 head</b></a></p></li><li><p><a href="#document-structure-vocabulary-body"><b>7.1.3 body</b></a></p></li><li><p><a href="#content-vocabulary-div"><b>7.1.4 div</b></a></p></li><li><p><a href="#content-vocabulary-p"><b>7.1.5 p</b></a></p></li><li><p><a href="#content-vocabulary-span"><b>7.1.6 span</b></a></p></li><li><p><a href="#content-vocabulary-br"><b>7.1.7 br</b></a></p></li></ul><div class="div3">
-<h4><a name="document-structure-vocabulary-tt" id="document-structure-vocabulary-tt"/>7.1.1 tt</h4><p>The <code>tt</code> element serves as the root document element of a document
-instance.</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><table summary="HTML Table" id="elt-syntax-tt" class="syntax"><caption>XML Representation – Element Information Item: tt</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt
-  <a href="#style-attribute-extent">tts:extent</a> = string
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang"><span class="reqattr">xml:lang</span></a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>) : default
-  {<em>any attribute in TT Parameter 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 temporal beginning and ending of a document instance represented by a
-<code>tt</code> element is defined in relationship with some external
-application or presentation context. The temporal interval defined by
-these points is referred to subsequently as the <em>external time interval</em>.
-</p><p>A document instance has an implicit duration that is equal to the
-implicit duration of the <code>body</code> element of the document, if present, or zero,
-if not present.</p><p>If the <code>tts:extent</code> attribute is specified on the <code>tt</code>
-element, then it must adhere to <a href="#style-attribute-extent"><b>8.2.7 tts:extent</b></a>, in which case it
-specifies the spatial extent of the root container region in
-which content regions are located and presented. If no <code>tts:extent</code>
-attribute is specified, then the spatial extent of the root container region is
-considered to be determined by the external authoring or presentation
-context. The root container origin is determined by the external
-authoring context.</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 document instance.</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 name="document-structure-vocabulary-head" id="document-structure-vocabulary-head"/>7.1.2 head</h4><p>The <code>head</code> element is a container element used to group
-header matter, including metadata,
-profile, styling, and layout information.</p><p>The <code>head</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group,
-followed by zero or more elements in the
-<code>Parameters.class</code> element group,
-followed by zero or one <code>styling</code> element,
-followed by zero or one <code>layout</code> element.</p><p>Any metadata specified by children in the <code>Metadata.class</code>
-element group applies semantically to the document instance 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 document instance as a
-whole, and not just the <code>head</code> element.</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
-content elements.</p><p>A <code>layout</code> child element is used to specify layout constructs that
-are referenced by content elements.</p><table summary="HTML Table" id="elt-syntax-head" class="syntax"><caption>XML Representation – Element Information Item: head</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;head
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">Parameters.class</a>*, <a href="#styling-vocabulary-styling">styling</a>?, <a href="#layout-vocabulary-layout">layout</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 external time interval.</p></div><div class="div3">
-<h4><a name="document-structure-vocabulary-body" id="document-structure-vocabulary-body"/>7.1.3 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 <code>Metadata.class</code> element group,
-followed by zero or more
-elements in the <code>Animation.class</code> element group,
-followed by
-zero or more <code>div</code> elements.</p><p>Any metadata specified by children in the <code>Metadata.class</code>
-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 <code>Animation.class</code>
-element group apply semantically to the <code>body</code> element.</p><table summary="HTML Table" id="elt-syntax-body" class="syntax"><caption>XML Representation – Element Information Item: body</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;body
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&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-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">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 begin
-point of the external time interval. Similarly, if the end point of this interval remains unspecified, then the
-end point is interpreted as the end point of the external time interval.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A TTML document instance 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 begin and
-end time of the external time interval.</p><p>If the external time interval is shorter than the computed duration of the
-<code>body</code> element, then the active time interval of a document instance is
-truncated to the active end point of the external time interval.</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 document instance are available for style inheritance by
-descendant content elements 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 name="content-vocabulary-div" id="content-vocabulary-div"/>7.1.4 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 <code>Metadata.class</code> element group,
-followed by zero or more
-elements in the <code>Animation.class</code> element group,
-followed by
-zero or more
-<code>div</code> or 
-<code>p</code> elements.</p><p>Any metadata specified by children in the <code>Metadata.class</code>
-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 <code>Animation.class</code>
-element group apply semantically to the <code>div</code> element.</p><table summary="HTML Table" id="elt-syntax-div" class="syntax"><caption>XML Representation – Element Information Item: div</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;div
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&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-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">Animation.class</a>*, <a href="#element-vocab-group-table">Block.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 document instance
-are available for style inheritance by descendant content elements 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>div</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p></div><div class="div3">
-<h4><a name="content-vocabulary-p" id="content-vocabulary-p"/>7.1.5 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 <code>Metadata.class</code> element group,
-followed by zero or more
-elements in the <code>Animation.class</code> element group,
-followed by
-zero or more
-<code>span</code> element,
-<code>br</code> element,
-or text nodes interpreted as anonymous spans.</p><p>Any metadata specified by children in the <code>Metadata.class</code>
-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 <code>Animation.class</code>
-element group apply semantically to the <code>p</code> element.</p><table summary="HTML Table" id="elt-syntax-p" class="syntax"><caption>XML Representation – Element Information Item: p</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;p
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&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-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">Animation.class</a>*, <a href="#element-vocab-group-table">Inline.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 document instance are available for style inheritance by
-descendant content elements such as <code>span</code> and
-<code>br</code>.</p></div><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 character information items, 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><div class="div3">
-<h4><a name="content-vocabulary-span" id="content-vocabulary-span"/>7.1.6 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 <code>Metadata.class</code> element group,
-followed by zero or more
-elements in the <code>Animation.class</code> element group,
-followed by
-zero or more
-<code>span</code> elements,
-<code>br</code> elements,
-or text nodes interpreted as anonymous spans.</p><p>Any metadata specified by children in the <code>Metadata.class</code>
-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 <code>Animation.class</code>
-element group apply semantically to the <code>span</code> element.</p><table summary="HTML Table" id="elt-syntax-span" class="syntax"><caption>XML Representation – Element Information Item: span</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;span
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&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-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">Animation.class</a>*, <a href="#element-vocab-group-table">Inline.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 document instance are available for style inheritance by
-descendant content elements 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></div><div class="div3">
-<h4><a name="content-vocabulary-br" id="content-vocabulary-br"/>7.1.7 br</h4><p>The <code>br</code> element denotes an explicit line break.</p><table summary="HTML Table" id="elt-syntax-br" class="syntax"><caption>XML Representation – Element Information Item: br</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;br
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">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 ASCII control code
-<code>CR</code>
-followed by the control code <code>NL</code> 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></div></div><div class="div2">
-<h3><a name="content-attribute-vocabulary" id="content-attribute-vocabulary"/>7.2 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-id"><b>7.2.1 xml:id</b></a></p></li><li><p><a href="#content-attribute-lang"><b>7.2.2 xml:lang</b></a></p></li><li><p><a href="#content-attribute-space"><b>7.2.3 xml:space</b></a></p></li></ul><div class="div3">
-<h4><a name="content-attribute-id" id="content-attribute-id"/>7.2.1 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 name="content-attribute-lang" id="content-attribute-lang"/>7.2.2 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.</p></div><div class="div3">
-<h4><a name="content-attribute-space" id="content-attribute-space"/>7.2.3 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.</p><p>The semantics of the value <code>default</code> are fixed to mean that
-when performing presentation processing of a document instance as
-described by <a href="#semantics-region-layout-step-2"><b>9.3.3 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></div></div><div class="div1">
-<h2><a name="styling" id="styling"/>8 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 TTML documents in any particular way; 
-    but an implementation of this model by a TTML Presentation Processor
-    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 intended effect of the attributes in this section 
-    are to be compatible with  the layout model of XSL. Presentation agents may however 
-    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 name="styling-element-vocabulary" id="styling-element-vocabulary"/>8.1 Styling Element Vocabulary</h3><p>The following elements specify the structure and principal styling aspects of a
-document instance:</p><ul><li><p><a href="#styling-vocabulary-styling"><b>8.1.1 styling</b></a></p></li><li><p><a href="#styling-vocabulary-style"><b>8.1.2 style</b></a></p></li></ul><div class="div3">
-<h4><a name="styling-vocabulary-styling" id="styling-vocabulary-styling"/>8.1.1 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 <code>Metadata.class</code> element group, followed by
-zero or more <code>style</code> elements.</p><table summary="HTML Table" id="elt-syntax-styling" class="syntax"><caption>XML Representation – Element Information Item: styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;styling
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</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 external time interval.</p></div><div class="div3">
-<h4><a name="styling-vocabulary-style" id="styling-vocabulary-style"/>8.1.2 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>8.4.4.2 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><table summary="HTML Table" id="elt-syntax-style" class="syntax"><caption>XML Representation – Element Information Item: style</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;style
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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> EMPTY
-&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>8.4.1.2 Referential Styling</b></a> and <a href="#semantics-style-association-chained-referential"><b>8.4.1.3 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><div class="div2">
-<h3><a name="styling-attribute-vocabulary" id="styling-attribute-vocabulary"/>8.2 Styling Attribute Vocabulary</h3><p>This section defines the <a href="#style-attribute-style"><b>8.2.1 style</b></a> attribute used
-with both style definition elements as well as content 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 content elements
-that support inline style specifications:</p><ul><li><p><a href="#style-attribute-backgroundColor"><b>8.2.2 tts:backgroundColor</b></a></p></li><li><p><a href="#style-attribute-color"><b>8.2.3 tts:color</b></a></p></li><li><p><a href="#style-attribute-direction"><b>8.2.4 tts:direction</b></a></p></li><li><p><a href="#style-attribute-display"><b>8.2.5 tts:display</b></a></p></li><li><p><a href="#style-attribute-displayAlign"><b>8.2.6 tts:displayAlign</b></a></p></li><li><p><a href="#style-attribute-extent"><b>8.2.7 tts:extent</b></a></p></li><li><p><a href="#style-attribute-fontFamily"><b>8.2.8 tts:fontFamily</b></a></p></li><li><p><a href="#style-attribute-fontSize"><b>8.2.9 tts:fontSize</b></a></p></li><li><p><a href="#style-attribute-fontStyle"><b>8.2.10 tts:fontStyle</b></a></p></li><li><p><a href="#style-attribute-fontWeight"><b>8.2.11 tts:fontWeight</b></a></p></li><li><p><a href="#style-attribute-lineHeight"><b>8.2.12 tts:lineHeight</b></a></p></li><li><p><a href="#style-attribute-opacity"><b>8.2.13 tts:opacity</b></a></p></li><li><p><a href="#style-attribute-origin"><b>8.2.14 tts:origin</b></a></p></li><li><p><a href="#style-attribute-overflow"><b>8.2.15 tts:overflow</b></a></p></li><li><p><a href="#style-attribute-padding"><b>8.2.16 tts:padding</b></a></p></li><li><p><a href="#style-attribute-showBackground"><b>8.2.17 tts:showBackground</b></a></p></li><li><p><a href="#style-attribute-textAlign"><b>8.2.18 tts:textAlign</b></a></p></li><li><p><a href="#style-attribute-textDecoration"><b>8.2.19 tts:textDecoration</b></a></p></li><li><p><a href="#style-attribute-textOutline"><b>8.2.20 tts:textOutline</b></a></p></li><li><p><a href="#style-attribute-unicodeBidi"><b>8.2.21 tts:unicodeBidi</b></a></p></li><li><p><a href="#style-attribute-visibility"><b>8.2.22 tts:visibility</b></a></p></li><li><p><a href="#style-attribute-wrapOption"><b>8.2.23 tts:wrapOption</b></a></p></li><li><p><a href="#style-attribute-writingMode"><b>8.2.24 tts:writingMode</b></a></p></li><li><p><a href="#style-attribute-zIndex"><b>8.2.25 tts:zIndex</b></a></p></li></ul><p>Unless explicitly stated otherwise, linear white-space (LWSP) may
-appear between tokens of a value of a TT
-Style or TT Style Extension
-Property.</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>A style property may be expressed as a specified attribute on any content
-element 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="div3">
-<h4><a name="style-attribute-style" id="style-attribute-style"/>8.2.1 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
-specified
-style 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="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li><li><p><a href="#styling-vocabulary-style"><code>style</code></a></p></li></ul><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>8.4.1.2 Referential Styling</b></a> and <a href="#semantics-style-association-chained-referential"><b>8.4.1.3 Chained Referential Styling</b></a>, for
-further information on its semantics.</p></div></div><div class="div3">
-<h4><a name="style-attribute-backgroundColor" id="style-attribute-backgroundColor"/>8.2.2 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><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><table summary="HTML Table" id="style-property-details-backgroundColor" class="common"><col width="25%" 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</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><table summary="HTML Table" id="style-attribute-backgroundColor-example-1" 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/><table summary="HTML Table" id="style-attribute-backgroundColor-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-color" id="style-attribute-color"/>8.2.3 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><table summary="HTML Table" id="style-property-details-color" class="common"><col width="25%" 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</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 presentation processor
-should use an initial value that is highly contrastive to the
-background color of the root container region.</p><p>The <code>tts:color</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-color-example-1" 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/><table summary="HTML Table" id="style-attribute-color-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-direction" id="style-attribute-direction"/>8.2.4 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><table summary="HTML Table" id="style-property-details-direction" class="common"><col width="25%" 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 specified value of this attribute is not supported,
-then a presentation processor must ignore the attribute.</p><p>The <code>tts:direction</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-direction-example-1" 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/><table summary="HTML Table" id="style-attribute-direction-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-display" id="style-attribute-display"/>8.2.5 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><table summary="HTML Table" id="style-property-details-display" class="common"><col width="25%" 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><table summary="HTML Table" id="style-attribute-display-example-1" 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/><table summary="HTML Table" id="style-attribute-display-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-displayAlign" id="style-attribute-displayAlign"/>8.2.6 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><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><table summary="HTML Table" id="style-property-details-displayAlign" class="common"><col width="25%" 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 specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>before</code> were specified.</p><p>The <code>tts:displayAlign</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-displayAlign-example-1" 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/><table summary="HTML Table" id="style-attribute-displayAlign-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-extent" id="style-attribute-extent"/>8.2.7 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
-(which may be the root container 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><table summary="HTML Table" id="style-property-details-extent" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</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 root container region</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute consists of two <a href="#style-value-length">&lt;length&gt;</a>
-specifications, then they must be interpreted as <em>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>If the value of this attribute is <code>auto</code>, then the initial value
-of the style property must be considered to be the same as the root container extent.
-</p><p>
-The root container extent is determined either by a
-<code>tts:extent</code> specified on the <code>tt</code> element, if
-present, or by the external authoring context, 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 specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>auto</code> were specified.</p><p>The <code>tts:extent</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-extent-example-1" 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/><table summary="HTML Table" id="style-attribute-extent-example-1-images" 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 name="style-attribute-fontFamily" id="style-attribute-fontFamily"/>8.2.8 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><table summary="HTML Table" id="style-property-details-fontFamily" class="common"><col width="25%" 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>
- (<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-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>8.3.6 &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 specified font family is not available, then a
-presentation processor must attempt to map the specified font family
-to an available font family that has similar typographic
-characteristics, or, in the absence of such a mapping, it must
-interpret the font family as if the value <code>default</code> were
-specified.</p><p>The <code>tts:fontFamily</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-fontFamily-example-1" 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/><table summary="HTML Table" id="style-attribute-fontFamily-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-fontSize" id="style-attribute-fontSize"/>8.2.9 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, where font size is interpreted as a
-scaling transform to the font's design EM square.</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><table summary="HTML Table" id="style-property-details-fontSize" class="common"><col width="25%" 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-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to parent element's font size</td></tr><tr><td><em>Animatable:</em></td><td>discrete</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><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 specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>1c</code> were specified.</p><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>8.3.9 &lt;length&gt;</b></a>.</p></div><p>The <code>tts:fontSize</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-fontSize-example-1" 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/><table summary="HTML Table" id="style-attribute-fontSize-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-fontStyle" id="style-attribute-fontStyle"/>8.2.10 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><table summary="HTML Table" id="style-property-details-fontStyle" class="common"><col width="25%" 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-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>
-denote a shear transformation (at an unspecified
-angle) in the inline progression dimension.</p><p>If a specified font style is not available, then a
-presentation processor must attempt to map the specified font style
-to an available font style that has similar typographic
-characteristics, or, in the absence of such a mapping, it must
-interpret the font style as if the value <code>normal</code> were
-specified.</p><p>The <code>tts:fontStyle</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-fontStyle-example-1" 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/><table summary="HTML Table" id="style-attribute-fontStyle-example-1-images" 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/></div><div class="div3">
-<h4><a name="style-attribute-fontWeight" id="style-attribute-fontWeight"/>8.2.11 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><table summary="HTML Table" id="style-property-details-fontWeight" class="common"><col width="25%" 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-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 specified font weight is not available, then a
-presentation processor must attempt to map the specified font weight
-to an available font weight that has similar typographic
-characteristics, or, in the absence of such a mapping, it must
-interpret the font weight as if the value <code>normal</code> were
-specified.</p><p>The <code>tts:fontWeight</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-fontWeight-example-1" 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/><table summary="HTML Table" id="style-attribute-fontWeight-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-lineHeight" id="style-attribute-lineHeight"/>8.2.12 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><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><table summary="HTML Table" id="style-property-details-lineHeight" class="common"><col width="25%" 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</td></tr></tbody></table><p>If the value of this attribute is <code>normal</code>, then the
-initial value of the style property must be considered to be the same
-as the largest font size that applies to any
-descendant element.</p><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 specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>normal</code> were specified.</p><p>The <code>tts:lineHeight</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-lineHeight-example-1" 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/><table summary="HTML Table" id="style-attribute-lineHeight-example-1-images" 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/></div><div class="div3">
-<h4><a name="style-attribute-opacity" id="style-attribute-opacity"/>8.2.13 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.</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.</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><table summary="HTML Table" id="style-property-details-opacity" class="common"><col width="25%" 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="#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>An <a href="#style-value-alpha">&lt;alpha&gt;</a> value greater
-than 1.0 must be considered equivalent to an <a href="#style-value-alpha">&lt;alpha&gt;</a> value of 1.0.</p><p>The <code>tts:opacity</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-opacity-example-1" 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/><table summary="HTML Table" id="style-attribute-opacity-example-1-images" 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><div class="div3">
-<h4><a name="style-attribute-origin" id="style-attribute-origin"/>8.2.14 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 root container extent,
-if specified, or the external authoring context, if not specified.</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><table summary="HTML Table" id="style-property-details-origin" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#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 root container region</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute consists of two <a href="#style-value-length">&lt;length&gt;</a> specifications,
-then they must be interpreted as <em>x</em> and <em>y</em> coordinates, where the first specification
-is the <em>x</em> coordinate, and the second specification is the <em>y</em> coordinate.</p><p>If the value of this attribute is <code>auto</code>, then the initial value
-of the style property must be considered to be the same as the root container
-origin.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>auto</code> were specified.</p><p>The <code>tts:origin</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-origin-example-1" class="example"><caption>Example Fragment – Origin</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style <span class="strong">tts:origin="40px 40px"</span>/&gt;
-  &lt;style tts:extent="308px 92px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="center"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  "To dine!" she shrieked in dragon-wrath.&lt;br/&gt;
-  "To swallow wines all foam and froth!&lt;br/&gt;
-   To simper at a table-cloth!"
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-origin-example-1-images" class="example-images"><caption>Example Rendition – Origin</caption><tbody><tr><td><img src="images/origin.png" alt="TTML origin style property"/></td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-overflow" id="style-attribute-overflow"/>8.2.15 tts:overflow</h4><p>The <code>tts:overflow</code> attribute is used to specify a style property that
-defines whether a region area is clipped or not if the descendant areas of the region overflow
-its extent.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-overflow" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>visible</code> |
-<code>hidden</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>hidden</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute is <code>visible</code>, then content should
-not be clipped outside of the affected region, and region composition and layout
-must be performed as if the region's width and height were
-unconstrained,
-but with
-a well-defined origin.  If the value is <code>hidden</code>, then content should
-be clipped outside of the affected region.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>Unless a manual line break element <code>br</code> is used by the content author,
-a paragraph of a given region will generate no more than one line area in that
-region if the value of the <code>tts:overflow</code> style that applies to the
-region is <code>visible</code> and if the applicable <code>tts:wrapOption</code>
-style is <code>noWrap</code>.</p></div><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>hidden</code> were specified.</p><p>The <code>tts:overflow</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-overflow-example-1" class="example"><caption>Example Fragment – Overflow</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="232px 40px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="red"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="18px"/&gt;
-  &lt;style tts:wrapOption="noWrap"/&gt;
-  &lt;style <span class="strong">tts:overflow="visible"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="232px 40px"/&gt;
-  &lt;style tts:origin="0px 43px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="red"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="18px"/&gt;
-  &lt;style tts:wrapOption="noWrap"/&gt;
-  &lt;style <span class="strong">tts:overflow="hidden"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  "But wait a bit," the Oysters cried,&lt;br/&gt;
-  "Before we have our chat;
-&lt;/p&gt;
-&lt;p region="r2"&gt;
-  For some of us are out of breath,&lt;br/&gt;
-  And all of us are fat!"
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-overflow-example-1-images" class="example-images"><caption>Example Rendition – Overflow</caption><tbody><tr><td><img src="images/overflow.png" alt="TTML overflow style property"/></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the <code>tts:noWrap</code> is set to
-<code>noWrap</code> to prevent automatic line wrapping (breaking);
-if this were not specified, then overflow would occur in the block
-progression direction as opposed to the inline progression direction.</p></div></div><div class="div3">
-<h4><a name="style-attribute-padding" id="style-attribute-padding"/>8.2.16 tts:padding</h4><p>The <code>tts:padding</code> attribute is used to specify padding (or inset)
-space on all sides of a region area.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-padding" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<a href="#style-value-length">&lt;length&gt;</a> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> |
-<a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a> <a href="#style-value-length">&lt;length&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>0px</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#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 region</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute consists of one <a href="#style-value-length">&lt;length&gt;</a> specification,
-then that length applies to all edges of the affected areas. If the value
-consists of two <a href="#style-value-length">&lt;length&gt;</a> specifications, then the first applies to the
-before and after edges, and the second applies to the start and end edges.
-If three <a href="#style-value-length">&lt;length&gt;</a> specifications are provided, then the first applies to the
-before edge, the second applies to the start and end edges, and the third applies
-to the after edge.
-If four <a href="#style-value-length">&lt;length&gt;</a> specifications are provided, then they apply to before, end,
-after, and start edges, respectively.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>0px</code> were specified.</p><p>The <code>tts:padding</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-padding-example-1" class="example"><caption>Example Fragment – Padding</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="446px 104px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-  &lt;style <span class="strong">tts:padding="10px 40px"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1" tts:backgroundColor="red"&gt;
-  Just the place for a Snark! I have said it twice:&lt;br/&gt;
-  That alone should encourage the crew.&lt;br/&gt;
-  Just the place for a Snark! I have said it thrice:&lt;br/&gt;
-  What I tell you three times is true.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p>When rendering an area to which padding applies, the background color that
-applies to the area is rendered into the padded portion of the area.</p><table summary="HTML Table" id="style-attribute-padding-example-1-images" class="example-images"><caption>Example Rendition – Padding</caption><tbody><tr><td>
-<img src="images/padding.png" alt="TTML padding style property"/>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-showBackground" id="style-attribute-showBackground"/>8.2.17 tts:showBackground</h4><p>The <code>tts:showBackground</code> attribute is used to specify
-constraints on when the background color of a region is intended to be
-presented.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-showBackground" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>always</code> |
-<code>whenActive</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>always</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If the value of this attribute is <code>always</code>, then the
-background color of a region is always rendered when performing presentation
-processing on a visual medium; if the value is <code>whenActive</code>,
-then the background color of a region is rendered only when some
-content is selected into the region.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>always</code> were specified.</p><p>The <code>tts:showBackground</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-showBackground-example-1" class="example"><caption>Example Fragment – Show Background</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:extent="265px 100px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style <span class="strong">tts:showBackground="always"</span>/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="start"/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:origin="205px 60px"/&gt;
-  &lt;style tts:extent="290px 100px"/&gt;
-  &lt;style tts:backgroundColor="red"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="before"/&gt;
-  &lt;style tts:textAlign="end"/&gt;
-  &lt;style <span class="strong">tts:showBackground="whenActive"</span>/&gt;
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-textAlign" id="style-attribute-textAlign"/>8.2.18 tts:textAlign</h4><p>The <code>tts:textAlign</code> attribute is used to specify a style property that
-defines how inline areas are aligned within a containing block area in the inline progression
-direction.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-textAlign" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>left</code> |
-<code>center</code> |
-<code>right</code> |
-<code>start</code> |
-<code>end</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>start</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>
-</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>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>start</code> were specified.</p><p>The <code>tts:textAlign</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-textAlign-example-1" class="example"><caption>Example Fragment – Text Align</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="355px 43px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:textAlign="start"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="355px 43px"/&gt;
-  &lt;style tts:origin="0px 47px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:textAlign="end"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  Beware the Jabberwock, my son!&lt;br/&gt;
-  The jaws that bite, the claws that catch!
-&lt;/p&gt;
-&lt;p region="r2"&gt;
-  Beware the Jubjub bird, and shun&lt;br/&gt;
-  The frumious Bandersnatch!
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-textAlign-example-1-images" class="example-images"><caption>Example Rendition – Text Align</caption><tbody><tr><td><img src="images/textAlign.png" alt="TTML textAlign style property"/></td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-textDecoration" id="style-attribute-textDecoration"/>8.2.19 tts:textDecoration</h4><p>The <code>tts:textDecoration</code> attribute is used to specify a style property that
-defines a text decoration effect to apply to glyph areas or other inline
-areas that are generated by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-textDecoration" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-[ [
-<code>underline</code> |
-<code>noUnderline</code>
-] || [
-<code>lineThrough</code> |
-<code>noLineThrough</code>
-] || [
-<code>overline</code> |
-<code>noOverline</code>
-] ]
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td><a href="#content-vocabulary-span"><code>span</code></a></td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this
-style property, each character child of a <code>p</code> element is
-considered to be enclosed in an anonymous span.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>none</code> were specified.</p><p>The <code>tts:textDecoration</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-textDecoration-example-1" class="example"><caption>Example Fragment – Text Decoration</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="385px 82px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:padding="5px 2px"/&gt;
-  &lt;style <span class="strong">tts:textDecoration="underline"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  The sea was wet&lt;span <span class="strong">tts:textDecoration="noUnderline"</span>&gt; as &lt;/span&gt;wet
-  &lt;span <span class="strong">tts:textDecoration="noUnderline"</span>&gt;
-    could be,&lt;br/&gt;
-    The sand was dry as dry.&lt;br/&gt;
-    &lt;span <span class="strong">tts:textDecoration="lineThrough"</span>&gt;There weren't any&lt;/span&gt;
-    You &lt;span <span class="strong">tts:textDecoration="lineThrough"</span>&gt;couldn't&lt;/span&gt;
-    could not see a cloud&lt;br/&gt;
-    Because no cloud was in the sky.
-  &lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-textDecoration-example-1-images" class="example-images"><caption>Example Rendition – Text Decoration</caption><tbody><tr><td><img src="images/textDecoration.png" alt="TTML textDecoration style property"/></td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-textOutline" id="style-attribute-textOutline"/>8.2.20 tts:textOutline</h4><p>The <code>tts:textOutline</code> attribute is used to specify a style property that
-defines a text outline effect to apply to glyphs that are selected for glyph areas generated
-by content flowed into a region.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-textOutline" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>none</code> |
-<a href="#style-value-color">&lt;color&gt;</a>?
-<a href="#style-value-length">&lt;length&gt;</a>
-<a href="#style-value-length">&lt;length&gt;</a>?
-</td></tr><tr><td><em>Initial:</em></td><td><code>none</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>relative to this element's font size</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The value of this attribute consists of an optional <a href="#style-value-color">&lt;color&gt;</a> term
-followed by one or two <a href="#style-value-length">&lt;length&gt;</a> terms.  If a <em>color</em> term is
-present, then it denotes the outline color; if no <em>color</em> term is
-present, the computed value of the <code>tts:color</code> applies.  The first
-<em>length</em> term denotes the outline thickness and the second length
-term, if present, indicates the blur radius.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>none</code> were specified.</p><p>The <code>tts:textOutline</code> style is illustrated by the following
-example.</p><table summary="HTML Table" id="style-attribute-textOutline-example-1" class="example"><caption>Example Fragment – Text Outline</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:backgroundColor="transparent"/&gt;
-  &lt;style tts:color="yellow"/&gt;
-  &lt;style <span class="strong">tts:textOutline="black 2px 0px"</span>/&gt;
-  &lt;style tts:fontFamily="proportionalSansSerif"/&gt;
-  &lt;style tts:fontSize="24px"/&gt;
-&lt;/region&gt;
-...
-&lt;p&gt;
-  How doth the little crocodile&lt;br/&gt;
-  Improve its shining tail,&lt;br/&gt;
-  And pour the waters of the Nile&lt;br/&gt;
-  On every golden scale!&lt;br/&gt;
-  How cheerfully he seems to grin,&lt;br/&gt;
-  How neatly spreads his claws,&lt;br/&gt;
-  And welcomes little fishes in,&lt;br/&gt;
-  With gently smiling jaws!
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-textOutline-example-1-images" class="example-images"><caption>Example Rendition – Text Outline</caption><tbody><tr><td><img src="images/textOutline.png" alt="backgroundColor style property"/></td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-unicodeBidi" id="style-attribute-unicodeBidi"/>8.2.21 tts:unicodeBidi</h4><p>The <code>tts:unicodeBidi</code> attribute is used to specify a style property that
-defines a directional embedding or override according to
-the Unicode bidirectional algorithm.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-unicodeBidi" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>normal</code> |
-<code>embed</code> |
-<code>bidiOverride</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>normal</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>normal</code> were specified.</p><p>The <code>tts:unicodeBidi</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-unicodeBidi-example-1" class="example"><caption>Example Fragment – Unicode Bidirectionality</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="265px 84px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:textAlign="center"/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  Little birds are playing&lt;br/&gt;
-  Bagpipes on the shore,&lt;br/&gt;
-  &lt;span <span class="strong">tts:unicodeBidi="bidiOverride"</span> tts:direction="rtl"&gt;where the tourists snore.&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-unicodeBidi-example-1-images" class="example-images"><caption>Example Rendition – Unicode Bidirectionality</caption><tbody><tr><td>
-<img src="images/unicodeBidi.png" alt="TTML unicodeBidi style property"/>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-visibility" id="style-attribute-visibility"/>8.2.22 tts:visibility</h4><p>The <code>tts:visibility</code> attribute is used to specify a style property that
-defines whether generated areas are visible or not when rendered on a visual
-presentation medium.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-visibility" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>visible</code> |
-<code>hidden</code>
-</td></tr><tr><td><em>Initial:</em></td><td>
-<code>visible</code>
-</td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#layout-vocabulary-region"><code>region</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>The <code>tts:visibility</code> style has no affect on content layout or
-composition, but merely determines whether composed content is visible or not.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>visible</code> were specified.</p><p>The <code>tts:visibility</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-visibility-example-1" class="example"><caption>Example Fragment – Visibility</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="398px 121px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1" dur="4s"&gt;
-  &lt;span <span class="strong">tts:visibility="hidden"</span>&gt;
-    &lt;set begin="1s" <span class="strong">tts:visibility="visible"</span>/&gt;
-    Curiouser
-  &lt;/span&gt;
-  &lt;span <span class="strong">tts:visibility="hidden"</span>&gt;
-    &lt;set begin="2s" <span class="strong">tts:visibility="visible"</span>/&gt;
-    and
-  &lt;/span&gt;
-  &lt;span <span class="strong">tts:visibility="hidden"</span>&gt;
-    &lt;set begin="3s" <span class="strong">tts:visibility="visible"</span>/&gt;
-    curiouser!
-  &lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-visibility-example-1-images" class="example-images"><caption>Example Rendition – Visibility</caption><tbody><tr><td>
-<img src="images/visibility_0.png" alt="TTML visibility style property - [0,1)"/>
-</td></tr><tr><td>
-<img src="images/visibility_1.png" alt="TTML visibility style property - [1,2)"/>
-</td></tr><tr><td>
-<img src="images/visibility_2.png" alt="TTML visibility style property - [2,3)"/>
-</td></tr><tr><td>
-<img src="images/visibility_3.png" alt="TTML visibility style property - [3,4)"/>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-wrapOption" id="style-attribute-wrapOption"/>8.2.23 tts:wrapOption</h4><p>The <code>tts:wrapOption</code> attribute is used to specify a style property that
-defines whether or not automatic line wrapping (breaking) applies within the context of
-the affected element.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-wrapOption" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>wrap</code> |
-<code>noWrap</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>wrap</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#content-vocabulary-span"><code>span</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>yes</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>For the purpose of determining applicability of this style property,
-each character child of a <code>p</code> element is considered to be enclosed in an anonymous
-span.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>wrap</code> were specified.</p><p>The <code>tts:wrapOption</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-wrapOption-example-1" class="example"><caption>Example Fragment – Wrap Option</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="192px 117px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:displayAlign="after"/&gt;
-  &lt;style tts:overflow="hidden"/&gt;
-  &lt;style <span class="strong">tts:wrapOption="noWrap"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p&gt;
-  I'll tell thee everything I can:&lt;br/&gt;
-  There's little to relate.&lt;br/&gt;
-  I saw an aged aged man,&lt;br/&gt;
-  A-sitting on a gate.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-wrapOption-example-1-images" class="example-images"><caption>Example Rendition – Wrap Option</caption><tbody><tr><td><img src="images/wrapOption.png" alt="TTML wrapOption style property"/></td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-attribute-writingMode" id="style-attribute-writingMode"/>8.2.24 tts:writingMode</h4><p>The <code>tts:writingMode</code> attribute is used to specify a style property that
-defines the block and inline progression directions to be used for the purpose of
-stacking block and inline areas within a region area.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-writingMode" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>lrtb</code> |
-<code>rltb</code> |
-<code>tbrl</code> |
-<code>tblr</code> |
-<code>lr</code> |
-<code>rl</code> |
-<code>tb</code>
-</td></tr><tr><td><em>Initial:</em></td><td><code>lrtb</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>lrtb</code> were specified.</p><p>The <code>tts:writingMode</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-writingMode-example-1" class="example"><caption>Example Fragment – Writing Mode</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:extent="50px 570px"/&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:padding="10px 3px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:writingMode="tbrl"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:extent="310px 50px"/&gt;
-  &lt;style tts:origin="70px 120px"/&gt;
-  &lt;style tts:padding="10px 3px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:writingMode="rltb"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  I sometimes dig for buttered rolls,&lt;br/&gt;
-  Or set limed twigs for crabs:
-&lt;/p&gt;
-&lt;p region="r2" tts:direction="rtl" tts:unicodeBidi="bidiOverride"&gt;
-  I sometimes search the grassy knolls for the wheels of Hansom-cabs.
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><table summary="HTML Table" id="style-attribute-writingMode-example-1-images" class="example-images"><caption>Example Rendition – Writing Mode</caption><tbody><tr><td><img src="images/writingMode.png" alt="TTML writingMode style property"/></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the second paragraph in the above example that targets region
-<code>r2</code>, the <code>tts:unicodeBidi</code> and
-<code>tts:direction</code> properties are set to
-<code>bidiOverride</code> and <code>rtl</code>, respectively, in order
-to override the normally left-to-right directionality of characters in
-the Latin script.</p></div></div><div class="div3">
-<h4><a name="style-attribute-zIndex" id="style-attribute-zIndex"/>8.2.25 tts:zIndex</h4><p>The <code>tts:zIndex</code> attribute is used to specify a style property that
-defines the front-to-back ordering of region areas in the case that they overlap.</p><p>This attribute may be specified by any
-element type
-that permits use of attributes in the TT Style Namespace; however, this attribute applies
-as a style property only to those element types indicated in the following table.</p><table summary="HTML Table" id="style-property-details-zIndex" class="common"><col width="25%" span="1"/><tbody><tr><td><em>Values:</em></td><td>
-<code>auto</code> |
-<a href="#style-value-integer">&lt;integer&gt;</a>
-</td></tr><tr><td><em>Initial:</em></td><td><code>auto</code></td></tr><tr><td><em>Applies to:</em></td><td>
-<a href="#layout-vocabulary-region"><code>region</code></a>
-</td></tr><tr><td><em>Inherited:</em></td><td>no</td></tr><tr><td><em>Percentages:</em></td><td>N/A</td></tr><tr><td><em>Animatable:</em></td><td>discrete</td></tr></tbody></table><p>If two areas are associated with the same Z-index value, then, if those areas
-overlap in space, the area(s) generated by lexically subsequent elements must be
-rendered over area(s) generated by lexically prior elements, where lexical
-order is defined as the postorder traversal of a document
-instance.</p><p>The semantics of the value <code>auto</code> are those defined by
-<a href="#xsl11">[XSL 1.1]</a>, § 7.30.18, where the <code>tt</code> element
-is considered to establish the root stacking context.</p><p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>auto</code> were specified.</p><p>The <code>tts:zIndex</code> style is illustrated by the following example.</p><table summary="HTML Table" id="style-attribute-zIndex-example-1" class="example"><caption>Example Fragment – Z Index</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  &lt;style tts:origin="0px 0px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:zIndex="0"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r2"&gt;
-  &lt;style tts:origin="100px 60px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="red"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:textAlign="end"/&gt;
-  &lt;style <span class="strong">tts:zIndex="1"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r3"&gt;
-  &lt;style tts:origin="0px 120px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="black"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style <span class="strong">tts:zIndex="2"</span>/&gt;
-&lt;/region&gt;
-&lt;region xml:id="r4"&gt;
-  &lt;style tts:origin="100px 180px"/&gt;
-  &lt;style tts:extent="400px 100px"/&gt;
-  &lt;style tts:padding="5px"/&gt;
-  &lt;style tts:backgroundColor="red"/&gt;
-  &lt;style tts:color="white"/&gt;
-  &lt;style tts:textAlign="end"/&gt;
-  &lt;style <span class="strong">tts:zIndex="3"</span>/&gt;
-&lt;/region&gt;
-...
-&lt;p region="r1"&gt;
-  I passed by his garden, and marked, with one eye,&lt;br/&gt;
-  How the Owl and the Panther were sharing a pie.
-&lt;/p&gt;
-&lt;p region="r2"&gt;
-  The Panther took pie-crust, and gravy, and meat,&lt;br/&gt;
-  While the Owl had the dish as its share of the treat.
-&lt;/p&gt;
-&lt;p region="r3"&gt;
-  When the pie was all finished, the Owl, as a boon,&lt;br/&gt;
-  Was kindly permitted to pocket the spoon:
-&lt;/p&gt;
-&lt;p region="r4"&gt;
-  While the Panther received knife and fork&lt;br/&gt;
-  with a growl,&lt;br/&gt;
-  And concluded the banquet by...
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><p/><p/><table summary="HTML Table" id="style-attribute-zIndex-example-1-images" class="example-images"><caption>Example Rendition – Z Index</caption><tbody><tr><td><img src="images/zIndex.png" alt="TTML zIndex style property"/></td></tr></tbody></table></div></div><div class="div2">
-<h3><a name="styling-style-value-expressions" id="styling-style-value-expressions"/>8.3 Style Value Expressions</h3><p>Style property values include the use of the following expressions:</p><ul><li><p><a href="#style-value-alpha"><b>8.3.1 &lt;alpha&gt;</b></a></p></li><li><p><a href="#style-value-color"><b>8.3.2 &lt;color&gt;</b></a></p></li><li><p><a href="#style-value-digit"><b>8.3.3 &lt;digit&gt;</b></a></p></li><li><p><a href="#style-value-duration"><b>8.3.4 &lt;duration&gt;</b></a></p></li><li><p><a href="#style-value-familyName"><b>8.3.5 &lt;familyName&gt;</b></a></p></li><li><p><a href="#style-value-genericFamilyName"><b>8.3.6 &lt;genericFamilyName&gt;</b></a></p></li><li><p><a href="#style-value-hexDigit"><b>8.3.7 &lt;hexDigit&gt;</b></a></p></li><li><p><a href="#style-value-integer"><b>8.3.8 &lt;integer&gt;</b></a></p></li><li><p><a href="#style-value-length"><b>8.3.9 &lt;length&gt;</b></a></p></li><li><p><a href="#style-value-namedColor"><b>8.3.10 &lt;namedColor&gt;</b></a></p></li><li><p><a href="#style-value-quotedString"><b>8.3.11 &lt;quotedString&gt;</b></a></p></li><li><p><a href="#style-value-string"><b>8.3.12 &lt;string&gt;</b></a></p></li></ul><div class="div3">
-<h4><a name="style-value-alpha" id="style-value-alpha"/>8.3.1 &lt;alpha&gt;</h4><p>An &lt;alpha&gt; expression is used to express an opacity value,
-where	0 means fully transparent and 1 means fully opaque.</p><table summary="HTML Table" id="alpha-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;alpha&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;alpha&gt;
-  : <em>float</em>
-</pre></div>
-</td></tr></tbody></table><p>In the above syntax representation, the syntactic element
-<em><code>float</code></em> must adhere to the lexical
-representation defined by <a href="#xsd-2">[XML Schema Part 2]</a> §
-3.2.4.1. If the value represented is less than 0.0,
-then it must be interpreted as equal to 0.0; similarly, if the value
-represented is greater than 1.0, then it must be interpreted as
-1.0. The value NaN shall be interpreted as 0.0.</p><p>If a presentation processor does not support a specific,
-valid opacity value, then it must interpret it as being equal to the
-closest supported value.</p></div><div class="div3">
-<h4><a name="style-value-color" id="style-value-color"/>8.3.2 &lt;color&gt;</h4><p>A &lt;color&gt; expression is used to specify a named color, exact RGB color triple,
-or exact RGBA color tuple, where the alpha component, if expressed,
-is maximum (255) at 100% opacity
-and minimum (0) at 0% opacity, and where the applicable color space is
-defined by <a href="#srgb">[SRGB]</a>.</p><table summary="HTML Table" id="color-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;color&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;color&gt;
-  : "#" rrggbb
-  | "#" rrggbbaa
-  | "rgb" "(" r-value "," g-value "," b-value ")"
-  | "rgba" "(" r-value "," g-value "," b-value "," a-value ")"
-  | <a href="#style-value-namedColor">&lt;namedColor&gt;</a>
-
-rrggbb
-  :  <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a>{6}
-
-rrggbbaa
-  :  <a href="#style-value-hexDigit">&lt;hexDigit&gt;</a>{8}
-
-r-value | g-value | b-value | a-value
-  : component-value
-
-component-value
-  : non-negative-integer                    // valid range: [0,255]
-
-non-negative-integer
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table><p>When expressing RGB component values, these values are considered
-to <span class="strong">not</span> be premultiplied by alpha.</p><p>For the purpose of performing presentation processing such that
-non-opaque or non-transparent alpha or opacity values apply, then the
-semantics of compositing functions are defined with respect to the use of
-the <a href="#srgb">[SRGB]</a> color space for both inputs and outputs of
-the composition function.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of <a href="#srgb">[SRGB]</a> for the stated semantics of
-composition is not meant to prevent an actual processor from using some
-other color space either for internal or external purposes. For
-example, a presentation processor may ultimately convert the SRGB values
-used here to the YUV color space for rendition on a television device.</p></div><p>If a presentation processor does not support a specific,
-valid color or alpha value, then it must interpret it as being equal
-to the closest supported value.</p></div><div class="div3">
-<h4><a name="style-value-digit" id="style-value-digit"/>8.3.3 &lt;digit&gt;</h4><p>A &lt;digit&gt; is used to express integers and other types of numbers or tokens.</p><table summary="HTML Table" id="digit-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;digit&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;digit&gt;
-  : "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-value-duration" id="style-value-duration"/>8.3.4 &lt;duration&gt;</h4><p>A &lt;duration&gt; expression is used to express a temporal duration value.</p><table summary="HTML Table" id="duration-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;duration&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;duration&gt;
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+ ( "." <a href="#style-value-digit">&lt;digit&gt;</a>+ )? metric
-
-metric
-  : "s"                 // seconds
-  | "ms"                // milliseconds
-  | "f"                 // frames
-  | "t"                 // ticks
-</pre></div>
-</td></tr></tbody></table><p>It is an error to omit the metric component of a duration.</p><p>When operating with <code>smpte</code> time base and
-<code>discontinuous</code> mode, a duration expression must be
-considered to denote a duration in (local) real-time, independently of the
-governing time base.</p></div><div class="div3">
-<h4><a name="style-value-familyName" id="style-value-familyName"/>8.3.5 &lt;familyName&gt;</h4><p>A &lt;familyName&gt; expression specifies a font family name.</p><p>If the name contains a quotation delimiter character,
-then it must be expressed as a
-&lt;quotedString&gt;. If the name contains a
-whitespace character,
-then it should be expressed as a
-&lt;quotedString&gt;; however, if it is expressed as a &lt;string&gt;, then it
-must not contain a <code>COMMA</code> ',' character.</p><table summary="HTML Table" id="familyName-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;familyName&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;familyName&gt;
-  : <a href="#style-value-string">&lt;string&gt;</a>
-  | <a href="#style-value-quotedString">&lt;quotedString&gt;</a>
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-value-genericFamilyName" id="style-value-genericFamilyName"/>8.3.6 &lt;genericFamilyName&gt;</h4><p>A &lt;genericFamilyName&gt; expression specifies a font family using a general
-token that indicates a class of font families.</p><p>The resolution of a generic family name to a concrete font instance is considered to
-be implementation dependent, both in the case of content authoring and content interpretation.</p><table summary="HTML Table" id="genericFamilyName-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;genericFamilyName&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;genericFamilyName&gt;
-  : "default"
-  | "monospace"
-  | "sansSerif"
-  | "serif"
-  | "monospaceSansSerif"
-  | "monospaceSerif"
-  | "proportionalSansSerif"
-  | "proportionalSerif"
-</pre></div>
-</td></tr></tbody></table><p>The mapping between a generic (font) family name and an actual font is not
-determined by this specification; however, the
-distinction of monospace versus proportional and serif versus sans-serif
-should be maintained if possible when performing presentation.</p><p>If a generic (font) family name of <code>monospace</code> is specified,
-then it may be interpreted as equivalent to either <code>monospaceSansSerif</code>
-or <code>monospaceSerif</code>. The generic family names <code>sansSerif</code>
-and <code>serif</code> are to be interpreted as equivalent to <code>proportionalSansSerif</code>
-and <code>proportionalSerif</code>, respectively.</p><p>If the generic family name <code>default</code> is specified (or implied by
-an initial value), then its typographic characteristics is considered to be implementation
-dependent; however, it is recommended that this default font family be mapped to
-an monospaced, sans-serif font.</p></div><div class="div3">
-<h4><a name="style-value-hexDigit" id="style-value-hexDigit"/>8.3.7 &lt;hexDigit&gt;</h4><p>A &lt;hexDigit&gt; is used to express integers and other types of numbers or tokens
-that employ base 16 arithmetic.</p><p>For the purpose of parsing, no distinction must be made between lower and upper case.</p><table summary="HTML Table" id="hexDigit-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;hexDigit&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;hexDigit&gt;
-  : <a href="#style-value-digit">&lt;digit&gt;</a>
-  | "a" | "b" | "c" | "d" | "e" | "f"
-  | "A" | "B" | "C" | "D" | "E" | "F"
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-value-integer" id="style-value-integer"/>8.3.8 &lt;integer&gt;</h4><p>An &lt;integer&gt; expression is used to express an arbitrary, signed integral value.</p><table summary="HTML Table" id="integer-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;integer&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;integer&gt;
-  : ( "+" | "-" )? <a href="#style-value-digit">&lt;digit&gt;</a>+
-</pre></div>
-</td></tr></tbody></table></div><div class="div3">
-<h4><a name="style-value-length" id="style-value-length"/>8.3.9 &lt;length&gt;</h4><p>A &lt;length&gt; expression is used to express either a coordinate component of point
-in a cartesian space or a distance between two points in a cartesian space.</p><table summary="HTML Table" id="length-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;length&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;length&gt;
-  : scalar
-  | percentage
-
-scalar
-  : number units
-
-percentage
-  : number "%"
-
-sign
-  : "+" | "-"
-
-number
-  : sign? non-negative-number
-
-non-negative-number
-  : non-negative-integer
-  | non-negative-real
-
-non-negative-integer
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-non-negative-real
-  : <a href="#style-value-digit">&lt;digit&gt;</a>* "." <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-units
-  : "px"
-  | "em"
-  | "c"                                     // abbreviation of "cell"
-</pre></div>
-</td></tr></tbody></table><p>It is an error to omit the units component of a scalar length
-value.</p><p>The semantics of
-the unit of measure <code>px</code> (pixel) 
-are as defined by <a href="#xsl11">[XSL 1.1]</a>, § 5.9.13.</p><p>When specified relative to a font whose size is expressed as a single length
-measure or as two length measures of equal length, the unit of measure <code>em</code> is considered to be
-identical to that defined by <a href="#xsl11">[XSL 1.1]</a>, § 5.9.13;
-however, when specified relative to a font whose size is expressed as
-two length measures of non-equal lengths, then one <code>em</code> is
-equal to the inline progression dimension of the anamorphically
-scaled font when used to specify lengths in the inline progression
-direction and equal to the block progression dimension of the scaled
-font when used to specify lengths in the block progression direction.</p><p>The semantics of the unit of measure <code>c</code> (cell) are
-defined by the parameter <a href="#parameter-attribute-cellResolution"><b>6.2.1 ttp:cellResolution</b></a>.</p></div><div class="div3">
-<h4><a name="style-value-namedColor" id="style-value-namedColor"/>8.3.10 &lt;namedColor&gt;</h4><p>A &lt;namedColor&gt; is used to express an RGBA color with a convenient name, and where the applicable color space is
-defined by <a href="#srgb">[SRGB]</a>.</p><p>For the purpose of parsing, no distinction must be made between lower and upper case.</p><table summary="HTML Table" id="namedColor-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;namedColor&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;namedColor&gt;
-  : "transparent"                           // #00000000
-  | "black"                                 // #000000ff
-  | "silver"                                // #c0c0c0ff
-  | "gray"                                  // #808080ff
-  | "white"                                 // #ffffffff
-  | "maroon"                                // #800000ff
-  | "red"                                   // #ff0000ff
-  | "purple"                                // #800080ff
-  | "fuchsia"                               // #ff00ffff
-  | "magenta"                               // #ff00ffff (= fuchsia)
-  | "green"                                 // #008000ff
-  | "lime"                                  // #00ff00ff
-  | "olive"                                 // #808000ff
-  | "yellow"                                // #ffff00ff
-  | "navy"                                  // #000080ff
-  | "blue"                                  // #0000ffff
-  | "teal"                                  // #008080ff
-  | "aqua"                                  // #00ffffff
-  | "cyan"                                  // #00ffffff (= aqua)
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>Except for <code>transparent</code>, the set of named colors specified above constitutes a proper
-subset of the set of named colors specified by <a href="#svg11">[SVG 1.1]</a>, § 4.2.</p></div></div><div class="div3">
-<h4><a name="style-value-quotedString" id="style-value-quotedString"/>8.3.11 &lt;quotedString&gt;</h4><p>A &lt;quotedString&gt; is used to express a delimited string that may contain
-a whitespace or a quotation delimiter character. Two types of quotation delimiters
-are provided in order to accommodate strings that contain the other delimiter.</p><table summary="HTML Table" id="quotedString-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;quotedString&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;quotedString&gt;
-  : "\"" ( <em>char</em> - { "\"" } )* "\""
-  | "\'" ( <em>char</em> - { "\'" } )* "\'"
-</pre></div>
-</td></tr></tbody></table><p>In the above syntax representation, the syntactic element <em><code>char</code></em> must adhere to production
-[2] <code>Char</code> as defined by <a href="#xml10">[XML 1.0]</a> §
-2.2.</p></div><div class="div3">
-<h4><a name="style-value-string" id="style-value-string"/>8.3.12 &lt;string&gt;</h4><p>A &lt;string&gt; expression consists of a sequence of characters where no character
-is a quotation delimiter character.</p><table summary="HTML Table" id="string-style-expression-syntax" class="syntax"><caption>Syntax Representation – &lt;string&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;string&gt;
-  : ( <em>char</em> - { "\"" | "\'" } )+
-</pre></div>
-</td></tr></tbody></table><p>In the above syntax representation, the syntactic element <em><code>char</code></em> must adhere to production
-[2] <code>Char</code> as defined by <a href="#xml10">[XML 1.0]</a> §
-2.2.</p></div></div><div class="div2">
-<h3><a name="semantics-style-resolution" id="semantics-style-resolution"/>8.4 Style Resolution</h3><p>This section defines the semantics of style resolution in terms of
-a standard processing model as follows:</p><ul><li><p><a href="#semantics-style-association"><b>8.4.1 Style Association</b></a></p></li><li><p><a href="#semantics-style-inheritance"><b>8.4.2 Style Inheritance</b></a></p></li><li><p><a href="#semantics-style-resolution-value-categories"><b>8.4.3 Style Resolution Value Categories</b></a></p></li><li><p><a href="#semantics-style-resolution-processing"><b>8.4.4 Style Resolution Processing</b></a></p></li></ul><p>Any implementation of this model is permitted provided that the
-externally observable results are consistent with the results produced
-by this model.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of style resolution employed here are based upon
-<a href="#xsl11">[XSL 1.1]</a>, § 5.</p></div><div class="div3">
-<h4><a name="semantics-style-association" id="semantics-style-association"/>8.4.1 Style Association</h4><p>Style association is a sub-process of <a href="#semantics-style-resolution-processing"><b>8.4.4 Style Resolution Processing</b></a> used to determine the
-specified style set of each content and
-layout element.</p><p>Style matter may be associated with content
- and layout matter in a number of ways:</p><ul><li><p><a href="#semantics-style-association-inline">inline styling</a></p></li><li><p><a href="#semantics-style-association-referential">referential styling</a></p></li><li><p><a href="#semantics-style-association-chained-referential">chained referential styling</a></p></li></ul><p>In addition to the above, style matter may be associated with layout matter using:</p><ul><li><p><a href="#semantics-style-association-nested">nested styling</a></p></li></ul><div class="div4">
-<h5><a name="semantics-style-association-inline" id="semantics-style-association-inline"/>8.4.1.1 Inline Styling</h5><p>Style properties may be expressed in an inline manner by direct
-specification of an attribute from the TT Style Namespace on the
-affected element. When expressed in this manner, the association of
-style information is referred to as <em>inline styling</em>.</p><p>Style properties associated by inline styling are afforded a higher priority than all other
-forms of style association.</p><table summary="HTML Table" id="style-association-example-1" class="example"><caption>Example – Inline Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;p <span class="strong">tts:color="white"</span>&gt;White 1 &lt;span <span class="strong">tts:color="yellow"</span>&gt;Yellow&lt;/span&gt; White 2&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the two text fragments <code>"White 1 "</code> and
-<code>" White 2"</code>, which are interpreted as anonymous spans, are not
-associated with a color style property; rather, they inherit their color style
-from their parent <code>p</code> element as described in <a href="#semantics-style-inheritance-content"><b>8.4.2.1 Content Style Inheritance</b></a> below.  </p></div></div><div class="div4">
-<h5><a name="semantics-style-association-referential" id="semantics-style-association-referential"/>8.4.1.2 Referential Styling</h5><p>Style properties may be expressed in an out-of-line manner and referenced by the
-affected element using the <code>style</code> attribute. When expressed in this manner,
-the association of style information is referred to as <em>referential styling</em>.</p><p>If a <code>style</code> attribute specifies multiple references, then those references are
-evaluated in the specified order, and that order applies to resolution of the value of a
-style property in the case that it is specified along multiple reference paths.</p><p>The use of referential styling is restricted to making
-reference to <code>style</code> element descendants of a <code>styling</code>
-element. It is considered an error to reference a <code>style</code>
-element that is a descendant of a <code>layout</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of referential styling encourages the reuse of style specifications while
-sacrificing locality of reference.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>A single content element may be associated with style properties by a hybrid mixture of
-inline and referential styling, in which case inline styling is given priority as described above
-by <a href="#semantics-style-association-inline"><b>8.4.1.1 Inline Styling</b></a>.</p></div><table summary="HTML Table" id="style-association-example-2" class="example"><caption>Example – Referential Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;style <span class="strong">xml:id="s1"</span> tts:color="white"/&gt;
-&lt;style <span class="strong">xml:id="s2"</span> tts:color="yellow"/&gt;
-...
-&lt;p <span class="strong">style="s1"</span>&gt;White 1 &lt;span <span class="strong">style="s2"</span>&gt;Yellow&lt;/span&gt; White 2&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the two text fragments <code>"White 1 "</code> and
-<code>" White 2"</code>, which are interpreted as anonymous spans, are not
-associated with a color style property; rather, they inherit their color style
-from their parent <code>p</code> element as described in <a href="#semantics-style-inheritance-content"><b>8.4.2.1 Content Style Inheritance</b></a> below.</p></div></div><div class="div4">
-<h5><a name="semantics-style-association-chained-referential" id="semantics-style-association-chained-referential"/>8.4.1.3 Chained Referential Styling</h5><p>Style properties may be expressed in an out-of-line manner and may themselves reference
-other out-of-line style properties, thus creating a chain of references starting at the
-affected element. When expressed in this manner, the association of style information
-is referred to as <em>chained referential styling</em>.</p><p>If the same style property is specified in more than one referenced
-style 
-set,
-then the last referenced style
-set
-applies, where the order of application starts from
-the affected element and proceeds to referenced style
-sets,
-and, in turn, to subsequent, recursively
-referenced style
-sets.</p><p>A loop in a sequence of chained style references must be considered an error.</p><p>The use of referential styling is restricted to making
-reference to <code>style</code> element descendants of a <code>styling</code>
-element. It is considered an error to reference a <code>style</code>
-element that is a descendant of a <code>layout</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of chained referential styling encourages the grouping of style specifications
-into general and specific sets, which further aids in style specification reuse.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>A single content element may be associated with style properties by a hybrid mixture of
-inline, referential styling, and chained referential styling, in which case inline styling is
-given priority as described above by <a href="#semantics-style-association-inline"><b>8.4.1.1 Inline Styling</b></a>.</p></div><table summary="HTML Table" id="style-association-example-3" class="example"><caption>Example – Chained Referential Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;style <span class="strong">xml:id="s1"</span> tts:color="white" tts:fontFamily="monospaceSerif"/&gt;
-&lt;style <span class="strong">xml:id="s2"</span> <span class="strong">style="s1"</span> tts:color="yellow"/&gt;
-...
-&lt;p <span class="strong">style="s1"</span>&gt;White Monospace&lt;/p&gt;
-&lt;p <span class="strong">style="s2"</span>&gt;Yellow Monospace&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table></div><div class="div4">
-<h5><a name="semantics-style-association-nested" id="semantics-style-association-nested"/>8.4.1.4 Nested Styling</h5><p>Style properties may be expressed in an nested manner by direct specification of one or
-more <code>style</code> element children of the affected element.
-When expressed in this manner, the association of style information
-is referred to as <em>nested styling</em>.</p><p>Style properties associated by nested styling are afforded a lower priority than inline
-styling but with higher priority than referential styling.</p><table summary="HTML Table" id="style-association-example-4" class="example"><caption>Example – Nested Styling</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region xml:id="r1"&gt;
-  <span class="strong">&lt;style tts:extent="128px 66px"/&gt;</span>
-  <span class="strong">&lt;style tts:origin="0px 0px"/&gt;</span>
-  <span class="strong">&lt;style tts:displayAlign="center"/&gt;</span>
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In this version of this specification, nested styling applies only
-to the <code>region</code> element.</p></div></div></div><div class="div3">
-<h4><a name="semantics-style-inheritance" id="semantics-style-inheritance"/>8.4.2 Style Inheritance</h4><p>Style inheritance is a sub-process of <a href="#semantics-style-resolution-processing"><b>8.4.4 Style Resolution Processing</b></a> used to determine the
-specified style set of each content and
-layout element.</p><p>Styles are further propagated to content matter
-using:
-</p><ul><li><p><a href="#semantics-style-inheritance-content">content style inheritance</a></p></li><li><p><a href="#semantics-style-inheritance-content">region style inheritance</a></p></li></ul><p>For the purpose of determining inherited styles, the element hierarchy of
-an intermediate synchronic document form of a TTML document instance must be used, where
-such intermediate forms are defined by <a href="#semantics-region-layout-step-1"><b>9.3.2 Intermediate Synchronic Document Construction</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The intermediate synchronic document form is utilized rather than
-the original form in order to facilitate region inheritance
-processing.</p></div><div class="div4">
-<h5><a name="semantics-style-inheritance-content" id="semantics-style-inheritance-content"/>8.4.2.1 Content Style Inheritance</h5><p>Style properties are inherited from ancestor content elements
-within an intermediate synchronic document
-if a style property is not associated with a content element (or
-an anonymous span) and the style property is designated as
-inheritable.</p><p>If a style property is determined to require inheritance, then the inherited value must
-be the value of the same named style property in the computed
-style set of the
-element's immediate ancestor element
-within the applicable intermediate synchronic document.</p><table summary="HTML Table" id="style-inheritance-example-2" class="example"><caption>Example – Content Style Inheritance</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;p <span class="strong">tts:fontFamily="monospaceSansSerif"</span>&gt;
-  &lt;span tts:color="yellow"&gt;Yellow Monospace&lt;/span&gt;
-&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the <code>span</code> element that encloses the character items
-<code>Yellow Monospace</code> is not associated with a <code>tts:fontFamily</code> style
-property and this property is inheritable; therefore, the value of the
-<code>tts:fontFamily</code> style
-is inherited from the computed style
-set of the ancestor <code>p</code> element,
-and is added to the
-specified
-style
-set of the <code>span</code> element.</p></div></div><div class="div4">
-<h5><a name="semantics-style-inheritance-region" id="semantics-style-inheritance-region"/>8.4.2.2 Region Style Inheritance</h5><p>Style properties are inherited from a region element in the following case:</p><ol class="enumar"><li><p>if a style property <em>P</em> is not associated with
-a content
-element or an anonymous span <em>E</em> and the style
-property is designated as inheritable, and</p></li><li><p>if that
-style property <em>P</em> is in the computed style
-set of region
-<em>R</em>,
-and</p></li><li><p>if that element <em>E</em> is flowed into (presented within) region
-<em>R</em>.</p></li></ol><table summary="HTML Table" id="style-inheritance-example-3" class="example"><caption>Example – Region Style Inheritance</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;region <span class="strong">xml:id="r1"</span>&gt;
-  &lt;style tts:color="yellow"/&gt;
-  &lt;style tts:fontFamily="monospaceSerif"/&gt;
-&lt;/region&gt;
-...
-&lt;p <span class="strong">region="r1"</span>&gt;Yellow Monospace&lt;/p&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the anonymous span that encloses the character
-items <code>Yellow Monospace</code> effectively inherits the <code>tts:color</code>
-and <code>tts:fontFamily</code> styles specified on the <code>region</code>
-element into which the <code>p</code> element is flowed (presented).</p></div></div></div><div class="div3">
-<h4><a name="semantics-style-resolution-value-categories" id="semantics-style-resolution-value-categories"/>8.4.3 Style Resolution Value Categories</h4><p>During style resolution, layout, and presentation processing,
-three categories of style property values are distinguished as
-follows:</p><ul><li><p><a href="#semantics-style-resolved-value-category-specified">specified values</a></p></li><li><p><a href="#semantics-style-resolved-value-category-computed">computed values</a></p></li><li><p><a href="#semantics-style-resolved-value-category-actual">actual values</a></p></li></ul><div class="div4">
-<h5><a name="semantics-style-resolved-value-category-specified" id="semantics-style-resolved-value-category-specified"/>8.4.3.1 Specified Values</h5><p>Values of style properties that are associated with or inherited
-by an element or anonymous span are referred to as <em>specified values</em>. The
-set of all specified style properties of a given element is referred to
-as the <em>specified style set</em> of that element.</p></div><div class="div4">
-<h5><a name="semantics-style-resolved-value-category-computed" id="semantics-style-resolved-value-category-computed"/>8.4.3.2 Computed Values</h5><p>When style properties are specified using relative value expressions,
-such as a named color, a relative unit (e.g., cell), or a percentage, then
-they need to be further resolved into absolute units, such as an RGB triple,
-pixels, etc.</p><p>During the style resolution process, all specified style values are
-reinterpreted (or recalculated) in absolute terms, and then recorded as
-<em>computed values</em>. The
-set of all computed style properties of a given element is referred to
-as the <em>computed style set</em> of that element.</p><p>When a style value is inherited, either explicitly or implicitly, it
-is the computed value of the style that is inherited from an ancestor
-element. This is required since the resolution of certain relative units,
-such as percentage, require evaluating the expression in the immediate
-(local) context of reference, and not in a distant (remote) context of
-reference where the related (resolving) expression is not available.</p></div><div class="div4">
-<h5><a name="semantics-style-resolved-value-category-actual" id="semantics-style-resolved-value-category-actual"/>8.4.3.3 Actual Values</h5><p>During the actual presentation process, other transformations occur
-that map some value expressions to concrete, physical values. For example,
-the colors of computed style values are further subjected to closest color
-approximation and gamma correction
-during the display process. In addition, length value expressions that use
-pixels in computed style values are considered to express logical rather than
-physical (device) pixels. Consequently, these logical pixels are subject to
-being further transformed or mapped to physical (device) pixels during
-presentation.</p><p>The final values that result from the logical to device mapping
-process are referred to as <em>actual values</em>.  The set of all
-actual style properties of a given element is referred to as the
-<em>actual style set</em> of that element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>More than one set of actual values may be produced during the
-process of presentation. For example, a TTML presentation processor
-device may output an RGBA component video signal which is then
-further transformed by an NTSC or PAL television to produce a final
-image. In this case, both color and dimensions may further be modified
-prior to presentation.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>In general, a TTML presentation processor will not have access
-to actual style set values; as a consequence, no further use or reference
-to actual values is made below when formally describing the style
-resolution process.</p></div></div></div><div class="div3">
-<h4><a name="semantics-style-resolution-processing" id="semantics-style-resolution-processing"/>8.4.4 Style Resolution Processing</h4><p>The process of style resolution is defined herein as the procedure
-(and results thereof) for resolving (determining) the computed values
-of all style properties that apply to content and layout elements:</p><ul><li><p><a href="#semantics-style-resolution-processing-definitions"><b>8.4.4.1 Conceptual Definitions</b></a></p></li><li><p><a href="#semantics-style-resolution-processing-sss"><b>8.4.4.2 Specified Style Set Processing</b></a></p></li><li><p><a href="#semantics-style-resolution-processing-css"><b>8.4.4.3 Computed Style Set Processing</b></a></p></li><li><p><a href="#semantics-style-resolution-process-overall"><b>8.4.4.4 Style Resolution Process</b></a></p></li></ul><p>The process described here forms an integral sub-process of
-<a href="#semantics-region-layout"><b>9.3 Region Layout and Presentation</b></a>.</p><div class="div4">
-<h5><a name="semantics-style-resolution-processing-definitions" id="semantics-style-resolution-processing-definitions"/>8.4.4.1 Conceptual Definitions</h5><p>For the purpose of interpreting the style resolution processing
-model specified below, the following conceptual definitions apply:</p><dl><dt class="label">[style property]</dt><dd><p>a style property, <em>P</em>, is considered to consist of a
-tuple <code>[name, value]</code>, where the name of the
-property is a tuple <code>[namespace value,
-unqualified name]</code> and the value of the property is a
-tuple <code>[category, type, value expression]</code></p><table summary="HTML Table" id="conceptual-definition-example-style-property" class="example"><caption>Example – conceptual style property</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-[
-  ["http://www.w3.org/ns/ttml#styling", "color"],
-  ["specified", <em>color</em>, "red"]
-]
-</pre></div>
-</td></tr></tbody></table><p/></dd><dt class="label">[style (property) set]</dt><dd><p>a style (property) set consists of an unordered collection of style
-properties, where no two style properties within the set have an
-identical name, where by "identical name" is meant equality of
-namespace value of name tuple and unqualified name of name tuple;</p><p>in a specified style (property) set, the category of each style
-property is "specified"; a specified style (property) set of an
-element <em>E</em> is referred to as <em>SSS(E)</em>;</p><table summary="HTML Table" id="conceptual-definition-example-specified-style-set" class="example"><caption>Example – conceptual (specified) style (property) set</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-{
-  [
-    ["http://www.w3.org/ns/ttml#styling", "backgroundColor"],
-    ["specified", <em>color</em>, 0x00FF00 ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "color"],
-    ["specified", <em>color</em>, "red" ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "fontSize"],
-    ["specified", <em>length</em>, "1c" ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "lineHeight"],
-    ["specified", <em>length</em>, "117%" ]
-  ]
-}
-</pre></div>
-</td></tr></tbody></table><p>in a computed style (property) set, the category of each style
-property is either "specified" or "computed"; a computed style (property) set of an element
-<em>E</em> is referred to as <em>CSS(E)</em>;</p><table summary="HTML Table" id="conceptual-definition-example-computed-style-set" class="example"><caption>Example – conceptual (computed) style (property) set</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-{
-  [
-    ["http://www.w3.org/ns/ttml#styling", "backgroundColor"],
-    ["specified", <em>color</em>, 0x00FF00 ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "color"],
-    ["computed", <em>color</em>, 0xFF0000 ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "fontSize"],
-    ["computed", <em>length</em>, "24px" ]
-  ],
-  [
-    ["http://www.w3.org/ns/ttml#styling", "lineHeight"],
-    ["computed", <em>length</em>, "28px" ]
-  ]
-}
-</pre></div>
-</td></tr></tbody></table><p/></dd><dt class="label">[style (property) merging]</dt><dd><p>a style property <em>P<sub>new</sub></em> is merged into a
-style (property) set, <em>SS</em>, as follows: if a style property
-<em>P<sub>old</sub></em> is already present in <em>SS</em>
-where the name of <em>P<sub>new</sub></em> is identical to the
-name of <em>P<sub>old</sub></em>, then replace
-<em>P<sub>old</sub></em> in <em>SS</em> with
-<em>P<sub>new</sub></em>; otherwise, add
-<em>P<sub>new</sub></em> to <em>SS</em>;</p></dd><dt class="label">[style (property) set merging]</dt><dd><p>a style (property) set <em>SS<sub>new</sub></em> is merged into
-an existing style (property) set <em>SS<sub>old</sub></em> as
-follows: for each style property <em>P<sub>new</sub></em> in
-<em>SS<sub>new</sub></em>, merge <em>P<sub>new</sub></em> into
-<em>SS<sub>old</sub></em>;</p></dd></dl></div><div class="div4">
-<h5><a name="semantics-style-resolution-processing-sss" id="semantics-style-resolution-processing-sss"/>8.4.4.2 Specified Style Set Processing</h5><p>The specified style set <em>SSS</em> of an element or
-anonymous span <em>E</em>,
-<em>SSS(E)</em>, is determined according to the following ordered
-rules:</p><ol class="enumar"><li><p><span class="strong">[initialization]</span> initialize
-the specified style set <em>SSS</em> of <em>E</em> to the
-empty set;</p></li><li><p><span class="strong">[referential and chained referential
-styling]</span> for each <code>style</code> element <em>S<sub>REF</sub></em>
-referenced by a <code>style</code> attribute specified on
-<em>E</em>, and in the order specified in the <code>style</code>
-attribute, then, if <em>S<sub>REF</sub></em> is a descendant
-of a <code>styling</code> element,
-merge the specified style set of
-<em>S<sub>REF</sub></em>, <em>SSS(S<sub>REF</sub>)</em>, into
-the specified style set of <em>E</em>,
-<em>SSS(E)</em>;</p></li><li><p><span class="strong">[nested styling]</span> for each
-nested <code>style</code> element child <em>S<sub>NEST</sub></em> of
-<em>E</em>, and in the specified order of child elements, merge
-the specified style set of <em>S<sub>NEST</sub></em>,
-<em>SSS(S<sub>NEST</sub>)</em>, into the specified style set of
-<em>E</em>, <em>SSS(E)</em>;</p></li><li><p><span class="strong">[inline styling]</span> for each
-style property <em>P</em> expressed as a specified styling
-attribute of <em>E</em>,
-merge <em>P</em> into the specified style
-set of <em>E</em>, <em>SSS(E)</em>;</p></li><li><p><span class="strong">[implicit inheritance]</span> if the
-element type of <em>E</em> is not the styling element type
-<code>style</code>, then for each inheritable style property
-<em>P<sub>INH</sub></em> in the set of style properties defined
-above in <a href="#styling-attribute-vocabulary"><b>8.2 Styling Attribute Vocabulary</b></a>, perform the
-following ordered sub-steps:</p><ol class="enumla"><li><p>if <em>P<sub>INH</sub></em> is present in the specified
-style set of <em>E</em>, <em>SSS(E)</em>, then continue to the
-next inheritable style property;</p></li><li><p>if the element type of <em>E</em> is the layout element
-type <code>region</code>, then set <em>P′</em> to the initial value of
-property <em>P</em>, where the initial value of a property is
-determined according to the specific property definition found above
-in <a href="#styling-attribute-vocabulary"><b>8.2 Styling Attribute Vocabulary</b></a>;</p></li><li><p>if the element type of <em>E</em> is a content element
-type or anonymous span, then set <em>P′</em> to the result of
-looking up the value of <em>P</em> in the computed style set of
-the immediate ancestor element of <em>E</em>, i.e.,
-<em>CSS(PARENT(E))</em>;</p></li><li><p>if the value of <em>P′</em> is not undefined, then merge
-<em>P′</em> into the specified style set of <em>E</em>,
-<em>SSS(E)</em>.</p></li></ol></li></ol></div><div class="div4">
-<h5><a name="semantics-style-resolution-processing-css" id="semantics-style-resolution-processing-css"/>8.4.4.3 Computed Style Set Processing</h5><p>The computed style set <em>CSS</em> of an element or
-anonymous span <em>E</em>,
-<em>CSS(E)</em>, is determined according to the following ordered
-rules:</p><ol class="enumar"><li><p><span class="strong">[resolve specified styles]</span>
-determine (obtain) the specified style set <em>SSS</em> of
-<em>E</em>, namely, <em>SSS(E)</em>, in accordance with
-<a href="#semantics-style-resolution-processing-sss"><b>8.4.4.2 Specified Style Set Processing</b></a>;</p></li><li><p><span class="strong">[initialization]</span>
-initialize <em>CSS(E)</em> to a (deep) copy of
-<em>SSS(E)</em>;</p></li><li><p><span class="strong">[filter]</span> if
-<em>E</em> is a <code>style</code> element, then return
-<em>CSS(E)</em> as the resulting computed style set without
-further resolution; otherwise, continue with the next rule;</p></li><li><p><span class="strong">[relative value resolution]</span> for each
-style property <em>P</em> in <em>CSS(E)</em>, where the value
-type of <em>P</em> is relative, perform the following ordered
-sub-steps:</p><ol class="enumla"><li><p>replace the relative value of <em>P</em> with an
-equivalent, non-relative (computed) value;</p></li><li><p>set the category of <em>P</em> to "computed";</p></li></ol></li></ol><div class="note"><p class="prefix"><b>Note:</b></p><p>As a result of the filtering rule above, the computed style set of
-a <code>style</code> element includes only specified values, in which case
-relative value expressions remain relative; consequently, the
-resolution of relative value expressions (that may be assigned by
-means of referential style association) always takes place in the
-context of a layout or content element which has a presentation
-context, and not in the non-presentation, declaration context
-of a referentiable <code>style</code> element.</p></div></div><div class="div4">
-<h5><a name="semantics-style-resolution-process-overall" id="semantics-style-resolution-process-overall"/>8.4.4.4 Style Resolution Process</h5><p>The top-level style resolution process is defined as follows: using
-a preorder traversal of each element and anonymous span,
-<em>E</em>, of an intermediate synchronic document,
-<em>DOC<sub>inter</sub></em>, perform the following ordered
-sub-steps:</p><ol class="enumar"><li><p><span class="strong">[filter]</span> if the element type
-of <em>E</em> is not the styling element type <code>style</code>, is
-not the layout element type <code>region</code>, and is not one of the
-content element types <code>body</code>, <code>div</code>, <code>p</code>,
-<code>span</code>, <code>br</code>, or anonymous span, then continue to the
-next element in the preorder traversal;</p></li><li><p> <span class="strong">[resolve computed styles]</span>
-determine (obtain) the computed style set <em>CSS</em> of
-<em>E</em>, namely, <em>CSS(E)</em>, in accordance with
-<a href="#semantics-style-resolution-processing-css"><b>8.4.4.3 Computed Style Set Processing</b></a>.</p></li></ol></div></div></div></div><div class="div1">
-<h2><a name="layout" id="layout"/>9 Layout</h2><p>This section specifies the <em>layout</em> matter of the core
-vocabulary catalog, where
-layout is to be understood as a separable layer of information that applies to
-content and that denotes authorial intentions about the presentation of
-that content.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>The two layers of layout and style matter are considered to be independently
-separable. Layout matter specifies one or more spaces or areas into
-which content is intended to be presented, while style matter specifies the manner in
-which presentation occurs within the layout.</p><p>In certain cases, a content author may choose to embed (inline) style matter directly
-into layout or content matter. In such cases, an alternative 
-exists – use of referential styling –
-in which the style
-matter is not embedded (inlined).</p></div><div class="div2">
-<h3><a name="layout-element-vocabulary" id="layout-element-vocabulary"/>9.1 Layout Element Vocabulary</h3><p>The following elements specify the structure and principal layout aspects of a
-document instance:</p><ul><li><p><a href="#layout-vocabulary-layout"><b>9.1.1 layout</b></a></p></li><li><p><a href="#layout-vocabulary-region"><b>9.1.2 region</b></a></p></li></ul><div class="div3">
-<h4><a name="layout-vocabulary-layout" id="layout-vocabulary-layout"/>9.1.1 layout</h4><p>The <code>layout</code> element is a container element used to group
-layout matter, including metadata that applies to layout matter.</p><p>The <code>layout</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group, followed by
-zero or more <code>region</code> elements.</p><table summary="HTML Table" id="elt-syntax-layout" class="syntax"><caption>XML Representation – Element Information Item: layout</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;layout
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#layout-vocabulary-region">region</a>*
-&lt;/layout&gt;
-</pre></div>
-</td></tr></tbody></table><p>To the extent that time semantics apply to the content of the
-<code>layout</code> element, the implied time interval of this element is
-defined to be coterminous with the external time interval.</p></div><div class="div3">
-<h4><a name="layout-vocabulary-region" id="layout-vocabulary-region"/>9.1.2 region</h4><p>The <code>region</code> element is used to define a space or area into which content is
-to be flowed for the purpose of presentation.</p><p>In addition, and in accordance with
-<a href="#semantics-style-inheritance-region"><b>8.4.2.2 Region Style Inheritance</b></a>, 
-the <code>region</code> element may be used to specify inheritable style properties to be
-inherited by content that is flowed into it.</p><p>The <code>region</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group,
-followed by zero or more
-elements in the <code>Animation.class</code> element group,
-followed by
-zero or more <code>style</code> elements.</p><p>Any metadata specified by children in the <code>Metadata.class</code>
-element group applies semantically to the <code>region</code> element and its descendants as a whole.
-Any animation elements specified by children in the <code>Animation.class</code>
-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><table summary="HTML Table" id="elt-syntax-region" 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>
-  <a href="#timing-attribute-dur">dur</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#timing-attribute-end">end</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#style-attribute-style">style</a> = IDREFS
-  <a href="#timing-attribute-timeContainer">timeContainer</a> = (<em>par</em>|<em>seq</em>)
-  <a href="#metadata-attribute-role">ttm:role</a> = string
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-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-table">Metadata.class</a>*, <a href="#element-vocab-group-table">Animation.class</a>*, <a href="#styling-vocabulary-style">style</a>*
-&lt;/region&gt;
-</pre></div>
-</td></tr></tbody></table><p>If <code>begin</code> and (or) <code>end</code> attributes are specified on a
-<code>region</code> element, then they specify the beginning and (or) ending points
-of a time interval during which the region is eligible for activation and with
-respect to which animation child elements of the region are timed.
-If specified, these begin and end points are relative to the time
-interval of the nearest ancestor element associated with a time
-interval, irregardless of whether that interval is explicit or implied.</p><p>The nearest ancestor element of a <code>region</code> element that is associated
-with a time interval is the document instance's root <code>tt</code> element.</p><p>If a <code>dur</code> attribute is specified on the <code>region</code> element, then it
-specifies the simple duration of the region.</p><p>For the purpose of determining the semantics of presentation processing, a
-region that is temporally inactive must not produce any visible marks when
-presented on a visual medium.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <code>region</code> element may be associated with a time interval for two
-purposes: (1) in order to temporally bound the presentation of the region and
-its content, and (2) to provide a temporal context in which animations of region
-styles may be effected.</p><p>For example, an author may wish a region that is otherwise empty, but
-may have a visible background color to be presented starting at some time and
-continuing over the region's duration.  The simple duration of the region serves
-additionally to scope the presentation effects of content that is targeted to the
-region. An author may also wish to move a region within the root container
-extent or change a region's background color by means of animation effects. In
-both of these cases, it is necessary to posit an active time interval for a
-region.</p></div><p>If no <code>timeContainer</code> attribute is specified on
-a <code>region</code> element, then it must be interpreted as having
-<em>parallel</em> time containment semantics.</p><p>If a <a href="#metadata-attribute-role"><code>ttm:role</code></a> attribute is
-specified on a <code>region</code> element, then it must adhere to the
-value syntax defined by <a href="#metadata-attribute-role-syntax"><b>Syntax Representation – ttm:role</b></a>, and where the role(s) identified
-by this attribute expresses the semantic role(s) of the region
-independently from the semantic role(s) of any content targeted to
-(associated with) the region.</p></div></div><div class="div2">
-<h3><a name="layout-attribute-vocabulary" id="layout-attribute-vocabulary"/>9.2 Layout Attribute Vocabulary</h3><p>This section defines the <a href="#layout-attribute-region"><b>9.2.1 region</b></a> attribute used with content elements.</p><div class="div3">
-<h4><a name="layout-attribute-region" id="layout-attribute-region"/>9.2.1 region</h4><p>The <code>region</code> attribute is used to reference a <code>region</code>
-element which defines a space or area into which a content element is intended to be flowed.</p><p>The <code>region</code> attribute may be specified by an instance of the following
-element types:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#semantics-region-layout"><b>9.3 Region Layout and Presentation</b></a> below for further information on content
-flow in a region.</p></div></div></div><div class="div2">
-<h3><a name="semantics-region-layout" id="semantics-region-layout"/>9.3 Region Layout and Presentation</h3><p>This section defines the semantics of region layout and
-presentation in terms of a standard processing model as
-follows:</p><ul><li><p><a href="#semantics-default-region"><b>9.3.1 Default Region</b></a></p></li><li><p><a href="#semantics-region-layout-step-1"><b>9.3.2 Intermediate Synchronic Document Construction</b></a></p></li><li><p><a href="#semantics-region-layout-step-2"><b>9.3.3 Synchronic Flow Processing</b></a></p></li><li><p><a href="#semantics-region-layout-example"><b>9.3.4 Elaborated Example (Informative)</b></a></p></li></ul><p>Any
-implementation is permitted provided that the externally observable
-results are consistent with the results produced by this model.
-</p><div class="div3">
-<h4><a name="semantics-default-region" id="semantics-default-region"/>9.3.1 Default Region</h4><p>If a TTML document instance does not specify a
-<a href="#layout-vocabulary-region"><code>region</code></a> element,
-then a <em>default region</em> is implied with the following characteristics:</p><ul><li><p>the identity of the default region is considered to be anonymous;</p></li><li><p>the extent of the default region is the same as the root container
-region;</p></li><li><p>the temporal interval of the default region is the same as temporal
-interval of the document instance;</p></li></ul><p>Furthermore, if no <a href="#layout-vocabulary-region"><code>region</code></a> element was
-specified, then the <a href="#layout-attribute-region"><code>region</code></a> attribute must
-not be specified on any content element in the document
-instance.</p><p>If a default region is implied for a given document instance, then
-the <a href="#document-structure-vocabulary-body"><code>body</code></a> element
-is implicitly targeted to (associated with) the default region.</p><p>When implying a default region, the document instance is to be
-treated as if a <a href="#layout-vocabulary-region"><code>region</code></a> element and its
-parent <a href="#layout-vocabulary-layout"><code>layout</code></a>
-element were specified in a <a href="#document-structure-vocabulary-head"><code>head</code></a>
-element, and a matching <a href="#layout-attribute-region"><code>region</code></a> attribute were
-specified on the <a href="#document-structure-vocabulary-body"><code>body</code></a> element
-as shown in the following example:</p><table summary="HTML Table" id="semantics-default-region-example" class="example"><caption>Example – Implied Default Region</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"&gt;
-  &lt;head&gt;
-    <span class="strong">&lt;layout&gt;
-      &lt;region xml:id="anonymous"/&gt;
-    &lt;/layout&gt;</span>
-  &lt;/head&gt;
-  &lt;body <span class="strong">region="anonymous"</span>/&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a default <code>region</code> element and <code>region</code>
-attribute are implied. In addition, a <code>layout</code> container element is implied for
-the implied <code>region</code> element.</p></div></div><div class="div3">
-<h4><a name="semantics-region-layout-step-1" id="semantics-region-layout-step-1"/>9.3.2 Intermediate Synchronic Document Construction</h4><p>For the purposes of performing presentation processing, the active time
-duration of a document instance is divided into a sequence of time coordinates where at
-each time coordinate, some element becomes temporally active or inactive,
-then, at each such time coordinate, a document
-instance is mapped from its original, source
-form, <em>DOC<sub>source</sub></em>, 
-to an intermediate
-synchronic document form,
-<em>DOC<sub>inter</sub></em>, as follows:</p><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>;</p></li><li><p>if the pruned sub-tree is non-empty, then reparent it to the <em>R</em>
-element;</p></li><li><p>finally, after completing the above steps, prune the original <code>body</code>
-element from the intermediate document, then prune all <code>region</code>,
-<code>begin</code>, <code>end</code>, and <code>dur</code> attributes, which are no
-longer semantically relevant;</p></li></ol><p>A content element is associated with a region according
-to the following ordered rules, where the first rule satisfied
-is used and remaining rules are skipped:</p><ol class="enumar"><li><p>if the element specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute,
-then the element is associated with the region referenced by that
-attribute;</p></li><li><p>if some ancestor of that element specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute,
-then the element is associated with the region referenced by the most
-immediate ancestor that specifies this attribute;</p></li><li><p> if the element contains a descendant element that
-specifies a <a href="#layout-attribute-region"><code>region</code></a> attribute,
-then the element is associated with the region referenced by that
-attribute;</p></li><li><p>if a default region was implied (due to the absence of any
-<a href="#layout-vocabulary-region"><code>region</code></a> element),
-then the element is associated with the default region;</p></li><li><p>the element is not associated with any region.</p></li></ol><p>The pseudo-code shown in <a href="#content-hierarchy-region-mapping"><b>Example – Content Hierarchy Region Mapping</b></a>
-provides one possible algorithm that implements these processing steps.</p><table summary="HTML Table" id="content-hierarchy-region-mapping" class="example"><caption>Example – Content Hierarchy Region Mapping</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-PREPARE-CONTENT ( D ) := 
-  foreach R in SELECT ( D, "/tt/head/layout/region" )
-    if TEMPORALLY-ACTIVE? ( R )
-      APPEND-CHILDREN ( R, SELECT ( D, "/tt/body" ) )
-      foreach E in POSTORDER-TRAVERSE ( R )
-        if ! CONTENT-ELEMENT? ( E ) or ! TEMPORALLY-ACTIVE? ( E ) or EMPTY? ( E ) or REGION-OF ( E ) != R
-            then PRUNE ( E )
-  PRUNE ( SELECT ( D, "/tt/body" ) )
-  PRUNE ( SELECT ( D, "//*/@region" ) )
-  PRUNE ( SELECT ( D, "//*/@begin" ) )
-  PRUNE ( SELECT ( D, "//*/@end" ) )
-  PRUNE ( SELECT ( D, "//*/@dur" ) )
- 
-REGION-OF ( E ) :=
-  if NULL? ( E )
-    return NULL
-  else if HAS-ATTRIBUTE? ( E, "region" )
-    return VALUE-OF-ATTRIBUTE ( E, "region" )
-  else
-    return REGION-OF ( PARENT-OF ( E ) )
-</pre></div>
-</td></tr></tbody></table><p>The result of performing the processing described above will be a sequence of
-<em>N</em> intermediate  synchronic
-document instances,
-<em>DOC<sub><span>inter<sub>0</sub></span></sub></em> …
-<em>DOC<sub><span>inter<sub>N−1</sub></span></sub></em>.</p></div><div class="div3">
-<h4><a name="semantics-region-layout-step-2" id="semantics-region-layout-step-2"/>9.3.3 Synchronic Flow Processing</h4><p>Subsequent to performing a temporal (synchronic) slice and subsequent
-remapping of regionally selected content hierarchy, the resulting intermediate
-synchronic document is subjected to a flow transformation step that produces 
-a rooted flow object tree represented as 
-an XSL FO document instance as defined by <a href="#xsl11">[XSL 1.1]</a>,
-and semantically extended by TTML specific style properties that have no XSL
-FO counterpart.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In this section, the use of XSL FO is intended to be conceptual only, employed
-solely for the purpose of defining the normative presentation semantics of
-TTML. An actual implementation of this algorithm is not required to create or process
-XSL FO representations. In particular, it is possible to implement these semantics
-using alternative presentation models, such as Cascading Style Sheets (CSS).</p></div><p>Each intermediate synchronic  document produced by <a href="#semantics-region-layout-step-1"><b>9.3.2 Intermediate Synchronic Document Construction</b></a> is mapped 
-
-to a styled document <em>F</em> consistent with an XSL FO document instance, as follows</p><ol class="enumar"><li><p>perform the following ordered sub-steps to create anonymous spans:</p><ol class="enumla"><li><p>for each significant text node in a content element,
-synthesize an anonymous span to enclose the text node, substituting
-the new anonymous span for the original text node child in its sibling
-and parent hierarchy;</p></li><li><p>for each contiguous sequence of anonymous spans, replace the
-sequence with a single anonymous span which contains a sequence of
-text nodes representing the individual text node children of the
-original sequence of anonymous spans;</p></li><li><p>for each span element whose child is a single anonymous span,
-replace the anonymous span with its sequence of child text
-nodes;</p></li></ol></li><li><p>resolve styles according to <a href="#semantics-style-resolution-process-overall"><b>8.4.4.4 Style Resolution Process</b></a>;</p></li><li><p>map the <code>tt</code> element to an <code>fo:root</code> element, populated
-initially with an <code>fo:layout-master-set</code> element that contains a valid
-<code>fo:simple-page-master</code> that, in turn, contains an
-<code>fo:region-body</code> child, where the root container extent expressed on the
-<code>tt</code> element is mapped to <code>page-width</code> and
-<code>page-height</code> attributes on the <code>fo:simple-page-master</code>
-element;</p></li><li><p>map the <code>layout</code> element to an <code>fo:page-sequence</code> element and a
-child <code>fo:flow</code> element that reference the page master and page region
-defined by the simple page master produced above;</p></li><li><p>map each non-empty <code>region</code> element to an <code>fo:block-container</code>
-element with an <code>absolute-position</code> attribute with value
-<code>absolute</code>, and where the region's position and extent are mapped to equivalent
-<code>top</code>, <code>left</code>, <code>width</code>, and <code>height</code>
-attributes;</p></li><li><p>for each <code>body</code>, <code>div</code>, and <code>p</code> element that is not
-associated with a <code>tts:display</code> style property with the value
-<code>none</code>, map the element to a distinct <code>fo:block</code> element,
-populating the style properties of <code>fo:block</code> by using the computed
-style set associated with each original TTML content element;</p></li><li><p>for the resulting <code>fo:block</code> formatting object
-produced in the previous step that corresponds to the <code>body</code>
-element, synthesize and append to the end of its children an empty
-  <code>fo:block</code> with the following attributes:
-<code>space-after.optimum</code>, <code>space-after.maximum</code>, and
-<code>space-after.conditionality</code>, where the value of the former
-two attributes is the height or width of the containing
-<code>fo:block-container</code> element, whichever of these is designated
-as the block progression dimension, and where the value of the last is
-<code>retain</code>;</p></li><li><p>for each <code>span</code> element that is not
-associated with a <code>tts:display</code> style property with the value
-<code>none</code> and for each anonymous
-span that is a child of a <code>p</code> or <code>span</code> element,
-map the element or
-sequence of character items to a distinct <code>fo:inline</code> element,
-populating the style properties of <code>fo:inline</code> by using the computed
-style set associated with each original TTML content element
-or anonymous span;</p></li><li><p>for each <code>br</code> element that is not
-associated with a <code>tts:display</code> style property with the value
-<code>none</code>, map the element to
-a distinct <code>fo:character</code> element having the following
-properties:</p><ul><li><p><code>character="&amp;#x000A;"</code></p></li><li><p><code>suppress-at-line-break="retain"</code></p></li></ul></li><li><p>for each TTML style property attribute in some computed
-style set that
-has no counterpart in <a href="#xsl11">[XSL 1.1]</a>, map that attribute directly through
-to the relevant formatting object produced by the input TTML content element to
-which the style property applies;</p></li><li><p>optionally, synthesize a unique <code>id</code> attribute on each resulting
-formatting object element that relates that element to the input element that
-resulted in that formatting object element;</p></li></ol><p>For each resulting document instance F, if processing requires presentation on a 
-  visual medium, then apply formatting and rendering semantics consistent with that 
-  prescribed by <a href="#xsl11">[XSL 1.1]</a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In an XSL FO area tree produced by formatting <em>F</em> using 
-an <a href="#xsl11">[XSL 1.1]</a> formatting processor, 
-the <code>page-viewport-area</code>,
-which is generated by <code>fo:page-sequence</code> element by
-reference to the sole generated <code>fo:simple-page-master</code>
-element, would correspond to the <em>root container region</em> defined
-above in <a href="#definitions"><b>2 Definitions</b></a>.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>
-  Due to the possible presence of TTML style properties or style property values
-  in a given TTML document instance for which there is no <a href="#xsl11">[XSL 1.1]</a> counterpart,
-  Implementors should recognize that it is the layout model of <a href="#xsl11">[XSL 1.1]</a> that is being referenced
-  by this specification, not the requirement to use a compliant <a href="#xsl11">[XSL 1.1]</a> formatting processor,
-  since such would not necessarily be sufficient to satisfy the full presentation semantics
-  defined by this specification, and would contain a large number of features not needed to
-  implement the presentation semantics of TTML.</p></div></div><div class="div3">
-<h4><a name="semantics-region-layout-example" id="semantics-region-layout-example"/>9.3.4 Elaborated Example (Informative)</h4><p>An example of the processing steps described above is elaborated below, starting with <a href="#region-mapping-example-1-s"><b>Example – Sample Source Document</b></a>.</p><table summary="HTML Table" id="region-mapping-example-1-s" class="example"><caption>Example – Sample Source Document</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-  &lt;body xml:id="b1"&gt;
-    &lt;div xml:id="d1" begin="0s" dur="2s"&gt;
-      &lt;p xml:id="p1" region="r1"&gt;Text 1&lt;/p&gt;
-      &lt;p xml:id="p2" region="r2"&gt;Text 2&lt;/p&gt;
-    &lt;/div&gt;
-    &lt;div xml:id="d2" begin="1s" dur="2s"&gt;
-      &lt;p xml:id="p3" region="r2"&gt;Text 3&lt;/p&gt;
-      &lt;p xml:id="p4" region="r1"&gt;Text 4&lt;/p&gt;
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>In the above document, the content hierarchy consists of two divisions, each
-containing two paragraphs. This content is targeted (selected into) 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
-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 selected into 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 TTML document instances,
-but rather, are representations of possible internal processing states used for
-didactic purposes.</p></div><table summary="HTML Table" id="region-mapping-example-1-i0" class="example"><caption>Example – Intermediate Document – [0s,1s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-1"&gt;
-          &lt;div xml:id="d1-1"&gt;
-            &lt;p xml:id="p1"&gt;Text 1&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-2"&gt;
-          &lt;div xml:id="d1-2"&gt;
-            &lt;p xml:id="p2"&gt;Text 2&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>
-  
-  An XSL FO document instance that would yield rendering consistent with TTML, and 
-  which may be produced by performing flow processing upon the first intermediate 
-  document is illustrated below.
-</p><table summary="HTML Table" id="region-mapping-example-1-f0" class="example"><caption>Example – XSL FO Document – [0s,1s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"&gt;
-  &lt;fo:layout-master-set&gt;
-    &lt;fo:simple-page-master master-name="m1"
-      page-width="640px" page-height="480px"&gt;
-      &lt;fo:region-body/&gt;
-    &lt;/fo:simple-page-master&gt;
-  &lt;/fo:layout-master-set&gt;
-  &lt;fo:page-sequence master-reference="m1"&gt;
-    &lt;fo:flow flow-name="xsl-region-body"&gt;
-      &lt;!-- region (r1) --&gt;
-      &lt;fo:block-container id="r1" absolute-position="absolute"
-        left="10px" top="100px" width="620px" height="96px"
-        background-color="black" display-align="center"&gt;
-        &lt;!-- body (b1) --&gt;
-        &lt;fo:block id="b1-1"&gt;
-          &lt;!-- div (d1) --&gt;
-          &lt;fo:block id="d1-1"&gt;
-            &lt;!-- p (p1) --&gt;
-            &lt;fo:block id="p1" text-align="center"&gt;
-              &lt;fo:inline font-size="40px" font-weight="bold"
-              color="red"&gt;Text 1&lt;/fo:inline&gt;
-            &lt;/fo:block&gt;
-          &lt;/fo:block&gt;
-          &lt;!-- body's space filler -&gt;
-          &lt;fo:block
-            space-after.optimum="96px"
-            space-after.maximum="96px"
-            space-after.conditionality="retain"/&gt;
-        &lt;/fo:block&gt;
-      &lt;/fo:block-container&gt;
-      &lt;!-- region (r2) --&gt;
-      &lt;fo:block-container id="r2" absolute-position="absolute"
-        left="10px" top="300px" width="620px" height="96px"
-        background-color="black" display-align="center"&gt;
-        &lt;!-- body (b1) --&gt;
-        &lt;fo:block id="b1-2"&gt;
-          &lt;!-- div (d1) --&gt;
-          &lt;fo:block id="d1-2"&gt;
-            &lt;!-- p (p2) --&gt;
-            &lt;fo:block id="p2" text-align="center"&gt;
-              &lt;fo:inline font-size="40px" font-weight="bold"
-              color="yellow"&gt;Text 2&lt;/fo:inline&gt;
-            &lt;/fo:block&gt;
-          &lt;/fo:block&gt;
-          &lt;!-- body's space filler -&gt;
-          &lt;fo:block
-            space-after.optimum="96px"
-            space-after.maximum="96px"
-            space-after.conditionality="retain"/&gt;
-        &lt;/fo:block&gt;
-      &lt;/fo:block-container&gt;
-    &lt;/fo:flow&gt;
-  &lt;/fo:page-sequence&gt;
-&lt;/fo:root&gt;
-</pre></div>
-</td></tr></tbody></table><p>The following, second intermediate document shows the synchronic state at
-time interval [1,2), at 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 selected into region <code>r1</code>
-and paragraphs <code>p2</code> and <code>p3</code> (and their ancestors) are
-selected into region <code>r2</code>.</p><table summary="HTML Table" id="region-mapping-example-1-i1" class="example"><caption>Example – Intermediate Document – [1s,2s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-1"&gt;
-          &lt;div xml:id="d1-1"&gt;
-            &lt;p xml:id="p1"&gt;Text 1&lt;/p&gt;
-          &lt;/div&gt;
-          &lt;div xml:id="d2-1"&gt;
-            &lt;p xml:id="p4"&gt;Text 4&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-2"&gt;
-          &lt;div xml:id="d1-2"&gt;
-            &lt;p xml:id="p2"&gt;Text 2&lt;/p&gt;
-          &lt;/div&gt;
-          &lt;div xml:id="d2-2"&gt;
-            &lt;p xml:id="p3"&gt;Text 3&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><p>The following, third intermediate document shows the synchronic state at time
-interval [2,3), at which time only division <code>d2</code> is temporally active,
-and where paragraphs <code>p4</code> and <code>p3</code> (and their ancestors)
-are selected into regions <code>r1</code> and <code>r2</code>, respectively.</p><table summary="HTML Table" id="region-mapping-example-1-i2" class="example"><caption>Example – Intermediate Document – [2s,3s)</caption><tbody><tr><td>
-<div class="exampleInner"><pre>&lt;tt tts:extent="640px 480px" xml:lang="en"
-  xmlns="http://www.w3.org/ns/ttml"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;head&gt;
-    &lt;layout&gt;
-      &lt;region xml:id="r1"&gt;
-        &lt;style tts:origin="10px 100px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="red"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-1"&gt;
-          &lt;div xml:id="d2-1"&gt;
-            &lt;p xml:id="p4"&gt;Text 4&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-      &lt;region xml:id="r2"&gt;
-        &lt;style tts:origin="10px 300px"/&gt;
-        &lt;style tts:extent="620px 96px"/&gt;
-        &lt;style tts:fontSize="40px"/&gt;
-        &lt;style tts:fontWeight="bold"/&gt;
-        &lt;style tts:backgroundColor="black"/&gt;
-        &lt;style tts:color="yellow"/&gt;
-        &lt;style tts:textAlign="center"/&gt;
-        &lt;style tts:displayAlign="center"/&gt;
-        &lt;body xml:id="b1-2"&gt;
-          &lt;div xml:id="d2-2"&gt;
-            &lt;p xml:id="p3"&gt;Text 3&lt;/p&gt;
-          &lt;/div&gt;
-        &lt;/body&gt;
-      &lt;/region&gt;
-    &lt;/layout&gt;
-  &lt;/head&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table></div></div><div class="div2">
-<h3><a name="semantics-line-layout" id="semantics-line-layout"/>9.4 Line Layout</h3><p>If a profile that applies to a document instance
-requires use of the <a href="#feature-lineBreak-uax14">#lineBreak-uax14</a> feature
-(i.e., the value attribute for the feature is specified as <code>use</code>), then
-the recommendations defined by <a href="http://www.unicode.org/unicode/reports/tr14/#Algorithm">Line
-Breaking Algorithm</a> <a href="#uax14">[UAX14]</a> apply when performing
-line layout on the content of the document instance.</p></div></div><div class="div1">
-<h2><a name="timing" id="timing"/>10 Timing</h2><p>This section specifies the <em>timing</em> matter of the core
-vocabulary catalog, where
-timing is to be understood as a separable layer of information that applies to
-content and that denotes authorial intentions about the temporal presentation of
-that content.</p><div class="div2">
-<h3><a name="timing-element-vocabulary" id="timing-element-vocabulary"/>10.1 Timing Element Vocabulary</h3><p>No timing related element vocabulary is defined for use in the core
-vocabulary catalog.</p></div><div class="div2">
-<h3><a name="timing-attribute-vocabulary" id="timing-attribute-vocabulary"/>10.2 Timing Attribute Vocabulary</h3><p>This section defines the following basic timing attributes for use with timed elements:</p><ul><li><p><a href="#timing-attribute-begin"><b>10.2.1 begin</b></a></p></li><li><p><a href="#timing-attribute-end"><b>10.2.2 end</b></a></p></li><li><p><a href="#timing-attribute-dur"><b>10.2.3 dur</b></a></p></li></ul><p>In addition, this section defines the <a href="#timing-attribute-timeContainer"><b>10.2.4 timeContainer</b></a> attribute for use with timed elements
-that serve simultaneously as timing containers.</p><div class="div3">
-<h4><a name="timing-attribute-begin" id="timing-attribute-begin"/>10.2.1 begin</h4><p>The <code>begin</code> attribute is used to specify the begin
-point of a temporal interval associated with a timed element. If
-specified, the value of a <code>begin</code> attribute must adhere to
-a &lt;timeExpression&gt; specification as defined by <a href="#timing-value-timeExpression"><b>10.3.1 &lt;timeExpression&gt;</b></a>.</p><p>The begin point of a temporal interval is included in the
-interval; i.e., the interval is left-wise closed.</p><p>The semantics of the <code>begin</code> attribute are those defined
-by <a href="#smil21">[SMIL 2.1]</a>, § 10.4.1,
-while taking into account any overriding semantics defined by this specification.</p></div><div class="div3">
-<h4><a name="timing-attribute-end" id="timing-attribute-end"/>10.2.2 end</h4><p>The <code>end</code> attribute is used to specify the ending point
-of a temporal interval associated with a timed element. If
-specified, the value of an <code>end</code> attribute must adhere to a
-&lt;timeExpression&gt; specification as defined by <a href="#timing-value-timeExpression"><b>10.3.1 &lt;timeExpression&gt;</b></a>.</p><p>The ending point of a temporal interval is not included in the
-interval; i.e., the interval is right-wise open.</p><p>The presentation effects of a non-empty active
-temporal interval include the frame immediately prior to the frame
-(or tick) equal to or immediately following the time specified by the ending
-point, but do not extend into this latter frame (or tick).</p><div class="note"><p class="prefix"><b>Note:</b></p><p>For example, if an active interval is [10s,10.33333s), and the
-frame rate is 30 frames per second, then the presentation effects of the interval
-are limited to frames 300 through 309 only (assuming that 0s corresponds
-with frame 0). The same holds if the active interval is specified
-as [300f,310f).</p></div><p>The semantics of the <code>end</code> attribute are those defined
-by <a href="#smil21">[SMIL 2.1]</a>, § 10.4.1,
-while taking into account any overriding semantics defined by this specification.</p></div><div class="div3">
-<h4><a name="timing-attribute-dur" id="timing-attribute-dur"/>10.2.3 dur</h4><p>The <code>dur</code> attribute is used to specify the duration of a
-temporal interval associated with a timed element. If specified,
-the value of a <code>dur</code> attribute must adhere to a
-&lt;timeExpression&gt; specification as defined by <a href="#timing-value-timeExpression"><b>10.3.1 &lt;timeExpression&gt;</b></a>.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>When the <code>clock-time</code> form of a &lt;timeExpression&gt; specification
-is used with a <code>dur</code> attribute, it is intended to be interpreted as
-a difference between two implied clock time expressions.</p></div><p>When a TTML document instance specifies the use of the
-<code>smpte</code> time base and <code>discontinuous</code> marker
-mode, the <code>dur</code> attribute must not be specified on any
-element.</p><p>The semantics of the <code>dur</code> attribute are those defined
-by <a href="#smil21">[SMIL 2.1]</a>, § 10.4.1,
-while taking into account any overriding semantics defined by this specification.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>In the context of the subset of <a href="#smil21">[SMIL 2.1]</a> semantics supported by
-this specification, the active duration of an element that specifies both
-<code>end</code> and <code>dur</code> attributes is equal to the lesser of the value of
-the <code>dur</code> attribute and the difference between the value of the
-<code>end</code> attribute and the element's begin time.</p></div></div><div class="div3">
-<h4><a name="timing-attribute-timeContainer" id="timing-attribute-timeContainer"/>10.2.4 timeContainer</h4><p>The <code>timeContainer</code> attribute is used to specify a local temporal
-context by means of which timed child elements are temporally situated.</p><p>If specified, the value of a <code>timeContainer</code> attribute must be one
-of the following:</p><ul><li><p><code>par</code></p></li><li><p><code>seq</code></p></li></ul><p>If the time container semantics of an element instance is <code>par</code>,
-then the temporal intervals of child elements are considered to apply in
-parallel, i.e., simultaneously in time. Furthermore, the specification of
-the time interval of each child element is considered to be relative to the temporal
-interval of the container element instance.</p><p>If the time container semantics of an element instance is <code>seq</code>,
-then the temporal intervals of child elements are considered to apply in
-sequence, i.e., sequentially in time. Furthermore, the specification of
-the time interval of each child element is considered to be relative to the temporal
-interval of its sibling elements, unless it is the first child element, in which case
-it is considered to be relative to the temporal interval of the container
-element instance.</p><p>Each time container is considered to constitute an independent time base, i.e.,
-time coordinate system.</p><p>If a <code>timeContainer</code> attribute is not specified on an element that
-has time container semantics, then <code>par</code> time container semantics must apply.</p><p>Time container semantics applies only to the following element types:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li></ul><p>The semantics of parallel and sequential time
-containment are those defined by <a href="#smil21">[SMIL 2.1]</a>, § 10.4.2,
-while taking into account any overriding semantics defined by this specification.</p></div></div><div class="div2">
-<h3><a name="timing-time-value-expressions" id="timing-time-value-expressions"/>10.3 Time Value Expressions</h3><p>Timing attribute values include the use of the following expressions:</p><ul><li><p><a href="#timing-value-timeExpression"><b>10.3.1 &lt;timeExpression&gt;</b></a></p></li></ul><div class="div3">
-<h4><a name="timing-value-timeExpression" id="timing-value-timeExpression"/>10.3.1 &lt;timeExpression&gt;</h4><p>A &lt;timeExpression&gt; is used to specify a coordinate along
-some time base, where the applicable time base is determined by the
-<code>ttp:timeBase</code> parameter.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>See <a href="#parameter-attribute-timeBase"><b>6.2.11 ttp:timeBase</b></a>, <a href="#parameter-attribute-frameRate"><b>6.2.4 ttp:frameRate</b></a>, <a href="#parameter-attribute-subFrameRate"><b>6.2.9 ttp:subFrameRate</b></a>, and <a href="#parameter-attribute-tickRate"><b>6.2.10 ttp:tickRate</b></a> for further information on
-explicit specification of time base, frame rate, sub-frame rate, and
-tick rate.</p></div><table summary="HTML Table" id="timeExpression-syntax" class="syntax"><caption>Syntax Representation – &lt;timeExpression&gt;</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : clock-time
-  | offset-time
-
-clock-time
-  : hours ":" minutes ":" seconds ( fraction | ":" frames ( "." sub-frames )? )?
-
-offset-time
-  : time-count fraction? metric
-
-hours
-  : <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>
-  | <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-minutes | seconds
-  : <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>
-
-frames
-  : <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>
-  | <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a> <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-sub-frames
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-fraction
-  : "." <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-time-count
-  : <a href="#style-value-digit">&lt;digit&gt;</a>+
-
-metric
-  : "h"                 // hours
-  | "m"                 // minutes
-  | "s"                 // seconds
-  | "ms"                // milliseconds
-  | "f"                 // frames
-  | "t"                 // ticks
-</pre></div>
-</td></tr></tbody></table><p>If a &lt;timeExpression&gt; is expressed in terms of a
-<em>clock-time</em>, then leading zeroes are used when expressing hours,
-minutes, seconds, and frames less than 10. Minutes are constrained to 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
-<em>clock-time</em> and a <em>frames</em> term is specified,
-then the value of this term must be constrained to the interval
-[0…<em>F-1</em>], where <em>F</em> is the frame rate
-determined by the <code>ttp:frameRate</code> parameter as defined
-by <a href="#parameter-attribute-frameRate"><b>6.2.4 ttp:frameRate</b></a>.</p><p>If a &lt;timeExpression&gt; is expressed in terms of a
-<em>clock-time</em> and a <em>sub-frames</em> term is
-specified, then the value of this term must be constrained to the
-interval [0…<em>S-1</em>], where <em>S</em> is the
-sub-frame rate determined by the <code>ttp:subFrameRate</code> parameter as defined by <a href="#parameter-attribute-subFrameRate"><b>6.2.9 ttp:subFrameRate</b></a>.</p></div></div><div class="div2">
-<h3><a name="timing-time-intervals" id="timing-time-intervals"/>10.4 Time Intervals</h3><p>The semantics of time containment, durations, and intervals defined by
-<a href="#smil21">[SMIL 2.1]</a> apply to the interpretation of like-named timed elements and timing
-vocabulary defined by this specification, given the following
-constraints:</p><ul><li><p>The implicit duration of
-
-an anonymous span
-
-is defined as follows: if
-the
-
-anonymous span's
-
-parent time container is a parallel time container, then
-the implicit duration is equivalent to the <code>indefinite</code>
-duration value as defined by <a href="#smil21">[SMIL 2.1]</a>; if the
-
-anonymous span's
-
-parent time container is a sequential time container, then the
-implicit duration is equivalent to zero.</p></li><li><p>The implicit duration of a <code>body</code>, <code>div</code>, <code>p</code>,
-or <code>span</code> element is determined in accordance to (1) whether
-the element is a parallel or sequential time container, and (2) the
-semantics of <a href="#smil21">[SMIL 2.1]</a> as applied to these time
-containers.</p></li><li><p>The implicit duration of the <code>region</code> element is defined to
-be equivalent to the <code>indefinite</code>
-duration value as defined by <a href="#smil21">[SMIL 2.1]</a>.</p></li><li><p>If the governing time mode is <code>media</code> or
-<code>smpte</code> with mode <code>continuous</code>, then time
-expressions must be interpreted as
-equivalent to offset based timing
-in <a href="#smil21">[SMIL 2.1]</a>, namely, as offsets from an implicit
-syncbase.</p></li><li><p>If the governing time mode is <code>smpte</code> with mode
-<code>discontinuous</code>, then time expressions must be interpreted
-as equivalent to marker values produced by an external marker event
-source, in which case all time expressions are equivalent to event
-based timing in <a href="#smil21">[SMIL 2.1]</a>.</p></li><li><p>If the governing time mode is <code>clock</code>, then time
-expressions must be interpreted as equivalent to wallclock time
-expressions in <a href="#smil21">[SMIL 2.1]</a>, where the applicable wallclock
-used is determined by the clock mode parameter.</p></li></ul></div></div><div class="div1">
-<h2><a name="animation" id="animation"/>11 Animation</h2><p>This section specifies the <em>animation</em> matter of the
-core vocabulary catalog, where
-animation is to be understood as a separable layer of information that combines
-timing and styling in order to denote authorial intention about (temporally) dynamic
-styling of content.</p><div class="div2">
-<h3><a name="animation-element-vocabulary" id="animation-element-vocabulary"/>11.1 Animation Element Vocabulary</h3><p>The following elements specify the structure and principal animation aspects of a
-document instance:</p><ul><li><p><a href="#animation-vocabulary-set"><b>11.1.1 set</b></a></p></li></ul><div class="div3">
-<h4><a name="animation-vocabulary-set" id="animation-vocabulary-set"/>11.1.1 set</h4><p>The <code>set</code> element is used as a child element of a content
-element or a <code>region</code> element
-in order to express a discrete change of some style parameter value
-that applies over some time interval.</p><p>The <code>set</code> element accepts as its children zero or more
-elements in the <code>Metadata.class</code> element group.</p><table summary="HTML Table" id="elt-syntax-set" class="syntax"><caption>XML Representation – Element Information Item: set</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;set
-  <a href="#timing-attribute-begin">begin</a> = <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a>
-  <a href="#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="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>a single 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-table">Metadata.class</a>*
-&lt;/set&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The use of multiple <code>set</code> element children may be used to effect fade and
-position transitions.</p></div><p>An example of using the <code>set</code> element to animate content
-styling is illustrated below:</p><table summary="HTML Table" id="animation-vocabulary-set-example-1" class="example"><caption>Example Fragment – Content Style Animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;p dur="5s" tts:color="yellow"&gt;
-<span class="strong">&lt;set begin="1s" dur="1s" tts:color="red"/&gt;</span>
-<span class="strong">&lt;set begin="2s" dur="1s" tts:color="green"/&gt;</span>
-<span class="strong">&lt;set begin="3s" dur="1s" tts:color="red"/&gt;</span>
-Text with Flashing Colors!
-&lt;/p&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the foreground color of the content "Text
-with Flashing Colors" is animated from yellow, to red, to green, to
-red, then back to yellow over a 5 second period.</p></div><p>An example of using the <code>set</code> element to animate region
-styling is illustrated below:</p><table summary="HTML Table" id="animation-vocabulary-set-example-2" class="example"><caption>Example Fragment – Region Style Animation</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;tt xml:lang="" xmlns="http://www.w3.org/ns/ttml"
-    xmlns:ttp="http://www.w3.org/ns/ttml#parameter"
-    xmlns:tts="http://www.w3.org/ns/ttml#styling"
-    ttp:cellResolution="40 16"&gt;
-    &lt;head&gt;
-      &lt;layout&gt;
-	&lt;region xml:id="r1" timeContainer="seq"&gt;
-	  <span class="strong">&lt;set dur="10s" tts:origin=" 8c 14c"/&gt;</span>
-	  <span class="strong">&lt;set dur="2s"  tts:origin=" 2c  2c"/&gt;</span>
-	  <span class="strong">&lt;set dur="3s"  tts:origin=" 8c 14c"/&gt;</span>
-	  <span class="strong">&lt;set dur="2s"  tts:origin="14c  4c"/&gt;</span>
-	  <span class="strong">&lt;set dur="10s" tts:origin=" 8c 14c"/&gt;</span>
-	  &lt;style tts:extent="24c 2c"/&gt;
-	&lt;/region&gt;
-      &lt;/layout&gt;
-    &lt;/head&gt;
-    &lt;body region="r1"&gt;...&lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, the root container region is divided into a
-cell grid of 40 columns and 16 rows. A region, <code>r1</code>, with
-dimensions of 24 columns and 2 rows is then positioned within the
-root container region, with its position varying over time in order to
-create an effect of moving the region, which may be desirable so as
-to avoid obscuring characters in an underlying video with captions.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>The semantics of the <code>set</code> element
-are based upon that defined by <a href="#smil21">[SMIL 2.1]</a>,
-§ 3.6.2.</p></div></div></div><div class="div2">
-<h3><a name="animation-attribute-vocabulary" id="animation-attribute-vocabulary"/>11.2 Animation Attribute Vocabulary</h3><p>No animation related attribute vocabulary is defined for use in the
-core vocabulary catalog.</p></div></div><div class="div1">
-<h2><a name="metadata" id="metadata"/>12 Metadata</h2><p>This section specifies the <em>metadata</em> matter of the core
-vocabulary catalog, where
-metadata is to be understood as a separable layer of information that applies to
-parameters, content,
-style, layout, timing, and even metadata itself, where the information
-represented by metadata takes one of two forms: (1) metadata defined by this
-specification for standardized use in a document instance, and (2) arbitrary
-metadata defined outside of the scope of this specification, whose use and
-semantics depend entirely upon an application's use of TTML content.</p><div class="div2">
-<h3><a name="metadata-element-vocabulary" id="metadata-element-vocabulary"/>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
-used in a document instances:
-</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 name="metadata-vocabulary-metadata" id="metadata-vocabulary-metadata"/>12.1.1 metadata</h4><p>The <code>metadata</code> element functions as a generic container for metadata
-information.</p><p>Metadata information may be expressed by a <code>metadata</code> element
-in one of two (non-mutually exclusive) manners: (1) by specifying one
-or more metadata attributes on the <code>metadata</code>
-element, and (2) by specifying one
-or more child elements
-in the <code>metadata</code> element
-that express metadata. Both types of metadata
-are referred to in this document as <em>metadata items</em>.</p><table summary="HTML Table" id="elt-syntax-metadata" class="syntax"><caption>XML Representation – Element Information Item: metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;metadata
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute in TT Metadata namespace</em>}
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> ({<em>any element in TT Metadata namespace</em>}|{<em>any element not in any TT namespace</em>})*
-&lt;/metadata&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>The meaning of a specific metadata item must be evaluated in the
-context of where it appears. The core vocabulary catalog permits an
-arbitrary number of <code>metadata</code> element children of any
-content element type except for the
-<code>tt</code> element. See specific element
-vocabulary definitions for any constraints that apply to such
-usage.</p></div><p>The use of document metadata is illustrated by the following example.</p><table summary="HTML Table" id="metadata-vocabulary-metadata-example-1" class="example"><caption>Example Fragment – Document Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;head&gt;
-  &lt;metadata xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-    &lt;ttm:title&gt;Document Metadata Example&lt;/ttm:title&gt;
-    &lt;ttm:desc&gt;This document employs document metadata.&lt;/ttm:desc&gt;
-  &lt;/metadata&gt;
-&lt;/head&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p/><p>The use of element metadata is illustrated by the following example.</p><table summary="HTML Table" id="metadata-vocabulary-metadata-example-2" class="example"><caption>Example Fragment – Element Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;div&gt;
-  &lt;metadata xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-    &lt;ttm:title&gt;Chapter 6 – Sherlock Holmes Gives a Demonstration&lt;/ttm:title&gt;
-    &lt;ttm:desc&gt;Holmes shows Watson how the murderer entered the window.&lt;/ttm:desc&gt;
-  &lt;/metadata&gt;
-&lt;/div&gt;
-...
-</pre></div>
-</td></tr></tbody></table><p/><p>The use of metadata attribute items is illustrated by the following example.</p><table summary="HTML Table" id="metadata-vocabulary-metadata-example-3" class="example"><caption>Example Fragment – Foreign Metadata Attribute Items</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;div xmlns:ext="http://foo.bar.example.org/ttaf1#metadata"&gt;
-  &lt;metadata ext:ednote="remove this division prior to publishing"/&gt;
-&lt;/div&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a global attribute from a foreign (external)
-namespace is used to express a metadata attribute that applies
-semantically to the containing <code>div</code> element. Note that the
-attribute may also be expressed directly on the <code>div</code> element;
-however, in this case the author wishes to segregate certain metadata
-attributes by expressing them indirectly on <code>metadata</code>
-elements.</p></div><p/><p>The use of foreign element metadata is illustrated by the following example.</p><table summary="HTML Table" id="metadata-vocabulary-metadata-example-4" class="example"><caption>Example Fragment – Foreign Element Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-...
-&lt;metadata
-  xmlns:dc="http://purl.org/dc/elements/1.1/"
-  xmlns:dcterms="http://purl.org/dc/terms/"
-  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
-  &lt;dc:title&gt;Foreign Element Metadata Example&lt;/dc:title&gt;
-  &lt;dc:description&gt;Express metadata using elements in foreign namespace.&lt;/dc:description&gt;
-  &lt;dc:format xsi:type="dcterms:IMT"&gt;application/ttml+xml&lt;/dc:format&gt;
-&lt;/metadata&gt;
-...
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, a number of elements defined by the Dublin
-Core metadata vocabulary are used to express document level metadata.</p></div><p/></div><div class="div3">
-<h4><a name="metadata-vocabulary-title" id="metadata-vocabulary-title"/>12.1.2 ttm:title</h4><p>The <code>ttm:title</code> element is used to express a human-readable title of
-a specific element instance.</p><table summary="HTML Table" id="elt-syntax-metadata-title" class="syntax"><caption>XML Representation – Element Information Item: ttm:title</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:title
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:title&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>No specific use of the <code>ttm:title</code> element is defined by this specification.</p></div><p>Examples of the <code>ttm:title</code> element are shown above in
-<a href="#metadata-vocabulary-metadata-example-1"><b>Example Fragment – Document Metadata</b></a> and
-<a href="#metadata-vocabulary-metadata-example-2"><b>Example Fragment – Element Metadata</b></a>.</p></div><div class="div3">
-<h4><a name="metadata-vocabulary-desc" id="metadata-vocabulary-desc"/>12.1.3 ttm:desc</h4><p>The <code>ttm:desc</code> element is used to express a human-readable description of
-a specific element instance.</p><table summary="HTML Table" id="elt-syntax-metadata-desc" class="syntax"><caption>XML Representation – Element Information Item: ttm:desc</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:desc
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:desc&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>No specific use of the <code>ttm:desc</code> element is defined by this specification.</p></div><p>Examples of the <code>ttm:desc</code> element are shown above in
-<a href="#metadata-vocabulary-metadata-example-1"><b>Example Fragment – Document Metadata</b></a> and
-<a href="#metadata-vocabulary-metadata-example-2"><b>Example Fragment – Element Metadata</b></a>.</p></div><div class="div3">
-<h4><a name="metadata-vocabulary-copyright" id="metadata-vocabulary-copyright"/>12.1.4 ttm:copyright</h4><p>The <code>ttm:copyright</code> element is used to express a human-readable copyright that
-applies to some scoping level.</p><p>A copyright statement that applies to a document as a whole should appear as a
-child of the <code>head</code> element.</p><table summary="HTML Table" id="elt-syntax-metadata-copyright" class="syntax"><caption>XML Representation – Element Information Item: ttm:copyright</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:copyright
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:copyright&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>No specific use of the <code>ttm:copyright</code> element is defined by this specification.</p></div></div><div class="div3">
-<h4><a name="metadata-vocabulary-agent" id="metadata-vocabulary-agent"/>12.1.5 ttm:agent</h4><p>The <code>ttm:agent</code> element is used to define an agent for the purpose of associating
-content information with an agent who is involved in the production or expression of that content.</p><p>The <code>ttm:agent</code> element accepts as its children zero or more <code>ttm:name</code> elements followed by
-zero or one <code>ttm:actor</code> element.</p><p>At least one <code>ttm:name</code> element child should be specified that expresses a name for the
-agent, whether it be the name of a person, character, group, or organization.</p><table summary="HTML Table" id="elt-syntax-metadata-agent" class="syntax"><caption>XML Representation – Element Information Item: ttm:agent</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:agent
-  <span class="reqattr">type</span> = (<em>person</em>|<em>character</em>|<em>group</em>|<em>organization</em>|<em>other</em>)
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> <a href="#metadata-vocabulary-name">ttm:name</a>*, <a href="#metadata-vocabulary-actor">ttm:actor</a>?
-&lt;/ttm:agent&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>type</code> attribute must be specified on each <code>ttm:agent</code> element, and,
-if specified, must have one of the following values:</p><ul><li><p><code>person</code></p></li><li><p><code>character</code></p></li><li><p><code>group</code></p></li><li><p><code>organization</code></p></li><li><p><code>other</code></p></li></ul><p>If the value of the <code>type</code> attribute is <code>character</code>, then the
-<code>ttm:agent</code> element instance should specify a <code>ttm:actor</code> child that
-specifies the agent that plays the role of the actor.</p><p>A <code>ttm:agent</code> metadata item is considered to be significant only
-when specified as a child of the <code>head</code> element or as a child of a
-<code>metadata</code> element child of the <code>head</code> element.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A <code>ttm:agent</code> element instance is typically referenced using a <code>ttm:agent</code>
-attribute on a content element.</p></div><div class="note"><p class="prefix"><b>Note:</b></p><p>If a character agent is played by multiple actors, then multiple character
-agents may be specified (and referenced) wherein different definitions of the
-character specify different actors.</p></div><p>The use of agent metadata is illustrated by the following example.</p><table summary="HTML Table" id="metadata-vocabulary-agent-example-1" class="example"><caption>Example Fragment – Agent Metadata</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-
-&lt;tt xml:lang="en" xmlns="http://www.w3.org/ns/ttml" xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-  &lt;head&gt;
-    <span class="strong">&lt;ttm:agent xml:id="connery" type="person"&gt;</span>
-      &lt;ttm:name type="family"&gt;Connery&lt;/ttm:name&gt;
-      &lt;ttm:name type="given"&gt;Thomas Sean&lt;/ttm:name&gt;
-      &lt;ttm:name type="alias"&gt;Sean&lt;/ttm:name&gt;
-      &lt;ttm:name type="full"&gt;Sir Thomas Sean Connery&lt;/ttm:name&gt;
-    <span class="strong">&lt;/ttm:agent&gt;</span>
-    <span class="strong">&lt;ttm:agent xml:id="bond" type="character"&gt;</span>
-      &lt;ttm:name type="family"&gt;Bond&lt;/ttm:name&gt;
-      &lt;ttm:name type="given"&gt;James&lt;/ttm:name&gt;
-      &lt;ttm:name type="alias"&gt;007&lt;/ttm:name&gt;
-      &lt;ttm:actor agent="connery"/&gt;
-    <span class="strong">&lt;/ttm:agent&gt;</span>
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;div&gt;
-      ...  
-      &lt;p <span class="strong">ttm:agent="bond"</span>&gt;I travel, a sort of licensed troubleshooter.&lt;/p&gt;
-      ...  
-    &lt;/div&gt;
-  &lt;/body&gt;
-&lt;/tt&gt;
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>In the above example, two agents, a real (person) agent, Sean
-Connery, and a fictitious (character) agent, James Bond, are defined,
-where the latter is linked to the former by means of the a
-<code>ttm:actor</code> element. A reference is then made from content (the
-<code>p</code> element) to the character agent associated with
-(responsible for producing) that content. Note that in this example
-the <code>ttm:agent</code> metadata items are specified as immediate
-children of the document's <code>head</code> element rather than being
-placed in a container <code>metadata</code> element.</p></div></div><div class="div3">
-<h4><a name="metadata-vocabulary-name" id="metadata-vocabulary-name"/>12.1.6 ttm:name</h4><p>The <code>ttm:name</code> element is used to specify a name of a person, character,
-group, or organization.</p><table summary="HTML Table" id="elt-syntax-metadata-name" class="syntax"><caption>XML Representation – Element Information Item: ttm:name</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:name
-  <span class="reqattr">type</span> = (<em>full</em>|<em>family</em>|<em>given</em>|<em>alias</em>|<em>other</em>)
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> #PCDATA
-&lt;/ttm:name&gt;
-</pre></div>
-</td></tr></tbody></table><p>A <code>type</code> attribute must be specified on each <code>ttm:name</code> element, and,
-if specified, must have one of the following values:</p><ul><li><p><code>full</code></p></li><li><p><code>family</code></p></li><li><p><code>given</code></p></li><li><p><code>alias</code></p></li><li><p><code>other</code></p></li></ul><p>The relationship between the type of a name and the syntactic expression of the name
-is not defined by this specification.</p><p>Two examples of the <code>ttm:name</code> element are shown above in
-<a href="#metadata-vocabulary-agent-example-1"><b>Example Fragment – Agent Metadata</b></a>.</p></div><div class="div3">
-<h4><a name="metadata-vocabulary-actor" id="metadata-vocabulary-actor"/>12.1.7 ttm:actor</h4><p>The <code>ttm:actor</code> element is used to link the definition of a (role-based) character
-agent with another agent that portrays the character.</p><table summary="HTML Table" id="elt-syntax-metadata-actor" class="syntax"><caption>XML Representation – Element Information Item: ttm:actor</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-&lt;ttm:actor
-  <span class="reqattr">agent</span> = IDREF
-  <a href="#content-attribute-id">xml:id</a> = ID
-  <a href="#content-attribute-lang">xml:lang</a> = string
-  <a href="#content-attribute-space">xml:space</a> = (<em>default</em>|<em>preserve</em>)
-  {<em>any attribute not in default or any TT namespace</em>}&gt;
-  <em>Content:</em> EMPTY
-&lt;/ttm:actor&gt;
-</pre></div>
-</td></tr></tbody></table><p>The <code>agent</code> attribute of a <code>ttm:actor</code> element must
-reference a <code>ttm:agent</code> element that denotes the person,
-group, or organization acting the part of a character.</p><p>An example of the <code>ttm:actor</code> element is shown above in
-<a href="#metadata-vocabulary-agent-example-1"><b>Example Fragment – Agent Metadata</b></a>.</p></div></div><div class="div2">
-<h3><a name="metadata-attribute-vocabulary" id="metadata-attribute-vocabulary"/>12.2 Metadata Attribute Vocabulary</h3><p>This section specifies the following attributes in the TT Metadata Namespace
-for use with the <code>metadata</code> element and with certain content elements:</p><ul><li><p><a href="#metadata-attribute-agent"><b>12.2.1 ttm:agent</b></a></p></li><li><p><a href="#metadata-attribute-role"><b>12.2.2 ttm:role</b></a></p></li></ul><div class="note"><p class="prefix"><b>Note:</b></p><p>Only certain metadata item attributes may be used with content elements. See
-the definitions of content elements to determine permissible usage.</p></div><div class="div3">
-<h4><a name="metadata-attribute-agent" id="metadata-attribute-agent"/>12.2.1 ttm:agent</h4><p>The <code>ttm:agent</code> attribute takes an <code>IDREFS</code>
-value, and is used with certain content elements to designate the
-agents that perform or are
-involved in the performance of the content.</p><p>If specified, a <code>ttm:agent</code> attribute must reference
-<code>ttm:agent</code> element instances that appear
-as a descendent of the same document instance as
-that of the referring element.</p><p>An example of the <code>ttm:agent</code> attribute is shown above in
-<a href="#metadata-vocabulary-agent-example-1"><b>Example Fragment – Agent Metadata</b></a>.</p></div><div class="div3">
-<h4><a name="metadata-attribute-role" id="metadata-attribute-role"/>12.2.2 ttm:role</h4><p>The <code>ttm:role</code> attribute may be used by a content author
-to express
-the roles, functions, or characteristics
-of some content element that is so labeled.</p><p>If specified, the value of this attribute must adhere to the following
-syntax, where
-the syntactic element <em>S</em> must adhere to production
-[3] <code>S</code> as defined by <a href="#xml10">[XML 1.0]</a> §
-2.3:</p><table summary="HTML Table" id="metadata-attribute-role-syntax" class="syntax"><caption>Syntax Representation – ttm:role</caption><tbody><tr><td>
-<div class="exampleInner"><pre>
-ttm:role
-  role ( <em>S</em> role )*
-
-role
-  : "action"
-  | "caption"
-  | "description"
-  | "dialog"
-  | "expletive"
-  | "kinesic"
-  | "lyrics"
-  | "music"
-  | "narration"
-  | "quality"
-  | "sound"
-  | "source"
-  | "suppressed"
-  | "reproduction"
-  | "thought"
-  | "title"
-  | "transcription"
-  | extension-role
-
-extension-role
-  : "x-" token-char+
-
-token-char
-  : { XML NameChar }    // XML 1.1 Production [4a]
-</pre></div>
-</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>All values of <code>ttm:role</code> that do not start with the prefix
-<code>x-</code> are reserved for future standardization.</p></div></div></div></div></div><div class="back"><div class="div1">
-<h2><a name="reduced-infoset" id="reduced-infoset"/>A Reduced XML Infoset</h2><p><em>This appendix is normative.</em></p><p>For the purposes of this specification, a Reduced XML Infoset is
-an XML Information Set <a href="#infoset">[XML InfoSet]</a> that consists of only the following information items
-and information item properties:</p><div class="div2">
-<h3><a name="reduced-infoset-document" id="reduced-infoset-document"/>A.1 Document Information Item</h3><ul><li><p><code>[document element]</code></p></li></ul></div><div class="div2">
-<h3><a name="reduced-infoset-element" id="reduced-infoset-element"/>A.2 Element Information Item</h3><ul><li><p><code>[namespace URI]</code></p></li><li><p><code>[local name]</code></p></li><li><p><code>[children]</code></p></li><li><p><code>[attributes]</code></p></li></ul><p>Child information items <code>[children]</code> are reduced to 
-only element and character information items.</p></div><div class="div2">
-<h3><a name="reduced-infoset-attribute" id="reduced-infoset-attribute"/>A.3 Attribute Information Item</h3><ul><li><p><code>[namespace URI]</code></p></li><li><p><code>[local name]</code></p></li><li><p><code>[normalized value]</code></p></li></ul></div><div class="div2">
-<h3><a name="reduced-infoset-character" id="reduced-infoset-character"/>A.4 Character Information Item</h3><ul><li><p><code>[character code]</code></p></li></ul><p>Contiguous character information items are not required to be represented distinctly,
-but may be aggregated (chunked) into a sequence of character codes (i.e., a character string).</p></div></div><div class="div1">
-<h2><a name="schemas" id="schemas"/>B Schemas</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the following schemas for use with
-DFXP Content document instances:</p><ul><li><p>Relax NG, Compact Syntax (RNC) Schema</p></li><li><p>XML Schema Definition (XSD) Schema</p></li></ul><p>In any case where a schema specified by this appendix differs from the
-normative definitions of document type, element type, or attribute type
-as defined by the body of this specification, then the body of this
-specification takes precedence.</p><div class="div2">
-<h3><a name="dfxp-schema-rnc" id="dfxp-schema-rnc"/>B.1 Relax NG Schema</h3><p>This section specifies a Relax NG Compact Syntax (RNC) <a href="#rng">[RELAX NG]</a> based schema
-for DFXP Content, also available in a <a href="rnc/schema.zip">ZIP
-Archive</a>.</p><div class="div3">
-<h4><a name="rnc-dfxp-driver-schema" id="rnc-dfxp-driver-schema"/>B.1.1 Driver</h4><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 Distribution Format Exchange Profile (DFXP) Schema ..........
-# .......................................................................
-
-# default namespace
-default namespace tt = "http://www.w3.org/ns/ttml"
-
-# generic tt modules
-include "ttaf1-dfxp-datatypes.rnc"
-include "ttaf1-dfxp-classes.rnc"
-include "ttaf1-dfxp-core-attribs.rnc"
-include "ttaf1-dfxp-parameter-attribs.rnc"
-include "ttaf1-dfxp-metadata-attribs.rnc"
-include "ttaf1-dfxp-styling-attribs.rnc"
-include "ttaf1-dfxp-timing-attribs.rnc"
-include "ttaf1-dfxp-parameter-items.rnc"
-include "ttaf1-dfxp-parameters.rnc"
-include "ttaf1-dfxp-metadata-items.rnc"
-include "ttaf1-dfxp-metadata.rnc"
-include "ttaf1-dfxp-styling.rnc"
-include "ttaf1-dfxp-animation.rnc"
-include "ttaf1-dfxp-layout.rnc"
-include "ttaf1-dfxp-content.rnc"
-include "ttaf1-dfxp-head.rnc"
-include "ttaf1-dfxp-document.rnc"
-
-start = TTAF.tt | TTAF.parameters.profile
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div3">
-<h4><a name="rnc-dfxp-modules" id="rnc-dfxp-modules"/>B.1.2 Modules</h4><div class="div4">
-<h5><a name="rnc-dfxp-animation-module" id="rnc-dfxp-animation-module"/>B.1.2.1 Animation Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Animation Module .......................................
-# .......................................................................
-
-# set - discrete animation
-TTAF.set =
-  element set {
-    TTAF.set.attlist,
-    TTAF.set.content
-  }
-
-TTAF.set.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.Timed.attrib.class,
-  (TTAF.Styling.attrib.class |
-   TTAF.Styling.ForeignExtension.attrib+ )
-
-TTAF.set.content.extra = empty
-TTAF.set.content =
-  (TTAF.Metadata.class*,
-   TTAF.set.content.extra*)
-
-TTAF.Animation.extra = empty
-TTAF.Animation.class |=
-  TTAF.set |
-  TTAF.Animation.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-classes-module" id="rnc-dfxp-classes-module"/>B.1.2.2 Classes Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Class Declarations Module ..............................
-# .......................................................................
-
-# attribute group classes
-TTAF.Core.attrib.class = empty
-TTAF.Metadata.attrib.class = empty
-TTAF.Parameter.attrib.class = empty
-TTAF.RegionBinding.attrib.class = empty
-TTAF.StyleBinding.attrib.class = empty
-TTAF.Styled.attrib.class = empty
-TTAF.Styling.attrib.class = empty
-TTAF.Timed.attrib.class = empty
-TTAF.TimedContainer.attrib.class = empty
-TTAF.TimingInterval.attrib.class = empty
-
-# element group classes
-TTAF.Animation.class = empty
-TTAF.Block.class = empty
-TTAF.BlockNoDiv.class = empty
-TTAF.Inline.class = empty
-TTAF.InlineNoSpan.class = empty
-TTAF.MetadataNoAgent.class = empty
-TTAF.Metadata.class = empty
-TTAF.MetadataItems.class = empty
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-content-module" id="rnc-dfxp-content-module"/>B.1.2.3 Content Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Content Module .........................................
-# .......................................................................
-
-# body - content body
-TTAF.body =
-  element body {
-    TTAF.body.attlist,
-    TTAF.body.content
-  }
-
-TTAF.body.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.body.content.extra = empty
-TTAF.body.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Block.class | TTAF.body.content.extra)*)
-
-# div - division
-TTAF.div =
-  element div {
-    TTAF.div.attlist,
-    TTAF.div.content
-  }
-
-TTAF.div.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.div.content.extra = empty
-TTAF.div.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Block.class | TTAF.div.content.extra)*)
-
-# p - paragraph
-TTAF.p =
-  element p {
-    TTAF.p.attlist,
-    TTAF.p.content
-  }
-
-TTAF.p.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.p.content.extra = empty
-TTAF.p.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Inline.class |
-    TTAF.p.content.extra)*)
-
-# span - intra-paragraph inline span
-TTAF.span =
-  element span {
-    TTAF.span.attlist,
-    TTAF.span.content
-  }
-
-TTAF.span.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.RegionBinding.attrib.class,
-  TTAF.Styled.attrib.class,
-  TTAF.TimedContainer.attrib.class
-
-TTAF.span.content.extra = empty
-TTAF.span.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   (TTAF.Inline.class |
-    TTAF.span.content.extra)*)
-
-# br - manual line break
-TTAF.br =
-  element br {
-    TTAF.br.attlist,
-    TTAF.br.content
-  }
-
-TTAF.br.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.Metadata.attrib.class,
-  TTAF.Styled.attrib.class
-
-TTAF.br.content.extra = empty
-TTAF.br.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   TTAF.br.content.extra*)
-
-# Block.class
-TTAF.Block.extra = empty
-TTAF.BlockNoDiv.class |=
-  TTAF.p | TTAF.Block.extra
-TTAF.Block.class |=
-  TTAF.div | TTAF.BlockNoDiv.class
-
-# Inline.class
-TTAF.Inline.extra = empty
-TTAF.InlineNoSpan.class |=
-  text | TTAF.br | TTAF.Inline.extra
-TTAF.Inline.class |=
-  TTAF.span | TTAF.InlineNoSpan.class
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-core-attribs-module" id="rnc-dfxp-core-attribs-module"/>B.1.2.4 Core Attributes Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Core Attributes Module .................................
-# .......................................................................
-
-TTAF.id.attrib
-  = attribute xml:id { xsd:ID }?
-
-TTAF.lang.attrib
-  = attribute xml:lang { TTAF.LanguageCode.datatype }?
-
-TTAF.lang.required.attrib
-  = attribute xml:lang { TTAF.LanguageCode.datatype }
-
-TTAF.space.attrib
-  = attribute xml:space { TTAF.XMLSpace.datatype }?
-
-TTAF.Core.extra.attrib
-  = empty
-
-TTAF.Core.attrib.class &amp;=
-  TTAF.id.attrib,
-  TTAF.lang.attrib,
-  TTAF.space.attrib,
-  TTAF.Core.extra.attrib
-
-TTAF.Core.required.attrib.class &amp;=
-  TTAF.id.attrib,
-  TTAF.lang.required.attrib,
-  TTAF.space.attrib,
-  TTAF.Core.extra.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-datatypes-module" id="rnc-dfxp-datatypes-module"/>B.1.2.5 Data Types Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Datatypes Module .......................................
-# .......................................................................
-
-TTAF.Alpha.datatype =
-  xsd:float { minInclusive = "0" maxInclusive = "1" }
-
-TTAF.Agent.datatype =
-  xsd:IDREFS
-
-TTAF.CellResolution.datatype =
-  string
-
-TTAF.ClockMode.datatype =
-  "local" |
-  "gps" |
-  "utc"
-
-TTAF.Color.datatype =
-  string
-
-TTAF.Direction.datatype =
-  "ltr" |
-  "rtl"
-
-TTAF.Display.datatype =
-  "auto" |
-  "none"
-
-TTAF.DisplayAlign.datatype =
-  "before" |
-  "center" |
-  "after"
-
-TTAF.DropMode.datatype =
-  "dropNTSC" |
-  "dropPAL" |
-  "nonDrop"
-
-TTAF.ExtensionDesignator.datatype =
-  TTAF.URI.datatype
-
-TTAF.ExtensionValue.datatype =
- "optional" |
- "required" |
- "use"
-
-TTAF.Extent.datatype =
-  string
-
-TTAF.FeatureDesignator.datatype =
-  TTAF.URI.datatype
-
-TTAF.FeatureValue.datatype =
- "optional" |
- "required" |
- "use"
-
-TTAF.FontFamily.datatype =
-  string
-
-TTAF.FontSize.datatype =
-  string
-
-TTAF.FontStyle.datatype =
-  "normal" |
-  "italic" |
-  "oblique"
-
-TTAF.FontWeight.datatype =
-  "normal" |
-  "bold"
-
-TTAF.FrameRate.datatype =
-  xsd:nonNegativeInteger
-
-TTAF.FrameRateMultiplier.datatype =
-  xsd:string { pattern = "\p{Nd}+\s+\p{Nd}+" }
-
-TTAF.LanguageCode.datatype =
-  xsd:NMTOKEN
-
-TTAF.LineHeight.datatype =
-  string
-
-TTAF.MarkerMode.datatype =
-  "continuous" |
-  "discontinuous"
-
-TTAF.MetadataAgentType.datatype =
-  "person" |
-  "character" |
-  "group" |
-  "organization" |
-  "other"
-
-TTAF.MetadataNameType.datatype =
-  "full" |
-  "family" |
-  "given" |
-  "alias" |
-  "other"
-
-TTAF.MetadataRoleBaseType.datatype =
-  "action" |
-  "caption" |
-  "description" |
-  "dialog" |
-  "expletive" |
-  "kinesic" |
-  "lyrics" |
-  "music" |
-  "narration" |
-  "quality" |
-  "sound" |
-  "source" |
-  "suppressed" |
-  "reproduction" |
-  "thought" |
-  "title" |
-  "transcription"
-
-TTAF.Opacity.datatype =
-  string
-
-TTAF.Origin.datatype =
-  string
-
-TTAF.Overflow.datatype =
-  "visible" |
-  "hidden" 
-
-TTAF.Padding.datatype =
-  string
-
-TTAF.PixelAspectRatio.datatype =
-  xsd:string { pattern = "\p{Nd}+\s+\p{Nd}+" }
-
-TTAF.Profile.datatype =
-  TTAF.URI.datatype
-
-TTAF.Role.datatype =
-  xsd:NMTOKENS
-
-TTAF.ShowBackground.datatype =
-  "always" |
-  "whenActive"
-
-TTAF.SubFrameRate.datatype =
-  xsd:positiveInteger
-
-TTAF.TextAlign.datatype =
-  "left" |
-  "center" |
-  "right" |
-  "start" |
-  "end"
-
-TTAF.TextDecoration.datatype =
-  "none" |
-  "underline" |
-  "noUnderline" |
-  "overline" |
-  "noOverline" |
-  "lineThrough" |
-  "noLineThrough"
-
-TTAF.TextOutline.datatype =
-  string
-
-TTAF.TickRate.datatype =
-  xsd:positiveInteger
-
-TTAF.TimeBase.datatype =
-  "media" |
-  "smpte" |
-  "clock"
-
-TTAF.TimeContainer.datatype =
-  "par" |
-  "seq"
-
-TTAF.TimeCoordinate.datatype =
-  string
-
-TTAF.TimeDuration.datatype =
-  string
-
-TTAF.URI.datatype =
-  xsd:anyURI
-
-TTAF.UnicodeBidi.datatype =
-  "normal" |
-  "embed" |
-  "bidiOverride"
-
-TTAF.Visibility.datatype =
-  "hidden" |
-  "visible"
-
-TTAF.WrapOption.datatype =
-  "wrap" |
-  "noWrap"
-
-TTAF.WritingMode.datatype =
-  "lrtb" |
-  "rltb" |
-  "tbrl" |
-  "tblr" |
-  "lr" |
-  "rl" |
-  "tb"
-
-TTAF.XMLSpace.datatype =
-  "default" |
-  "preserve"
-
-TTAF.ZIndex.datatype =
-  string
-  
-# .......................................................................
-# .......................................................................
-# .......................................................................
-
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-document-module" id="rnc-dfxp-document-module"/>B.1.2.6 Document Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Document Module ........................................
-# .......................................................................
-
-## tt - generic top-level document element type
-TTAF.tt =
-  element tt {
-    TTAF.tt.attlist,
-    TTAF.tt.content
-  }
-
-TTAF.tt.attlist &amp;=
-  TTAF.Core.required.attrib.class,
-  TTAF.Parameter.attrib.class,
-  TTAF.extent.attrib
-
-TTAF.tt.content =
-  (TTAF.head?, TTAF.body?)
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-head-module" id="rnc-dfxp-head-module"/>B.1.2.7 Header Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Header Module ..........................................
-# .......................................................................
-
-# head - generic header
-TTAF.head =
-  element head {
-    TTAF.head.attlist,
-    TTAF.head.content
-  }
-
-TTAF.head.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.head.content.extra = empty
-TTAF.head.content =
-  (TTAF.Metadata.class*,
-   TTAF.Parameters.class*,
-   TTAF.styling?,
-   TTAF.layout?,
-   TTAF.head.content.extra*)
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-layout-module" id="rnc-dfxp-layout-module"/>B.1.2.8 Layout Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Layout Module ..........................................
-# .......................................................................
-
-# region reference attribute; must reference /head/layout/region
-TTAF.region.attrib
-  = attribute region { xsd:IDREF }?
-
-# region binding attribute class
-TTAF.RegionBinding.attrib.class &amp;=
-  TTAF.region.attrib
-
-# layout - generic layout container
-TTAF.layout =
-  element layout {
-    TTAF.layout.attlist,
-    TTAF.layout.content
-  }
-
-TTAF.layout.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.layout.content.extra = empty
-TTAF.layout.content =
-  (TTAF.Metadata.class*,
-   TTAF.layout.region*,
-   TTAF.layout.content.extra*)
-
-# region - region declaration
-TTAF.layout.region =
-  element region {
-    TTAF.layout.region.attlist,
-    TTAF.layout.region.content
-  }
-
-TTAF.layout.region.attlist &amp;=
-  TTAF.Core.attrib.class,
-  TTAF.TimedContainer.attrib.class,
-  TTAF.style.attrib,
-  (TTAF.Styling.attrib.class |
-   TTAF.Styling.ForeignExtension.attrib+ )
-
-TTAF.layout.region.content.extra = empty
-TTAF.layout.region.content =
-  (TTAF.Metadata.class*,
-   TTAF.Animation.class*,
-   TTAF.styling.style*,
-   TTAF.layout.region.content.extra*)
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-metadata-module" id="rnc-dfxp-metadata-module"/>B.1.2.9 Metadata Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Metadata Module ........................................
-# .......................................................................
-
-# namespace prefix bindings
-namespace tt = "http://www.w3.org/ns/ttml"
-namespace ttm = "http://www.w3.org/ns/ttml#metadata"
-namespace local = ""
-
-# meta - generic metadata
-TTAF.metadata =
-  element metadata {
-    TTAF.metadata.attlist,
-    TTAF.metadata.content
-  }
-
-TTAF.metadata.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.External.class =
-  element * - ( tt:* | ttm:* ) {
-    ( attribute * - ( xml:id ) { text }
-      | text
-      | TTAF.External.class
-    )*
-  }
-
-TTAF.metadata.content.extra = empty
-TTAF.metadata.content =
-  (TTAF.MetadataItems.class |
-   TTAF.External.class |
-   TTAF.metadata.content.extra)*
-
-TTAF.Metadata.class |=
-  TTAF.MetadataItems.class |
-  TTAF.metadata
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-metadata-items-module" id="rnc-dfxp-metadata-items-module"/>B.1.2.10 Metadata Items Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Metadata Items Module ......................................
-# .......................................................................
-
-namespace ttm = "http://www.w3.org/ns/ttml#metadata"
-
-## actor - specifies actor
-TTAF.meta.actor =
-  element ttm:actor {
-    TTAF.meta.actor.attlist,
-    TTAF.meta.actor.content
-  }
-
-TTAF.meta.actor.attlist &amp;=
-  TTAF.Core.attrib.class,
-  attribute agent { xsd:IDREF }
-
-TTAF.meta.actor.content.extra = empty
-TTAF.meta.actor.content = empty
-
-## agent - specifies agent
-TTAF.meta.agent =
-  element ttm:agent {
-    TTAF.meta.agent.attlist,
-    TTAF.meta.agent.content
-  }
-
-TTAF.meta.agent.attlist &amp;=
-  TTAF.Core.attrib.class,
-  attribute type { TTAF.MetadataAgentType.datatype }
-
-TTAF.meta.agent.content.extra = empty
-TTAF.meta.agent.content =
-  (TTAF.meta.name*,
-   TTAF.meta.actor?,
-   TTAF.meta.agent.content.extra*)
-
-## copyright - specifies copyright statement
-TTAF.meta.copyright =
-  element ttm:copyright {
-    TTAF.meta.copyright.attlist,
-    TTAF.meta.copyright.content
-  }
-
-TTAF.meta.copyright.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.meta.copyright.content.extra = empty
-TTAF.meta.copyright.content = text
-
-## desc - specifies description
-TTAF.meta.desc =
-  element ttm:desc {
-    TTAF.meta.desc.attlist,
-    TTAF.meta.desc.content
-  }
-
-TTAF.meta.desc.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.meta.desc.content.extra = empty
-TTAF.meta.desc.content = text
-
-## name - specifies name
-TTAF.meta.name =
-  element ttm:name {
-    TTAF.meta.name.attlist,
-    TTAF.meta.name.content
-  }
-
-TTAF.meta.name.attlist &amp;=
-  TTAF.Core.attrib.class,
-  attribute type { TTAF.MetadataNameType.datatype }
-
-TTAF.meta.name.content.extra = empty
-TTAF.meta.name.content = text
-
-## title - describes title
-TTAF.meta.title =
-  element ttm:title {
-    TTAF.meta.title.attlist,
-    TTAF.meta.title.content
-  }
-
-TTAF.meta.title.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.meta.title.content.extra = empty
-TTAF.meta.title.content = text
-
-## MetadataItems.class
-TTAF.MetadataItems.extra = empty
-TTAF.MetadataItems.class |=
-  TTAF.meta.agent |
-  TTAF.meta.copyright |
-  TTAF.meta.desc |
-  TTAF.meta.title |
-  TTAF.MetadataItems.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-metadata-attribs-module" id="rnc-dfxp-metadata-attribs-module"/>B.1.2.11 Metadata Attributes Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Metadata Attributes Module ..............................
-# .......................................................................
-
-namespace tt = "http://www.w3.org/ns/ttml"
-namespace ttm = "http://www.w3.org/ns/ttml#metadata"
-namespace local = ""
-
-# Standard Metadata Attributes
-
-TTAF.agent.attrib
-  = attribute ttm:agent { TTAF.Agent.datatype }?
-TTAF.role.attrib
-  = attribute ttm:role { TTAF.Role.datatype }?
-
-# Metadata Attribute Class
-
-TTAF.Metadata.attrib.class &amp;=
-  TTAF.agent.attrib,
-  TTAF.role.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-parameters-module" id="rnc-dfxp-parameters-module"/>B.1.2.12 Parameters Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Parameters Module ......................................
-# .......................................................................
-
-TTAF.Parameters.class |=
-  TTAF.ParameterItems.class
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-parameter-items-module" id="rnc-dfxp-parameter-items-module"/>B.1.2.13 Parameter Items Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Parameter Items Module .................................
-# .......................................................................
-
-namespace ttp = "http://www.w3.org/ns/ttml#parameter"
-
-# profile - profile definition or use declaration
-TTAF.parameters.profile =
-  element ttp:profile {
-    TTAF.parameters.profile.attlist,
-    TTAF.parameters.profile.content
-  }
-
-TTAF.parameters.profile.attlist &amp;=
-  TTAF.id.attrib,
-  attribute use { TTAF.Profile.datatype }?
-
-TTAF.parameters.profile.content.extra = empty
-TTAF.parameters.profile.content =
-  (TTAF.Metadata.class*,
-   TTAF.parameters.features*,
-   TTAF.parameters.extensions*,
-   TTAF.parameters.profile.content.extra*)
-
-# features - container for feature elements
-TTAF.parameters.features =
-  element ttp:features {
-    TTAF.parameters.features.attlist,
-    TTAF.parameters.features.content
-  }
-
-TTAF.parameters.features.attlist &amp;=
-  TTAF.id.attrib,
-  attribute xml:base { TTAF.URI.datatype }?
-
-TTAF.parameters.features.content.extra = empty
-TTAF.parameters.features.content =
-  (TTAF.Metadata.class*,
-   TTAF.parameters.feature*,
-   TTAF.parameters.features.content.extra*)
-
-# feature - feature requirements declaration
-TTAF.parameters.feature =
-  element ttp:feature {
-    TTAF.parameters.feature.attlist,
-    TTAF.parameters.feature.content
-  }
-
-TTAF.parameters.feature.attlist =
-  TTAF.id.attrib,
-  attribute value { TTAF.FeatureValue.datatype }?
-
-TTAF.parameters.feature.content =
-  TTAF.FeatureDesignator.datatype
-
-# extensions - container for extension elements
-TTAF.parameters.extensions =
-  element ttp:extensions {
-    TTAF.parameters.extensions.attlist,
-    TTAF.parameters.extensions.content
-  }
-
-TTAF.parameters.extensions.attlist &amp;=
-  TTAF.id.attrib,
-  attribute xml:base { TTAF.URI.datatype }?
-
-TTAF.parameters.extensions.content.extra = empty
-TTAF.parameters.extensions.content =
-  (TTAF.Metadata.class*,
-   TTAF.parameters.extension*,
-   TTAF.parameters.extensions.content.extra*)
-
-# extension - extension requirements declaration
-TTAF.parameters.extension =
-  element ttp:extension {
-    TTAF.parameters.extension.attlist,
-    TTAF.parameters.extension.content
-  }
-
-TTAF.parameters.extension.attlist =
-  TTAF.id.attrib,
-  attribute value { TTAF.ExtensionValue.datatype }?
-
-TTAF.parameters.extension.content =
-  TTAF.ExtensionDesignator.datatype
-
-## ParameterItems.class
-TTAF.ParameterItems.extra = empty
-TTAF.ParameterItems.class |=
-  TTAF.parameters.profile |
-  TTAF.ParameterItems.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-parameter-attribs-module" id="rnc-dfxp-parameter-attribs-module"/>B.1.2.14 Parameter Attributes Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Parameter Attributes Module ............................
-# .......................................................................
-
-namespace ttp = "http://www.w3.org/ns/ttml#parameter"
-
-# Standard Metadata Attributes
-
-TTAF.cellResolution.attrib
-  = attribute ttp:cellResolution { TTAF.CellResolution.datatype }?
-TTAF.clockMode.attrib
-  = attribute ttp:clockMode { TTAF.ClockMode.datatype }?
-TTAF.dropMode.attrib
-  = attribute ttp:dropMode { TTAF.DropMode.datatype }?
-TTAF.frameRate.attrib
-  = attribute ttp:frameRate { TTAF.FrameRate.datatype }?
-TTAF.frameRateMultiplier.attrib
-  = attribute ttp:frameRateMultiplier { TTAF.FrameRateMultiplier.datatype }?
-TTAF.markerMode.attrib
-  = attribute ttp:markerMode { TTAF.MarkerMode.datatype }?
-TTAF.profile.attrib
-  = attribute ttp:profile { TTAF.Profile.datatype }?
-TTAF.pixelAspectRatio.attrib
-  = attribute ttp:pixelAspectRatio { TTAF.PixelAspectRatio.datatype }?
-TTAF.subFrameRate.attrib
-  = attribute ttp:subFrameRate { TTAF.SubFrameRate.datatype }?
-TTAF.tickRate.attrib
-  = attribute ttp:tickRate { TTAF.TickRate.datatype }?
-TTAF.timeBase.attrib
-  = attribute ttp:timeBase { TTAF.TimeBase.datatype }?
-
-# Parameter Attribute Class
-
-TTAF.Parameter.attrib.class &amp;=
-  TTAF.cellResolution.attrib,
-  TTAF.clockMode.attrib,
-  TTAF.dropMode.attrib,
-  TTAF.frameRate.attrib,
-  TTAF.frameRateMultiplier.attrib,
-  TTAF.markerMode.attrib,
-  TTAF.pixelAspectRatio.attrib,
-  TTAF.profile.attrib,
-  TTAF.subFrameRate.attrib,
-  TTAF.tickRate.attrib,
-  TTAF.timeBase.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-styling-attribs-module" id="rnc-dfxp-styling-attribs-module"/>B.1.2.15 Styling Attributes Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Styling Attributes Module ..............................
-# .......................................................................
-
-namespace tt = "http://www.w3.org/ns/ttml"
-namespace tts = "http://www.w3.org/ns/ttml#styling"
-namespace local = ""
-
-# Standard Style Attributes
-
-TTAF.backgroundColor.attrib
-  = attribute tts:backgroundColor { TTAF.Color.datatype }?
-TTAF.color.attrib
-  = attribute tts:color { TTAF.Color.datatype }?
-TTAF.direction.attrib
-  = attribute tts:direction { TTAF.Direction.datatype }?
-TTAF.display.attrib
-  = attribute tts:display { TTAF.Display.datatype }?
-TTAF.displayAlign.attrib
-  = attribute tts:displayAlign { TTAF.DisplayAlign.datatype }?
-TTAF.extent.attrib
-  = attribute tts:extent { TTAF.Extent.datatype }?
-TTAF.fontFamily.attrib
-  = attribute tts:fontFamily { TTAF.FontFamily.datatype }?
-TTAF.fontSize.attrib
-  = attribute tts:fontSize { TTAF.FontSize.datatype }?
-TTAF.fontStyle.attrib
-  = attribute tts:fontStyle { TTAF.FontStyle.datatype }?
-TTAF.fontWeight.attrib
-  = attribute tts:fontWeight { TTAF.FontWeight.datatype }?
-TTAF.lineHeight.attrib
-  = attribute tts:lineHeight { TTAF.LineHeight.datatype }?
-TTAF.opacity.attrib
-  = attribute tts:opacity { TTAF.Opacity.datatype }?
-TTAF.origin.attrib
-  = attribute tts:origin { TTAF.Origin.datatype }?
-TTAF.overflow.attrib
-  = attribute tts:overflow { TTAF.Overflow.datatype }?
-TTAF.padding.attrib
-  = attribute tts:padding { TTAF.Padding.datatype }?
-TTAF.showBackground.attrib
-  = attribute tts:showBackground { TTAF.ShowBackground.datatype }?
-TTAF.textAlign.attrib
-  = attribute tts:textAlign { TTAF.TextAlign.datatype }?
-TTAF.textDecoration.attrib
-  = attribute tts:textDecoration { TTAF.TextDecoration.datatype }?
-TTAF.textOutline.attrib
-  = attribute tts:textOutline { TTAF.TextOutline.datatype }?
-TTAF.unicodeBidi.attrib
-  = attribute tts:unicodeBidi { TTAF.UnicodeBidi.datatype }?
-TTAF.visibility.attrib
-  = attribute tts:visibility { TTAF.Visibility.datatype }?
-TTAF.wrapOption.attrib
-  = attribute tts:wrapOption { TTAF.WrapOption.datatype }?
-TTAF.writingMode.attrib
-  = attribute tts:writingMode { TTAF.WritingMode.datatype }?
-TTAF.zIndex.attrib
-  = attribute tts:zIndex { TTAF.ZIndex.datatype }?
-
-# Extension Style Attributes
-
-TTAF.Styling.ForeignExtension.attrib =
-  attribute * - ( tt:* | tts:* | xml:* | local:* ) { text }
-
-# Styling Attribute Class
-
-TTAF.Styling.attrib.class &amp;=
-  TTAF.backgroundColor.attrib,
-  TTAF.color.attrib,
-  TTAF.direction.attrib,
-  TTAF.display.attrib,
-  TTAF.displayAlign.attrib,
-  TTAF.extent.attrib,
-  TTAF.fontFamily.attrib,
-  TTAF.fontSize.attrib,
-  TTAF.fontStyle.attrib,
-  TTAF.fontWeight.attrib,
-  TTAF.lineHeight.attrib,
-  TTAF.opacity.attrib,
-  TTAF.origin.attrib,
-  TTAF.overflow.attrib,
-  TTAF.padding.attrib,
-  TTAF.showBackground.attrib,
-  TTAF.textAlign.attrib,
-  TTAF.textDecoration.attrib,
-  TTAF.textOutline.attrib,
-  TTAF.unicodeBidi.attrib,
-  TTAF.visibility.attrib,
-  TTAF.wrapOption.attrib,
-  TTAF.writingMode.attrib,
-  TTAF.zIndex.attrib
-
-# Style Binding Attribute Class
-
-TTAF.StyleBinding.attrib.class &amp;=
-  TTAF.style.attrib
-
-# Styled Content Attribute Class
-
-TTAF.Styled.extra.attrib = empty
-TTAF.Styled.attrib.class &amp;=
-  TTAF.Styling.attrib.class,
-  TTAF.StyleBinding.attrib.class,
-  TTAF.Styled.extra.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-styling-module" id="rnc-dfxp-styling-module"/>B.1.2.16 Styling Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Styling Module .........................................
-# .......................................................................
-
-# style reference attribute; must reference /tt/head/styling/style
-TTAF.style.attrib
-  = attribute style { xsd:IDREFS }?
-
-# styling - generic styling container
-TTAF.styling =
-  element styling {
-    TTAF.styling.attlist,
-    TTAF.styling.content
-  }
-
-TTAF.styling.attlist &amp;=
-  TTAF.Core.attrib.class
-
-TTAF.styling.content.extra = empty
-TTAF.styling.content =
-  (TTAF.Metadata.class*,
-   TTAF.styling.defs.class*,
-   TTAF.styling.content.extra*)
-
-# style - style declaration
-TTAF.styling.style =
-  element style {
-    TTAF.styling.style.attlist,
-    TTAF.styling.style.content
-  }
-
-TTAF.styling.style.attlist =
-  TTAF.Core.attrib.class,
-  TTAF.style.attrib,
-  (TTAF.Styling.attrib.class |
-   TTAF.Styling.ForeignExtension.attrib+ )
-
-TTAF.styling.style.content.extra = empty
-TTAF.styling.style.content =
-  (TTAF.styling.style.content.extra)*
-
-# style definitions class
-TTAF.styling.defs.extra = empty
-TTAF.styling.defs.class = 
-  TTAF.styling.style
-  | TTAF.styling.defs.extra
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div><div class="div4">
-<h5><a name="rnc-dfxp-timing-attribs-module" id="rnc-dfxp-timing-attribs-module"/>B.1.2.17 Timing Attributes Module</h5><div class="exampleInner"><pre># .......................................................................
-# TT-AF 1.0 DFXP Timing Attributes Module ...............................
-# .......................................................................
-
-# Timing Attributes
-
-TTAF.timing.begin.attrib
-  = attribute begin { TTAF.TimeCoordinate.datatype }?
-TTAF.timing.dur.attrib
-  = attribute dur { TTAF.TimeDuration.datatype }?
-TTAF.timing.end.attrib
-  = attribute end { TTAF.TimeCoordinate.datatype }?
-TTAF.timing.timeContainer.attrib
-  = attribute timeContainer { TTAF.TimeContainer.datatype }?
-
-# Timing Interval Attribute class
-
-TTAF.TimingInterval.extra.attrib = empty
-TTAF.TimingInterval.attrib.class &amp;=
-  TTAF.timing.begin.attrib,
-  TTAF.timing.dur.attrib,
-  TTAF.timing.end.attrib,
-  TTAF.TimingInterval.extra.attrib
-
-# Timing Container Attribute class
-
-TTAF.TimingContainer.extra.attrib = empty
-TTAF.TimingContainer.attrib.class &amp;=
-  TTAF.timing.timeContainer.attrib,
-  TTAF.TimingContainer.extra.attrib
-
-# Timed Content Attribute Class
-
-TTAF.Timed.extra.attrib = empty
-TTAF.Timed.attrib.class &amp;=
-  TTAF.TimingInterval.attrib.class,
-  TTAF.Timed.extra.attrib
-
-# Timed Content Container Attribute Class
-
-TTAF.TimedContainer.extra.attrib = empty
-TTAF.TimedContainer.attrib.class &amp;=
-  TTAF.Timed.attrib.class,
-  TTAF.TimingContainer.attrib.class,
-  TTAF.TimedContainer.extra.attrib
-
-# .......................................................................
-# .......................................................................
-# .......................................................................
-</pre></div></div></div></div><div class="div2">
-<h3><a name="dfxp-schema-xsd" id="dfxp-schema-xsd"/>B.2 XML Schema Definition (XSD) Schema</h3><p>This section specifies a W3C XML Schema Definition (XSD) <a href="#xsd-1">[XML Schema Part 1]</a> based schema
-for DFXP Content, also available in a <a href="xsd/schema.zip">ZIP
-Archive</a>.</p><div class="div3">
-<h4><a name="xsd-dfxp-driver-schema" id="xsd-dfxp-driver-schema"/>B.2.1 Driver</h4><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-document.xsd"/&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div3">
-<h4><a name="xsd-dfxp-modules" id="xsd-dfxp-modules"/>B.2.2 Modules</h4><div class="div4">
-<h5><a name="xsd-dfxp-animation-module" id="xsd-dfxp-animation-module"/>B.2.2.1 Animation Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#styling"
-    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/&gt;
-  &lt;xs:attributeGroup name="set.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class" /&gt;
-    &lt;xs:attributeGroup ref="tt:Timed.attrib.class" /&gt;
-    &lt;xs:attributeGroup ref="tts:Styling.attrib.class" /&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="set.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:set.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="set" type="tt:set.eltype"/&gt;
-  &lt;xs:group name="Animation.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:element ref="tt:set"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-content-module" id="xsd-dfxp-content-module"/>B.2.2.2 Content Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-animation.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-layout.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-styling.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#metadata"
-    schemaLocation="ttaf1-dfxp-metadata-attribs.xsd"/&gt;
-  &lt;xs:attributeGroup name="body.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:TimedContainer.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:RegionBinding.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="ttm:Metadata.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="div.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:TimedContainer.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:RegionBinding.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="ttm:Metadata.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="p.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:TimedContainer.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:RegionBinding.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="ttm:Metadata.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="span.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:TimedContainer.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:RegionBinding.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="ttm:Metadata.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="br.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="ttm:Metadata.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="body.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="tt:div" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:body.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="div.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Block.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:div.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="p.eltype" mixed="true"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Inline.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:p.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="span.eltype" mixed="true"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Inline.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:span.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="br.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:br.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="body" type="tt:body.eltype"/&gt;
-  &lt;xs:element name="div" type="tt:div.eltype"/&gt;
-  &lt;xs:element name="p" type="tt:p.eltype"/&gt;
-  &lt;xs:element name="span" type="tt:span.eltype"/&gt;
-  &lt;xs:element name="br" type="tt:br.eltype"/&gt;
-  &lt;xs:group name="BlockNoDiv.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:element ref="tt:p"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-  &lt;xs:group name="Block.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:group ref="tt:BlockNoDiv.class"/&gt;
-      &lt;xs:element ref="tt:div"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-  &lt;xs:group name="InlineNoSpan.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:element ref="tt:br"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-  &lt;xs:group name="Inline.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:group ref="tt:InlineNoSpan.class"/&gt;
-      &lt;xs:element ref="tt:span"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-core-attribs-module" id="xsd-dfxp-core-attribs-module"/>B.2.2.3 Core Attributes Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:xml="http://www.w3.org/XML/1998/namespace"&gt;
-  &lt;xs:import namespace="http://www.w3.org/XML/1998/namespace"
-    schemaLocation="xml.xsd"/&gt;
-  &lt;xs:attributeGroup name="Core.ID.attrib.class"&gt;
-    &lt;xs:attribute ref="xml:id"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="Core.attrib.class"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute ref="xml:lang"/&gt;
-    &lt;xs:attribute ref="xml:space"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="Core.required.attrib.class"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute ref="xml:lang" use="required"/&gt;
-    &lt;xs:attribute ref="xml:space"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-datatypes-module" id="xsd-dfxp-datatypes-module"/>B.2.2.4 Data Types Module</h5><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml#datatype"
-        xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
-        xmlns:ttd="http://www.w3.org/ns/ttml#datatype"&gt;
-  &lt;xs:simpleType name="alpha"&gt;
-    &lt;xs:restriction base="xs:float"&gt;
-      &lt;xs:minInclusive value="0"/&gt;
-      &lt;xs:maxInclusive value="1"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="agent"&gt;
-    &lt;xs:restriction base="xs:IDREFS"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="cellResolution"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;positiveInteger positiveInteger&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="clockMode"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="local"/&gt;
-      &lt;xs:enumeration value="gps"/&gt;
-      &lt;xs:enumeration value="utc"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="color"&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="direction"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="ltr"/&gt;
-      &lt;xs:enumeration value="rtl"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="display"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="auto"/&gt;
-      &lt;xs:enumeration value="none"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="displayAlign"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="before"/&gt;
-      &lt;xs:enumeration value="center"/&gt;
-      &lt;xs:enumeration value="after"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="dropMode"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="dropNTSC"/&gt;
-      &lt;xs:enumeration value="dropPAL"/&gt;
-      &lt;xs:enumeration value="nonDrop"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="extensionDesignator"&gt;
-    &lt;xs:restriction base="xs:anyURI"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="extensionValue"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="optional"/&gt;
-      &lt;xs:enumeration value="required"/&gt;
-      &lt;xs:enumeration value="use"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="extent"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;auto | length length&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="featureDesignator"&gt;
-    &lt;xs:restriction base="xs:anyURI"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="featureValue"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="optional"/&gt;
-      &lt;xs:enumeration value="required"/&gt;
-      &lt;xs:enumeration value="use"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="fontFamily"&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="fontSize"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;length | length length&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="fontStyle"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="normal"/&gt;
-      &lt;xs:enumeration value="italic"/&gt;
-      &lt;xs:enumeration value="oblique"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="fontWeight"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="normal"/&gt;
-      &lt;xs:enumeration value="bold"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="frameRate"&gt;
-    &lt;xs:restriction base="xs:nonNegativeInteger"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="frameRateMultiplier"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;positiveInteger:positiveInteger&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"&gt;
-      &lt;xs:pattern value="\p{Nd}+\s+\p{Nd}+"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="lineHeight"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;normal | length&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="markerMode"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="continuous"/&gt;
-      &lt;xs:enumeration value="discontinuous"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="metadataAgentType"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="person"/&gt;
-      &lt;xs:enumeration value="character"/&gt;
-      &lt;xs:enumeration value="group"/&gt;
-      &lt;xs:enumeration value="organization"/&gt;
-      &lt;xs:enumeration value="other"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="metadataNameType"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="full"/&gt;
-      &lt;xs:enumeration value="family"/&gt;
-      &lt;xs:enumeration value="given"/&gt;
-      &lt;xs:enumeration value="alias"/&gt;
-      &lt;xs:enumeration value="other"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="metadataRoleBaseType"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;orphan simpleType retained in hope it can be used for role&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="action"/&gt;
-      &lt;xs:enumeration value="caption"/&gt;
-      &lt;xs:enumeration value="description"/&gt;
-      &lt;xs:enumeration value="dialog"/&gt;
-      &lt;xs:enumeration value="expletive"/&gt;
-      &lt;xs:enumeration value="kinesic"/&gt;
-      &lt;xs:enumeration value="lyrics"/&gt;
-      &lt;xs:enumeration value="music"/&gt;
-      &lt;xs:enumeration value="narration"/&gt;
-      &lt;xs:enumeration value="quality"/&gt;
-      &lt;xs:enumeration value="sound"/&gt;
-      &lt;xs:enumeration value="source"/&gt;
-      &lt;xs:enumeration value="suppressed"/&gt;
-      &lt;xs:enumeration value="reproduction"/&gt;
-      &lt;xs:enumeration value="thought"/&gt;
-      &lt;xs:enumeration value="title"/&gt;
-      &lt;xs:enumeration value="transcription"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="opacity"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;alpha&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="origin"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;auto | length length&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="overflow"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="visible"/&gt;
-      &lt;xs:enumeration value="hidden"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="padding"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;length length | length length length | length length length length&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="pixelAspectRatio"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;positiveInteger:positiveInteger&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"&gt;
-      &lt;xs:pattern value="\p{Nd}+\s+\p{Nd}+"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="profile"&gt;
-    &lt;xs:restriction base="xs:anyURI"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="role"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;metadataRoleBaseType | "x-"string&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:NMTOKENS"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="showBackground"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="always"/&gt;
-      &lt;xs:enumeration value="whenActive"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="subFrameRate"&gt;
-    &lt;xs:restriction base="xs:positiveInteger"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="textAlign"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="left"/&gt;
-      &lt;xs:enumeration value="center"/&gt;
-      &lt;xs:enumeration value="right"/&gt;
-      &lt;xs:enumeration value="start"/&gt;
-      &lt;xs:enumeration value="end"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="textDecoration"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="none"/&gt;
-      &lt;xs:enumeration value="underline"/&gt;
-      &lt;xs:enumeration value="noUnderline"/&gt;
-      &lt;xs:enumeration value="overline"/&gt;
-      &lt;xs:enumeration value="noOverline"/&gt;
-      &lt;xs:enumeration value="lineThrough"/&gt;
-      &lt;xs:enumeration value="noLineThrough"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="textOutline"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;none | length | length length | color length | color length length&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="tickRate"&gt;
-    &lt;xs:restriction base="xs:positiveInteger"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="timeBase"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="media"/&gt;
-      &lt;xs:enumeration value="smpte"/&gt;
-      &lt;xs:enumeration value="clock"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="timeContainer"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="par"/&gt;
-      &lt;xs:enumeration value="seq"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="timeCoordinate"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;timeExpression&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="timeDuration"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;timeExpression&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="unicodeBidi"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="normal"/&gt;
-      &lt;xs:enumeration value="embed"/&gt;
-      &lt;xs:enumeration value="bidiOverride"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="visibility"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="hidden"/&gt;
-      &lt;xs:enumeration value="visible"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="wrapOption"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="wrap"/&gt;
-      &lt;xs:enumeration value="noWrap"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="writingMode"&gt;
-    &lt;xs:restriction base="xs:token"&gt;
-      &lt;xs:enumeration value="lrtb"/&gt;
-      &lt;xs:enumeration value="rltb"/&gt;
-      &lt;xs:enumeration value="tbrl"/&gt;
-      &lt;xs:enumeration value="tblr"/&gt;
-      &lt;xs:enumeration value="lr"/&gt;
-      &lt;xs:enumeration value="rl"/&gt;
-      &lt;xs:enumeration value="tb"/&gt;
-    &lt;/xs:restriction&gt;
-  &lt;/xs:simpleType&gt;
-  &lt;xs:simpleType name="zIndex"&gt;
-    &lt;xs:annotation&gt;
-      &lt;xs:documentation&gt;auto | integer&lt;/xs:documentation&gt;
-    &lt;/xs:annotation&gt;
-    &lt;xs:restriction base="xs:string"/&gt;
-  &lt;/xs:simpleType&gt;
-&lt;/xs:schema&gt;
-
-
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-document-module" id="xsd-dfxp-document-module"/>B.2.2.5 Document Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
-  xmlns:ttp="http://www.w3.org/ns/ttml#parameter"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#metadata"
-    schemaLocation="ttaf1-dfxp-metadata-items.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#parameter"
-    schemaLocation="ttaf1-dfxp-parameter-items.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#styling"
-    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-head.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-content.xsd"/&gt;
-  &lt;xs:attributeGroup name="tt.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.required.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="ttp:Parameter.attrib.class"/&gt;
-    &lt;xs:attribute ref="tts:extent"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="tt.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:element ref="tt:head" minOccurs="0" maxOccurs="1"/&gt;
-      &lt;xs:element ref="tt:body" minOccurs="0" maxOccurs="1"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:tt.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="tt" type="tt:tt.eltype"/&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-head-module" id="xsd-dfxp-head-module"/>B.2.2.6 Header Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
-  xmlns:ttp="http://www.w3.org/ns/ttml#parameter"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-parameters.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-styling.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-layout.xsd"/&gt;
-  &lt;xs:attributeGroup name="head.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="head.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Parameters.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="tt:styling" minOccurs="0" maxOccurs="1"/&gt;
-      &lt;xs:element ref="tt:layout" minOccurs="0" maxOccurs="1"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:head.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="head" type="tt:head.eltype"/&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-layout-module" id="xsd-dfxp-layout-module"/>B.2.2.7 Layout Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-animation.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-styling.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#styling"
-    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/&gt;
-  &lt;xs:attributeGroup name="RegionBinding.attrib.class"&gt;
-    &lt;xs:attribute name="region" type="xs:IDREF"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="layout.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="region.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:TimedContainer.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="layout.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="tt:region" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:layout.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="region.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="tt:style" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:region.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="layout" type="tt:layout.eltype"/&gt;
-  &lt;xs:element name="region" type="tt:region.eltype"/&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-metadata-module" id="xsd-dfxp-metadata-module"/>B.2.2.8 Metadata Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#metadata"
-    schemaLocation="ttaf1-dfxp-metadata-items.xsd"/&gt;
-  &lt;xs:attributeGroup name="metadata.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="metadata.eltype" mixed="true"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:any namespace="##other" processContents="lax" minOccurs="0"
-        maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:metadata.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="metadata" type="tt:metadata.eltype"/&gt;
-  &lt;xs:group name="Metadata.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:group ref="ttm:MetadataItems.class"/&gt;
-      &lt;xs:element ref="tt:metadata"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-metadata-items-module" id="xsd-dfxp-metadata-items-module"/>B.2.2.9 Metadata Items Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml#metadata"
-  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttd="http://www.w3.org/ns/ttml#datatype"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#datatype"
-    schemaLocation="ttaf1-dfxp-datatypes.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml"
-    schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-metadata-attribs.xsd"/&gt;
-  &lt;xs:attributeGroup name="actor.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attribute name="agent" type="xs:IDREF"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="agent.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attribute name="type" type="ttd:metadataAgentType"
-    use="required"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="copyright.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="desc.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="name.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attribute name="type" type="ttd:metadataNameType"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="title.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="actor.eltype"&gt;
-    &lt;xs:attributeGroup ref="ttm:actor.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="agent.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:element ref="ttm:name" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="ttm:actor" minOccurs="0" maxOccurs="1"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="ttm:agent.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="copyright.eltype" mixed="true"&gt;
-    &lt;xs:attributeGroup ref="ttm:copyright.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="desc.eltype" mixed="true"&gt;
-    &lt;xs:attributeGroup ref="ttm:desc.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="name.eltype" mixed="true"&gt;
-    &lt;xs:attributeGroup ref="ttm:name.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="title.eltype" mixed="true"&gt;
-    &lt;xs:attributeGroup ref="ttm:title.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="actor" type="ttm:actor.eltype"/&gt;
-  &lt;xs:element name="agent" type="ttm:agent.eltype"/&gt;
-  &lt;xs:element name="copyright" type="ttm:copyright.eltype"/&gt;
-  &lt;xs:element name="desc" type="ttm:desc.eltype"/&gt;
-  &lt;xs:element name="name" type="ttm:name.eltype"/&gt;
-  &lt;xs:element name="title" type="ttm:title.eltype"/&gt;
-  &lt;xs:group name="MetadataItems.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:element ref="ttm:agent"/&gt;
-      &lt;xs:element ref="ttm:copyright"/&gt;
-      &lt;xs:element ref="ttm:desc"/&gt;
-      &lt;xs:element ref="ttm:title"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-metadata-attribs-module" id="xsd-dfxp-metadata-attribs-module"/>B.2.2.10 Metadata Attributes Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml#metadata"
-  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:ttd="http://www.w3.org/ns/ttml#datatype"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#datatype"
-    schemaLocation="ttaf1-dfxp-datatypes.xsd"/&gt;
-  &lt;xs:attribute name="agent" type="ttd:agent"/&gt;
-  &lt;xs:attribute name="role" type="ttd:role"/&gt;
-  &lt;xs:attributeGroup name="Metadata.attrib.class"&gt;
-    &lt;xs:attribute ref="ttm:agent"/&gt;
-    &lt;xs:attribute ref="ttm:role"/&gt;
-  &lt;/xs:attributeGroup&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-parameters-module" id="xsd-dfxp-parameters-module"/>B.2.2.11 Parameters Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttp="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#parameter"
-    schemaLocation="ttaf1-dfxp-parameter-items.xsd"/&gt;
-  &lt;xs:group name="Parameters.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:group ref="ttp:ParameterItems.class"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-parameter-items-module" id="xsd-dfxp-parameter-items-module"/>B.2.2.12 Parameter Items Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml#parameter"
-  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttd="http://www.w3.org/ns/ttml#datatype"
-  xmlns:ttp="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;xs:import namespace="http://www.w3.org/XML/1998/namespace"
-    schemaLocation="xml.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#datatype"
-    schemaLocation="ttaf1-dfxp-datatypes.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml"
-    schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-parameter-attribs.xsd"/&gt;
-  &lt;xs:attributeGroup name="profile.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute name="use" type="ttd:profile"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="features.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute ref="xml:base"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="feature.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute name="value" type="ttd:featureValue"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="extensions.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute ref="xml:base"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="extension.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.ID.attrib.class"/&gt;
-    &lt;xs:attribute name="value" type="ttd:extensionValue"/&gt;
-    &lt;xs:anyAttribute namespace="##other"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="profile.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:element ref="ttp:features" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="ttp:extensions" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="ttp:profile.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="features.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:element ref="ttp:feature" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="ttp:features.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="feature.eltype"&gt;
-    &lt;xs:simpleContent&gt;
-	  &lt;xs:extension base="ttd:featureDesignator"&gt;
-	    &lt;xs:attributeGroup ref="ttp:feature.attlist"/&gt;
-      &lt;/xs:extension&gt;
-    &lt;/xs:simpleContent&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="extensions.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:element ref="ttp:extension" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="ttp:extensions.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="extension.eltype"&gt;
-    &lt;xs:simpleContent&gt;
-	  &lt;xs:extension base="ttd:extensionDesignator"&gt;
-	    &lt;xs:attributeGroup ref="ttp:extension.attlist"/&gt;
-      &lt;/xs:extension&gt;
-    &lt;/xs:simpleContent&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="profile" type="ttp:profile.eltype"/&gt;
-  &lt;xs:element name="features" type="ttp:features.eltype"/&gt;
-  &lt;xs:element name="feature" type="ttp:feature.eltype"/&gt;
-  &lt;xs:element name="extensions" type="ttp:extensions.eltype"/&gt;
-  &lt;xs:element name="extension" type="ttp:extension.eltype"/&gt;
-  &lt;xs:group name="ParameterItems.class"&gt;
-    &lt;xs:choice&gt;
-      &lt;xs:element ref="ttp:profile"/&gt;
-    &lt;/xs:choice&gt;
-  &lt;/xs:group&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-parameter-attribs-module" id="xsd-dfxp-parameter-attribs-module"/>B.2.2.13 Parameter Attributes Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml#parameter"
-  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:ttd="http://www.w3.org/ns/ttml#datatype"
-  xmlns:ttp="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#datatype"
-    schemaLocation="ttaf1-dfxp-datatypes.xsd"/&gt;
-  &lt;xs:attribute name="cellResolution" type="ttd:cellResolution"/&gt;
-  &lt;xs:attribute name="clockMode" type="ttd:clockMode"/&gt;
-  &lt;xs:attribute name="dropMode" type="ttd:dropMode"/&gt;
-  &lt;xs:attribute name="frameRate" type="ttd:frameRate"/&gt;
-  &lt;xs:attribute name="frameRateMultiplier" type="ttd:frameRateMultiplier"/&gt;
-  &lt;xs:attribute name="markerMode" type="ttd:markerMode"/&gt;
-  &lt;xs:attribute name="profile" type="ttd:profile"/&gt;
-  &lt;xs:attribute name="pixelAspectRatio" type="ttd:pixelAspectRatio"/&gt;
-  &lt;xs:attribute name="subFrameRate" type="ttd:subFrameRate"/&gt;
-  &lt;xs:attribute name="tickRate" type="ttd:tickRate"/&gt;
-  &lt;xs:attribute name="timeBase" type="ttd:timeBase"/&gt;
-  &lt;xs:attributeGroup name="Parameter.attrib.class"&gt;
-    &lt;xs:attribute ref="ttp:cellResolution"/&gt;
-    &lt;xs:attribute ref="ttp:clockMode"/&gt;
-    &lt;xs:attribute ref="ttp:dropMode"/&gt;
-    &lt;xs:attribute ref="ttp:frameRate"/&gt;
-    &lt;xs:attribute ref="ttp:frameRateMultiplier"/&gt;
-    &lt;xs:attribute ref="ttp:markerMode"/&gt;
-    &lt;xs:attribute ref="ttp:profile"/&gt;
-    &lt;xs:attribute ref="ttp:pixelAspectRatio"/&gt;
-    &lt;xs:attribute ref="ttp:subFrameRate"/&gt;
-    &lt;xs:attribute ref="ttp:tickRate"/&gt;
-    &lt;xs:attribute ref="ttp:timeBase"/&gt;
-  &lt;/xs:attributeGroup&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-styling-attribs-module" id="xsd-dfxp-styling-attribs-module"/>B.2.2.14 Styling Attributes Module</h5><div class="exampleInner"><pre>&lt;?xml version="1.0" encoding="utf-8"?&gt;
-&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml#styling" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:ttd="http://www.w3.org/ns/ttml#datatype"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#datatype"
-    schemaLocation="ttaf1-dfxp-datatypes.xsd"/&gt;
-  &lt;xs:attribute name="backgroundColor" type="ttd:color"/&gt;
-  &lt;xs:attribute name="color" type="ttd:color"/&gt;
-  &lt;xs:attribute name="direction" type="ttd:direction"/&gt;
-  &lt;xs:attribute name="display" type="ttd:display"/&gt;
-  &lt;xs:attribute name="displayAlign" type="ttd:displayAlign"/&gt;
-  &lt;xs:attribute name="extent" type="ttd:extent"/&gt;
-  &lt;xs:attribute name="fontFamily" type="ttd:fontFamily"/&gt;
-  &lt;xs:attribute name="fontSize" type="ttd:fontSize"/&gt;
-  &lt;xs:attribute name="fontStyle" type="ttd:fontStyle"/&gt;
-  &lt;xs:attribute name="fontWeight" type="ttd:fontWeight"/&gt;
-  &lt;xs:attribute name="lineHeight" type="ttd:lineHeight"/&gt;
-  &lt;xs:attribute name="opacity" type="ttd:opacity"/&gt;
-  &lt;xs:attribute name="origin" type="ttd:origin"/&gt;
-  &lt;xs:attribute name="overflow" type="ttd:overflow"/&gt;
-  &lt;xs:attribute name="padding" type="ttd:padding"/&gt;
-  &lt;xs:attribute name="showBackground" type="ttd:showBackground"/&gt;
-  &lt;xs:attribute name="textAlign" type="ttd:textAlign"/&gt;
-  &lt;xs:attribute name="textDecoration" type="ttd:textDecoration"/&gt;
-  &lt;xs:attribute name="textOutline" type="ttd:textOutline"/&gt;
-  &lt;xs:attribute name="unicodeBidi" type="ttd:unicodeBidi"/&gt;
-  &lt;xs:attribute name="visibility" type="ttd:visibility"/&gt;
-  &lt;xs:attribute name="wrapOption" type="ttd:wrapOption"/&gt;
-  &lt;xs:attribute name="writingMode" type="ttd:writingMode"/&gt;
-  &lt;xs:attribute name="zIndex" type="ttd:zIndex"/&gt;
-  &lt;xs:attributeGroup name="Styling.attrib.class"&gt;
-    &lt;xs:attribute ref="tts:backgroundColor"/&gt;
-    &lt;xs:attribute ref="tts:color"/&gt;
-    &lt;xs:attribute ref="tts:direction"/&gt;
-    &lt;xs:attribute ref="tts:display"/&gt;
-    &lt;xs:attribute ref="tts:displayAlign"/&gt;
-    &lt;xs:attribute ref="tts:extent"/&gt;
-    &lt;xs:attribute ref="tts:fontFamily"/&gt;
-    &lt;xs:attribute ref="tts:fontSize"/&gt;
-    &lt;xs:attribute ref="tts:fontStyle"/&gt;
-    &lt;xs:attribute ref="tts:fontWeight"/&gt;
-    &lt;xs:attribute ref="tts:lineHeight"/&gt;
-    &lt;xs:attribute ref="tts:opacity"/&gt;
-    &lt;xs:attribute ref="tts:origin"/&gt;
-    &lt;xs:attribute ref="tts:overflow"/&gt;
-    &lt;xs:attribute ref="tts:padding"/&gt;
-    &lt;xs:attribute ref="tts:showBackground"/&gt;
-    &lt;xs:attribute ref="tts:textAlign"/&gt;
-    &lt;xs:attribute ref="tts:textDecoration"/&gt;
-    &lt;xs:attribute ref="tts:textOutline"/&gt;
-    &lt;xs:attribute ref="tts:unicodeBidi"/&gt;
-    &lt;xs:attribute ref="tts:visibility"/&gt;
-    &lt;xs:attribute ref="tts:wrapOption"/&gt;
-    &lt;xs:attribute ref="tts:writingMode"/&gt;
-    &lt;xs:attribute ref="tts:zIndex"/&gt;
-  &lt;/xs:attributeGroup&gt;
-&lt;/xs:schema&gt;
-
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-styling-module" id="xsd-dfxp-styling-module"/>B.2.2.15 Styling Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:tt="http://www.w3.org/ns/ttml"
-  xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
-  xmlns:tts="http://www.w3.org/ns/ttml#styling"&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/&gt;
-  &lt;xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#styling"
-    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/&gt;
-  &lt;xs:attributeGroup name="StyleBinding.attrib.class"&gt;
-    &lt;xs:attribute name="style" type="xs:IDREFS"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="Styled.attrib.class"&gt;
-    &lt;xs:attributeGroup ref="tt:StyleBinding.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tts:Styling.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="styling.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="style.attlist"&gt;
-    &lt;xs:attributeGroup ref="tt:Core.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:Styled.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:complexType name="styling.eltype"&gt;
-    &lt;xs:sequence&gt;
-      &lt;xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/&gt;
-      &lt;xs:element ref="tt:style" minOccurs="0" maxOccurs="unbounded"/&gt;
-    &lt;/xs:sequence&gt;
-    &lt;xs:attributeGroup ref="tt:styling.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:complexType name="style.eltype"&gt;
-    &lt;xs:attributeGroup ref="tt:style.attlist"/&gt;
-  &lt;/xs:complexType&gt;
-  &lt;xs:element name="styling" type="tt:styling.eltype"/&gt;
-  &lt;xs:element name="style" type="tt:style.eltype"/&gt;
-&lt;/xs:schema&gt;
-
-
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-timing-attribs-module" id="xsd-dfxp-timing-attribs-module"/>B.2.2.16 Timing Attributes Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/ns/ttml" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"
-  xmlns:ttd="http://www.w3.org/ns/ttml#datatype"
-  xmlns:tt="http://www.w3.org/ns/ttml"&gt;
-  &lt;xs:import namespace="http://www.w3.org/ns/ttml#datatype"
-    schemaLocation="ttaf1-dfxp-datatypes.xsd"/&gt;
-  &lt;xs:attributeGroup name="TimingInterval.attrib.class"&gt;
-    &lt;xs:attribute name="begin" type="ttd:timeCoordinate"/&gt;
-    &lt;xs:attribute name="dur" type="ttd:timeDuration"/&gt;
-    &lt;xs:attribute name="end" type="ttd:timeCoordinate"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="TimingContainer.attrib.class"&gt;
-    &lt;xs:attribute name="timeContainer" type="ttd:timeContainer"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="Timed.attrib.class"&gt;
-    &lt;xs:attributeGroup ref="tt:TimingInterval.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-  &lt;xs:attributeGroup name="TimedContainer.attrib.class"&gt;
-    &lt;xs:attributeGroup ref="tt:Timed.attrib.class"/&gt;
-    &lt;xs:attributeGroup ref="tt:TimingContainer.attrib.class"/&gt;
-  &lt;/xs:attributeGroup&gt;
-&lt;/xs:schema&gt;
-</pre></div></div><div class="div4">
-<h5><a name="xsd-dfxp-xml-attrs-module" id="xsd-dfxp-xml-attrs-module"/>B.2.2.17 XML Attributes Module</h5><div class="exampleInner"><pre>&lt;xs:schema targetNamespace="http://www.w3.org/XML/1998/namespace" xml:lang="en"
-  xmlns:xs="http://www.w3.org/2001/XMLSchema"&gt;
-  &lt;xs:attribute name="base" type="xs:anyURI"/&gt;
-  &lt;xs:attribute name="id" type="xs:ID"/&gt;
-  &lt;xs:attribute name="lang" type="xs:language"/&gt;
-  &lt;xs:attribute name="space"&gt;
-    &lt;xs:simpleType&gt;
-      &lt;xs:restriction base="xs:NCName"&gt;
-        &lt;xs:enumeration value="default"/&gt;
-        &lt;xs:enumeration value="preserve"/&gt;
-      &lt;/xs:restriction&gt;
-    &lt;/xs:simpleType&gt;
-  &lt;/xs:attribute&gt;
-&lt;/xs:schema&gt;
-</pre></div></div></div></div></div><div class="div1">
-<h2><a name="media-type-registration" id="media-type-registration"/>C Media Type Registration</h2><p><em>This appendix is normative.</em></p><p>This appendix registers a new MIME media type,
-"application/ttml+xml" in conformance with
-<a href="http://www.ietf.org/rfc/rfc4288.txt">BCP 13</a> and
-<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">Type name:</dt><dd><p>application</p></dd><dt class="label">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></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">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
-can be used to consume large amounts of memory, which may cause XML
-processors in constrained environments to fail.</p><p>In addition, because of the extensibility features for TTML and of XML
-in general, it is possible that "application/ttml+xml" may describe content
-that has security implications beyond those described here. However,
-if the processor follows only the normative semantics of the published
-specification, this content will be outside TTML namespaces and
-may be ignored. Only in the case where the processor recognizes and
-processes the additional content, or where further processing of that
-content is dispatched to other processors, would security issues
-potentially arise. And in that case, they would fall outside the
-domain of this registration document.</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
-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/></dd><dt class="label">Published specification:</dt><dd><p><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/><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 (public-tt@w3.org)</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 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
-labels one or more syntactic and/or semantic features defined by this
-specification, and (2) for each designated feature, whether the feature is mandatory
-or optional for a transformation or presentation processor.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>A TTML processor is said to <em>implement the transformation semantics</em> or
-<em>implement the presentation semantics</em> of feature designation <em>F</em>
-if it satisfies the requirements of this appendix with respect to the definition of
-feature designation <em>F</em> as pertains to transformation or
-presentation processing, respectively.</p></div><div class="div2">
-<h3><a name="feature-designations" id="feature-designations"/>D.1 Feature Designations</h3><p>A feature designation is expressed as a string that adheres to the following
-form:</p><div class="exampleInner"><pre>
-feature-designation
-  : feature-namespace designation
-
-feature-namespace
-  : <em>TT Feature Namespace</em>                    // http://www.w3.org/ns/ttml/feature/
-
-designation
-  : "#" token-char+
-
-token-char
-  : { XML NameChar }                        // XML 1.1 Production [4a]
-</pre></div><p>All values of <code>feature-designation</code> not defined by this specification are reserved
-for future standardization.</p><p>The following sub-sections define all feature designations, expressed
-as relative URIs (fragment identifiers) with respect to the 
-TT Feature Namespace base URI.</p><div class="div3">
-<h4><a name="feature-animation" id="feature-animation"/>D.1.1 #animation</h4><p>A TTML transformation processor supports the <code>#animation</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#animation"><b>11 Animation</b></a>:</p><ul><li><p><a href="#animation-vocabulary-set"><code>set</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#animation</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a name="feature-backgroundColor" id="feature-backgroundColor"/>D.1.2 #backgroundColor</h4><p>A TTML transformation processor supports the
-<code>#backgroundColor</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#backgroundColor</code> feature if it (1) implements presentation semantic support
-for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a name="feature-backgroundColor-block" id="feature-backgroundColor-block"/>D.1.3 #backgroundColor-block</h4><p>A TTML transformation processor supports the
-<code>#backgroundColor-block</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that would generate a
-block area during presentation processing.</p><p>A TTML presentation processor supports the
-<code>#backgroundColor-block</code> feature if it (1) implements presentation semantic
-support for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that generates a
-block area
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a name="feature-backgroundColor-inline" id="feature-backgroundColor-inline"/>D.1.4 #backgroundColor-inline</h4><p>A TTML transformation processor supports the
-<code>#backgroundColor-inline</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that would generate an
-inline area during presentation processing.</p><p>A TTML presentation processor supports the
-<code>#backgroundColor-inline</code> feature if it (1) implements presentation semantic
-support for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a content element that generates an
-inline area
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a name="feature-backgroundColor-region" id="feature-backgroundColor-region"/>D.1.5 #backgroundColor-region</h4><p>A TTML transformation processor supports the
-<code>#backgroundColor-region</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML presentation processor supports the
-<code>#backgroundColor-region</code> feature if it (1) implements presentation semantic
-support for the <a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space
-.</p></div><div class="div3">
-<h4><a name="feature-bidi" id="feature-bidi"/>D.1.6 #bidi</h4><p>A TTML processor supports the <code>#bidi</code> feature if it
-supports the following features:</p><ul><li><p><a href="#feature-direction"><code>#direction</code></a></p></li><li><p><a href="#feature-unicodeBidi"><code>#unicodeBidi</code></a></p></li><li><p><a href="#feature-writingMode-horizontal"><code>#writingMode-horizontal</code></a></p></li></ul></div><div class="div3">
-<h4><a name="feature-cellResolution" id="feature-cellResolution"/>D.1.7 #cellResolution</h4><p>A TTML transformation processor supports the
-<code>#cellResolution</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-cellResolution"><code>ttp:cellResolution</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#cellResolution</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-cellResolution"><code>ttp:cellResolution</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-clockMode" id="feature-clockMode"/>D.1.8 #clockMode</h4><p>A TTML transformation processor supports the
-<code>#clockMode</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#clockMode</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-clockMode-gps" id="feature-clockMode-gps"/>D.1.9 #clockMode-gps</h4><p>A TTML transformation processor supports the
-<code>#clockMode-gps</code> feature if it recognizes and is capable of
-transforming the <code>gps</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#clockMode-gps</code> feature if it implements presentation semantic support
-for the <code>gps</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-clockMode-local" id="feature-clockMode-local"/>D.1.10 #clockMode-local</h4><p>A TTML transformation processor supports the
-<code>#clockMode-local</code> feature if it recognizes and is capable of
-transforming the <code>local</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#clockMode-local</code> feature if it implements presentation semantic support
-for the <code>local</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-clockMode-utc" id="feature-clockMode-utc"/>D.1.11 #clockMode-utc</h4><p>A TTML transformation processor supports the
-<code>#clockMode-utc</code> feature if it recognizes and is capable of
-transforming the <code>utc</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#clockMode-utc</code> feature if it implements presentation semantic support
-for the <code>utc</code> value of the <a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-color" id="feature-color"/>D.1.12 #color</h4><p>A TTML transformation processor supports the
-<code>#color</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-color"><code>tts:color</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#color</code> feature if it (1) implements presentation semantic support
-for the <a href="#style-attribute-color"><code>tts:color</code></a>
-attribute
-and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least sixteen (16) values of color,
-including all primary and secondary colors of the SRGB color space.</p></div><div class="div3">
-<h4><a name="feature-content" id="feature-content"/>D.1.13 #content</h4><p>A TTML transformation processor supports the <code>#content</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#content"><b>7 Content</b></a>:</p><ul><li><p><a href="#document-structure-vocabulary-body"><code>body</code></a></p></li><li><p><a href="#content-vocabulary-div"><code>div</code></a></p></li><li><p><a href="#content-vocabulary-p"><code>p</code></a></p></li><li><p><a href="#content-vocabulary-span"><code>span</code></a></p></li><li><p><a href="#content-vocabulary-br"><code>br</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#content</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a name="feature-core" id="feature-core"/>D.1.14 #core</h4><p>A TTML transformation processor supports the <code>#core</code>
-feature if it recognizes and is capable of transforming the following
-core attributes vocabulary defined by <a href="#content"><b>7 Content</b></a>:</p><ul><li><p><a href="#content-attribute-id">@<code>xml:id</code></a></p></li><li><p><a href="#content-attribute-id">@<code>xml:lang</code></a></p></li><li><p><a href="#content-attribute-id">@<code>xml:space</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#core</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a name="feature-direction" id="feature-direction"/>D.1.15 #direction</h4><p>A TTML transformation processor supports the
-<code>#direction</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-direction"><code>tts:direction</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#direction</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-direction"><code>tts:direction</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-display" id="feature-display"/>D.1.16 #display</h4><p>A TTML transformation processor supports the
-<code>#display</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#display</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-display-block" id="feature-display-block"/>D.1.17 #display-block</h4><p>A TTML transformation processor supports the
-<code>#display-block</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that would generate a
-block area during presentation processing.</p><p>A TTML presentation processor supports the
-<code>#display-block</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that generates a
-block area.</p></div><div class="div3">
-<h4><a name="feature-display-inline" id="feature-display-inline"/>D.1.18 #display-inline</h4><p>A TTML transformation processor supports the
-<code>#display-inline</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that would generate an
-inline area during presentation processing.</p><p>A TTML presentation processor supports the
-<code>#display-inline</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a content element that generates an
-inline area.</p></div><div class="div3">
-<h4><a name="feature-display-region" id="feature-display-region"/>D.1.19 #display-region</h4><p>A TTML transformation processor supports the
-<code>#display-region</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML presentation processor supports the
-<code>#display-region</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-display"><code>tts:display</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></div><div class="div3">
-<h4><a name="feature-displayAlign" id="feature-displayAlign"/>D.1.20 #displayAlign</h4><p>A TTML transformation processor supports the
-<code>#displayAlign</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-displayAlign"><code>tts:displayAlign</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#displayAlign</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-displayAlign"><code>tts:displayAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-dropMode" id="feature-dropMode"/>D.1.21 #dropMode</h4><p>A TTML transformation processor supports the
-<code>#dropMode</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#dropMode</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-dropMode-dropNTSC" id="feature-dropMode-dropNTSC"/>D.1.22 #dropMode-dropNTSC</h4><p>A TTML transformation processor supports the
-<code>#dropMode-dropNTSC</code> feature if it recognizes and is capable of
-transforming the <code>dropNTSC</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#dropMode-dropNTSC</code> feature if it implements presentation semantic support
-for the <code>dropNTSC</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-dropMode-dropPAL" id="feature-dropMode-dropPAL"/>D.1.23 #dropMode-dropPAL</h4><p>A TTML transformation processor supports the
-<code>#dropMode-dropPAL</code> feature if it recognizes and is capable of
-transforming the <code>dropPAL</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#dropMode-dropPAL</code> feature if it implements presentation semantic support
-for the <code>dropPAL</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-dropMode-nonDrop" id="feature-dropMode-nonDrop"/>D.1.24 #dropMode-nonDrop</h4><p>A TTML transformation processor supports the
-<code>#dropMode-nonDrop</code> feature if it recognizes and is capable of
-transforming the <code>nonDrop</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#dropMode-nonDrop</code> feature if it implements presentation semantic support
-for the <code>nonDrop</code> value of the <a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-extent" id="feature-extent"/>D.1.25 #extent</h4><p>A TTML transformation processor supports the
-<code>#extent</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#extent</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-extent-region" id="feature-extent-region"/>D.1.26 #extent-region</h4><p>A TTML transformation processor supports the
-<code>#extent-region</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML presentation processor supports the
-<code>#extent-region</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></div><div class="div3">
-<h4><a name="feature-extent-root" id="feature-extent-root"/>D.1.27 #extent-root</h4><p>A TTML transformation processor supports the
-<code>#extent-root</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element.</p><p>A TTML presentation processor supports the
-<code>#extent-root</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-extent"><code>tts:extent</code></a>
-attribute when applied to a <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element.</p></div><div class="div3">
-<h4><a name="feature-fontFamily" id="feature-fontFamily"/>D.1.28 #fontFamily</h4><p>A TTML transformation processor supports the
-<code>#fontFamily</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontFamily</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontFamily-generic" id="feature-fontFamily-generic"/>D.1.29 #fontFamily-generic</h4><p>A TTML transformation processor supports the
-<code>#fontFamily-generic</code> feature if it recognizes and is
-capable of transforming <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontFamily-generic</code> feature if it implements presentation semantic
-support for <a href="#style-value-genericFamilyName">&lt;genericFamilyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontFamily-non-generic" id="feature-fontFamily-non-generic"/>D.1.30 #fontFamily-non-generic</h4><p>A TTML transformation processor supports the
-<code>#fontFamily-non-generic</code> feature if it recognizes and is
-capable of transforming <a href="#style-value-familyName">&lt;familyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontFamily-non-generic</code> feature if it implements presentation semantic
-support for <a href="#style-value-familyName">&lt;familyName&gt;</a>
-values when used with the <a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontSize" id="feature-fontSize"/>D.1.31 #fontSize</h4><p>A TTML transformation processor supports the
-<code>#fontSize</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontSize</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontSize-anamorphic" id="feature-fontSize-anamorphic"/>D.1.32 #fontSize-anamorphic</h4><p>A TTML transformation processor supports the
-<code>#fontSize-anamorphic</code> feature if it recognizes and is
-capable of transforming values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of two <a href="#style-value-length">&lt;length&gt;</a> specifications.</p><p>A TTML presentation processor supports the
-<code>#fontSize-anamorphic</code> feature if it implements presentation semantic
-support for defined values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of two <a href="#style-value-length">&lt;length&gt;</a> specifications.</p></div><div class="div3">
-<h4><a name="feature-fontSize-isomorphic" id="feature-fontSize-isomorphic"/>D.1.33 #fontSize-isomorphic</h4><p>A TTML transformation processor supports the
-<code>#fontSize-isomorphic</code> feature if it recognizes and is
-capable of transforming values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of a single <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML presentation processor supports the
-<code>#fontSize-isomorphic</code> feature if it implements presentation semantic
-support for defined values of the <a href="#style-attribute-fontSize"><code>tts:fontSize</code></a>
-attribute that consist of a single <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a name="feature-fontStyle" id="feature-fontStyle"/>D.1.34 #fontStyle</h4><p>A TTML transformation processor supports the
-<code>#fontStyle</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontStyle</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontStyle-italic" id="feature-fontStyle-italic"/>D.1.35 #fontStyle-italic</h4><p>A TTML transformation processor supports the
-<code>#fontStyle-italic</code> feature if it recognizes and is
-capable of transforming the <code>italic</code> value of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontStyle-italic</code> feature if it implements presentation semantic
-support for the <code>italic</code> of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontStyle-oblique" id="feature-fontStyle-oblique"/>D.1.36 #fontStyle-oblique</h4><p>A TTML transformation processor supports the
-<code>#fontStyle-oblique</code> feature if it recognizes and is
-capable of transforming the <code>oblique</code> value of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontStyle-oblique</code> feature if it implements presentation semantic
-support for the <code>oblique</code> of the <a href="#style-attribute-fontStyle"><code>tts:fontStyle</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontWeight" id="feature-fontWeight"/>D.1.37 #fontWeight</h4><p>A TTML transformation processor supports the
-<code>#fontWeight</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontWeight</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-fontWeight-bold" id="feature-fontWeight-bold"/>D.1.38 #fontWeight-bold</h4><p>A TTML transformation processor supports the
-<code>#fontWeight-bold</code> feature if it recognizes and is
-capable of transforming <code>bold</code> value of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#fontWeight-bold</code> feature if it implements presentation semantic
-support for the <code>bold</code> of the <a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-frameRate" id="feature-frameRate"/>D.1.39 #frameRate</h4><p>A TTML transformation processor supports the
-<code>#frameRate</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-frameRate"><code>ttp:frameRate</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#frameRate</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-frameRate"><code>ttp:frameRate</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-frameRateMultiplier" id="feature-frameRateMultiplier"/>D.1.40 #frameRateMultiplier</h4><p>A TTML transformation processor supports the
-<code>#frameRateMultiplier</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-frameRateMultiplier"><code>ttp:frameRateMultiplier</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#frameRateMultiplier</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-frameRateMultiplier"><code>ttp:frameRateMultiplier</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-layout" id="feature-layout"/>D.1.41 #layout</h4><p>A TTML transformation processor supports the <code>#layout</code>
-feature if it (1) recognizes and is capable of transforming the following
-vocabulary defined by <a href="#layout"><b>9 Layout</b></a>:</p><ul><li><p><a href="#layout-vocabulary-layout"><code>layout</code></a></p></li><li><p><a href="#layout-vocabulary-region"><code>region</code></a></p></li><li><p><a href="#layout-attribute-region">@<code>region</code></a></p></li></ul><p>and (2) supports the following attributes when applied to the
-<a href="#layout-vocabulary-region"><code>region</code></a> element:</p><ul><li><p><a href="#style-attribute-extent"><code>tts:extent</code></a></p></li><li><p><a href="#style-attribute-origin"><code>tts:origin</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#layout</code>
-feature if it implements presentation semantic support for the
-same vocabulary and features enumerated above.</p></div><div class="div3">
-<h4><a name="feature-length" id="feature-length"/>D.1.42 #length</h4><p>A TTML transformation processor supports the <code>#length</code>
-feature if it recognizes and is capable of transforming all defined
-values of the <a href="#style-value-length">&lt;length&gt;</a>
-style value expression.</p><p>A TTML presentation processor supports the <code>#length</code>
-feature if it implements presentation semantic support for all defined values of
-the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p></div><div class="div3">
-<h4><a name="feature-length-cell" id="feature-length-cell"/>D.1.43 #length-cell</h4><p>A TTML transformation processor supports the
-<code>#length-cell</code> feature if it recognizes and is capable of
-transforming scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>c</code> (cell) units.</p><p>A TTML presentation processor supports the
-<code>#length-cell</code> feature if it implements presentation semantic support
-for scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>c</code> (cell) units.</p></div><div class="div3">
-<h4><a name="feature-length-em" id="feature-length-em"/>D.1.44 #length-em</h4><p>A TTML transformation processor supports the
-<code>#length-em</code> feature if it recognizes and is capable of
-transforming scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>em</code> (EM) units.</p><p>A TTML presentation processor supports the
-<code>#length-em</code> feature if it implements presentation semantic support
-for scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>em</code> (EM) units.</p></div><div class="div3">
-<h4><a name="feature-length-integer" id="feature-length-integer"/>D.1.45 #length-integer</h4><p>A TTML transformation processor supports the
-<code>#length-integer</code> feature if it recognizes and is
-capable of transforming integer values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML presentation processor supports the
-<code>#length-integer</code> feature if it implements presentation semantic
-support for integer values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p></div><div class="div3">
-<h4><a name="feature-length-negative" id="feature-length-negative"/>D.1.46 #length-negative</h4><p>A TTML transformation processor supports the
-<code>#length-negative</code> feature if it recognizes and is
-capable of transforming negative values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML presentation processor supports the
-<code>#length-negative</code> feature if it implements presentation semantic
-support for negative values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p></div><div class="div3">
-<h4><a name="feature-length-percentage" id="feature-length-percentage"/>D.1.47 #length-percentage</h4><p>A TTML transformation processor supports the
-<code>#length-percentage</code> feature if it recognizes and is
-capable of transforming percentage values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML presentation processor supports the
-<code>#length-percentage</code> feature if it implements presentation semantic
-support for percentage values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p></div><div class="div3">
-<h4><a name="feature-length-pixel" id="feature-length-pixel"/>D.1.48 #length-pixel</h4><p>A TTML transformation processor supports the
-<code>#length-pixel</code> feature if it recognizes and is capable of
-transforming scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>px</code> (pixel) units.</p><p>A TTML presentation processor supports the
-<code>#length-pixel</code> feature if it implements presentation semantic support
-for scalar values of the <a href="#style-value-length">&lt;length&gt;</a> style value expression
-that use <code>px</code> (pixel) units.</p></div><div class="div3">
-<h4><a name="feature-length-positive" id="feature-length-positive"/>D.1.49 #length-positive</h4><p>A TTML transformation processor supports the
-<code>#length-positive</code> feature if it recognizes and is
-capable of transforming positive values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML presentation processor supports the
-<code>#length-positive</code> feature if it implements presentation semantic
-support for positive values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p></div><div class="div3">
-<h4><a name="feature-length-real" id="feature-length-real"/>D.1.50 #length-real</h4><p>A TTML transformation processor supports the
-<code>#length-real</code> feature if it recognizes and is
-capable of transforming real values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.</p><p>A TTML presentation processor supports the
-<code>#length-real</code> feature if it implements presentation semantic
-support for real values of the <a href="#style-value-length">&lt;length&gt;</a> style value
-expression.
-</p></div><div class="div3">
-<h4><a name="feature-lineBreak-uax14" id="feature-lineBreak-uax14"/>D.1.51 #lineBreak-uax14</h4><p>A TTML transformation processor supports the
-<code>#lineBreak-uax14</code> feature if it recognizes and is capable of
-transforming requirements expressed by <a href="#uax14">[UAX14]</a> into its
-target document space.</p><p>A TTML presentation processor supports the
-<code>#lineBreak-uax14</code> feature if it implements presentation semantic support
-for <a href="#uax14">[UAX14]</a> as applies to line breaking.</p></div><div class="div3">
-<h4><a name="feature-lineHeight" id="feature-lineHeight"/>D.1.52 #lineHeight</h4><p>A TTML transformation processor supports the
-<code>#lineHeight</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-lineHeight"><code>tts:lineHeight</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#lineHeight</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-lineHeight"><code>tts:lineHeight</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-markerMode" id="feature-markerMode"/>D.1.53 #markerMode</h4><p>A TTML transformation processor supports the
-<code>#markerMode</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#markerMode</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-markerMode-continuous" id="feature-markerMode-continuous"/>D.1.54 #markerMode-continuous</h4><p>A TTML transformation processor supports the
-<code>#markerMode-continuous</code> feature if it recognizes and is capable of
-transforming the <code>continuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#markerMode-continuous</code> feature if it implements presentation semantic support
-for the <code>continuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-markerMode-discontinuous" id="feature-markerMode-discontinuous"/>D.1.55 #markerMode-discontinuous</h4><p>A TTML transformation processor supports the
-<code>#markerMode-discontinuous</code> feature if it recognizes and is capable of
-transforming the <code>discontinuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#markerMode-discontinuous</code> feature if it implements presentation semantic support
-for the <code>discontinuous</code> value of the <a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-metadata" id="feature-metadata"/>D.1.56 #metadata</h4><p>A TTML transformation processor supports the <code>#metadata</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#metadata"><b>12 Metadata</b></a>:</p><ul><li><p><a href="#metadata-vocabulary-metadata"><code>metadata</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:title</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:desc</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:copyright</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:agent</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:name</code></a></p></li><li><p><a href="#metadata-vocabulary-title"><code>ttm:actor</code></a></p></li><li><p><a href="#metadata-attribute-agent">@<code>ttm:agent</code></a></p></li><li><p><a href="#metadata-attribute-role">@<code>ttm:role</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#metadata</code>
-feature if it recognizes and is capable of presenting the information
-expressed by the same vocabulary enumerated above.</p><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not define a standardized form for the
-presentation of metadata information. The presentation or ability to
-present metadata information is considered to be implementation
-dependent.</p></div></div><div class="div3">
-<h4><a name="feature-nested-div" id="feature-nested-div"/>D.1.57 #nested-div</h4><p>A TTML transformation processor supports the <code>#nested-div</code>
-feature if it recognizes and is capable of transforming nested
-<a href="#content-vocabulary-div"><code>div</code></a> elements.</p><p>A TTML presentation processor supports the <code>#nested-div</code>
-feature if it implements presentation semantic support for nested
-<a href="#content-vocabulary-div"><code>div</code></a> elements.</p></div><div class="div3">
-<h4><a name="feature-nested-span" id="feature-nested-span"/>D.1.58 #nested-span</h4><p>A TTML transformation processor supports the <code>#nested-span</code>
-feature if it recognizes and is capable of transforming nested
-<a href="#content-vocabulary-span"><code>span</code></a> elements.</p><p>A TTML presentation processor supports the <code>#nested-span</code>
-feature if it implements presentation semantic support for nested
-<a href="#content-vocabulary-span"><code>span</code></a> elements.</p></div><div class="div3">
-<h4><a name="feature-opacity" id="feature-opacity"/>D.1.59 #opacity</h4><p>A TTML transformation processor supports the
-<code>#opacity</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-opacity"><code>tts:opacity</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#opacity</code> feature if it (1) implements presentation semantic support for
-the <a href="#style-attribute-opacity"><code>tts:opacity</code></a>
-attribute and (2) is capable of displaying or generating an output display
-signal that distinguishes between at least eight (8) values of opacity.</p></div><div class="div3">
-<h4><a name="feature-origin" id="feature-origin"/>D.1.60 #origin</h4><p>A TTML transformation processor supports the
-<code>#origin</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-origin"><code>tts:origin</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#origin</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-origin"><code>tts:origin</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-overflow" id="feature-overflow"/>D.1.61 #overflow</h4><p>A TTML transformation processor supports the
-<code>#overflow</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#overflow</code> feature if it implements presentation semantic support for
-all defined values of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-overflow-visible" id="feature-overflow-visible"/>D.1.62 #overflow-visible</h4><p>A TTML transformation processor supports the
-<code>#overflow-visible</code> feature if it recognizes and is capable of
-transforming the <code>visible</code> value of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#overflow-visible</code> feature if it implements presentation semantic support for
-the <code>visible</code> value of the <a href="#style-attribute-overflow"><code>tts:overflow</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-padding" id="feature-padding"/>D.1.63 #padding</h4><p>A TTML transformation processor supports the
-<code>#padding</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-padding"><code>tts:padding</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#padding</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-padding"><code>tts:padding</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-padding-1" id="feature-padding-1"/>D.1.64 #padding-1</h4><p>A TTML transformation processor supports the
-<code>#padding-1</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of one <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML presentation processor supports the <code>#padding-1</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of one <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a name="feature-padding-2" id="feature-padding-2"/>D.1.65 #padding-2</h4><p>A TTML transformation processor supports the
-<code>#padding-2</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of two <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML presentation processor supports the <code>#padding-2</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of two <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a name="feature-padding-3" id="feature-padding-3"/>D.1.66 #padding-3</h4><p>A TTML transformation processor supports the
-<code>#padding-3</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of three <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML presentation processor supports the <code>#padding-3</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of three <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a name="feature-padding-4" id="feature-padding-4"/>D.1.67 #padding-4</h4><p>A TTML transformation processor supports the
-<code>#padding-4</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of four <a href="#style-value-length">&lt;length&gt;</a> specification.</p><p>A TTML presentation processor supports the <code>#padding-4</code>
-feature if it implements presentation semantic support for values of the <a href="#style-attribute-padding"><code>tts:padding</code></a> attribute
-that consist of four <a href="#style-value-length">&lt;length&gt;</a> specification.</p></div><div class="div3">
-<h4><a name="feature-pixelAspectRatio" id="feature-pixelAspectRatio"/>D.1.68 #pixelAspectRatio</h4><p>A TTML transformation processor supports the
-<code>#pixelAspectRatio</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-pixelAspectRatio"><code>ttp:pixelAspectRatio</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#pixelAspectRatio</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-pixelAspectRatio"><code>ttp:pixelAspectRatio</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-presentation" id="feature-presentation"/>D.1.69 #presentation</h4><p>A TTML processor supports the
-<code>#presentation</code> feature if it
-(1) satisfies the generic processor criteria defined by 
-<a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a>,
-(2) implements support for the region and line layout
-semantics defined by <a href="#semantics-region-layout"><b>9.3 Region Layout and Presentation</b></a> and
-<a href="#semantics-line-layout"><b>9.4 Line Layout</b></a>, respectively, and
-(3) implements presentation semantics for the following features:</p><ul><li><p><a href="#content"><code>#content</code></a></p></li><li><p><a href="#feature-core"><code>#core</code></a></p></li><li><p><a href="#feature-profile"><code>#profile</code></a></p></li><li><p><a href="#feature-structure"><code>#structure</code></a></p></li><li><p><a href="#feature-time-offset"><code>#time-offset</code></a></p></li><li><p><a href="#timing"><code>#timing</code></a></p></li></ul><p>
-In addition, a TTML processor that supports the
-<code>#presentation</code> feature should satisfy the user agent
-accessibility guidelines specified by <a href="#uaag">[UAAG]</a>.</p></div><div class="div3">
-<h4><a name="feature-profile" id="feature-profile"/>D.1.70 #profile</h4><p>A TTML transformation processor supports the <code>#profile</code>
-feature if it recognizes and is capable of transforming the
-<a href="#parameter-attribute-profile"><code>ttp:profile</code></a>
-attribute on the <a href="#document-structure-vocabulary-tt"><code>tt</code></a> element and
-transforming the following vocabulary defined by
-<a href="#parameter-element-vocabulary"><b>6.1 Parameter Element Vocabulary</b></a>:</p><ul><li><p><a href="#parameter-vocabulary-profile"><code>ttp:profile</code></a></p></li><li><p><a href="#parameter-vocabulary-features"><code>ttp:features</code></a></p></li><li><p><a href="#parameter-vocabulary-feature"><code>ttp:feature</code></a></p></li><li><p><a href="#parameter-vocabulary-extensions"><code>ttp:extensions</code></a></p></li><li><p><a href="#parameter-vocabulary-extension"><code>ttp:extension</code></a></p></li></ul><p>A TTML presentation processor supports the
-<code>#profile</code> feature if it implements presentation semantic support
-for the same vocabulary specified above.</p></div><div class="div3">
-<h4><a name="feature-showBackground" id="feature-showBackground"/>D.1.71 #showBackground</h4><p>A TTML transformation processor supports the
-<code>#showBackground</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-showBackground"><code>tts:showBackground</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#showBackground</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-showBackground"><code>tts:showBackground</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-structure" id="feature-structure"/>D.1.72 #structure</h4><p>A TTML transformation processor supports the <code>#structure</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#content"><b>7 Content</b></a>:</p><ul><li><p><a href="#document-structure-vocabulary-tt"><code>tt</code></a></p></li><li><p><a href="#document-structure-vocabulary-head"><code>head</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#structure</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a name="feature-styling" id="feature-styling"/>D.1.73 #styling</h4><p>A TTML transformation processor supports the <code>#styling</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#styling"><b>8 Styling</b></a>:</p><ul><li><p><a href="#styling-vocabulary-styling"><code>styling</code></a></p></li><li><p><a href="#styling-vocabulary-style"><code>style</code></a></p></li><li><p><a href="#style-attribute-style">@<code>style</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#styling</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a name="feature-styling-chained" id="feature-styling-chained"/>D.1.74 #styling-chained</h4><p>A TTML transformation processor supports the
-<code>#styling-chained</code> feature if it recognizes and is capable
-of transforming chained style association as defined by <a href="#semantics-style-association-chained-referential"><b>8.4.1.3 Chained Referential Styling</b></a>.</p><p>A TTML presentation processor supports the
-<code>#styling-chained</code> feature if it implements presentation semantic
-support for chained style association as defined by <a href="#semantics-style-association-chained-referential"><b>8.4.1.3 Chained Referential Styling</b></a>.</p></div><div class="div3">
-<h4><a name="feature-styling-inheritance-content" id="feature-styling-inheritance-content"/>D.1.75 #styling-inheritance-content</h4><p>A TTML transformation processor supports the
-<code>#styling-inheritance</code> feature if it recognizes and is
-capable of transforming content style inheritance as defined by
-<a href="#semantics-style-inheritance-content"><b>8.4.2.1 Content Style Inheritance</b></a>.</p><p>A TTML presentation processor supports the
-<code>#styling-inheritance-content</code> feature if it implements
-presentation semantic support for content style inheritance as defined by <a href="#semantics-style-inheritance-content"><b>8.4.2.1 Content Style Inheritance</b></a>.</p></div><div class="div3">
-<h4><a name="feature-styling-inheritance-region" id="feature-styling-inheritance-region"/>D.1.76 #styling-inheritance-region</h4><p>A TTML transformation processor supports the
-<code>#styling-inheritance</code> feature if it recognizes and is
-capable of transforming region style inheritance as defined by
-<a href="#semantics-style-inheritance-region"><b>8.4.2.2 Region Style Inheritance</b></a>.</p><p>A TTML presentation processor supports the
-<code>#styling-inheritance-region</code> feature if it implements
-presentation semantic support for region style inheritance as defined by <a href="#semantics-style-inheritance-region"><b>8.4.2.2 Region Style Inheritance</b></a>.</p></div><div class="div3">
-<h4><a name="feature-styling-inline" id="feature-styling-inline"/>D.1.77 #styling-inline</h4><p>A TTML transformation processor supports the
-<code>#styling-inline</code> feature if it recognizes and is capable
-of transforming inline style association as defined by <a href="#semantics-style-association-inline"><b>8.4.1.1 Inline Styling</b></a>.</p><p>A TTML presentation processor supports the
-<code>#styling-inline</code> feature if it implements presentation semantic support
-for inline style association as defined by <a href="#semantics-style-association-inline"><b>8.4.1.1 Inline Styling</b></a>.</p></div><div class="div3">
-<h4><a name="feature-styling-nested" id="feature-styling-nested"/>D.1.78 #styling-nested</h4><p>A TTML transformation processor supports the
-<code>#styling-nested</code> feature if it recognizes and is capable
-of transforming nested style association as defined by <a href="#semantics-style-association-nested"><b>8.4.1.4 Nested Styling</b></a>.</p><p>A TTML presentation processor supports the
-<code>#styling-nested</code> feature if it implements presentation semantic support
-for nested style association as defined by <a href="#semantics-style-association-nested"><b>8.4.1.4 Nested Styling</b></a>.</p></div><div class="div3">
-<h4><a name="feature-styling-referential" id="feature-styling-referential"/>D.1.79 #styling-referential</h4><p>A TTML transformation processor supports the
-<code>#styling-referential</code> feature if it recognizes and is capable
-of transforming referential style association as defined by <a href="#semantics-style-association-referential"><b>8.4.1.2 Referential Styling</b></a>.</p><p>A TTML presentation processor supports the
-<code>#styling-referential</code> feature if it implements presentation semantic
-support for referential style association as defined by <a href="#semantics-style-association-referential"><b>8.4.1.2 Referential Styling</b></a>.</p></div><div class="div3">
-<h4><a name="feature-subFrameRate" id="feature-subFrameRate"/>D.1.80 #subFrameRate</h4><p>A TTML transformation processor supports the
-<code>#subFrameRate</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-subFrameRate"><code>ttp:subFrameRate</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#subFrameRate</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-subFrameRate"><code>ttp:subFrameRate</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textAlign" id="feature-textAlign"/>D.1.81 #textAlign</h4><p>A TTML transformation processor supports the
-<code>#textAlign</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textAlign</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textAlign-absolute" id="feature-textAlign-absolute"/>D.1.82 #textAlign-absolute</h4><p>A TTML transformation processor supports the
-<code>#textAlign-absolute</code> feature if it recognizes and is
-capable of transforming the <code>left</code>, <code>center</code>,
-and <code>right</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textAlign-absolute</code> feature if it implements presentation semantic
-support for the <code>left</code>, <code>center</code>, and
-<code>right</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textAlign-relative" id="feature-textAlign-relative"/>D.1.83 #textAlign-relative</h4><p>A TTML transformation processor supports the
-<code>#textAlign-relative</code> feature if it recognizes and is
-capable of transforming the <code>start</code>, <code>center</code>,
-and <code>end</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textAlign-relative</code> feature if it implements presentation semantic
-support for the <code>start</code>, <code>center</code>, and
-<code>end</code> values of the <a href="#style-attribute-textAlign"><code>tts:textAlign</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textDecoration" id="feature-textDecoration"/>D.1.84 #textDecoration</h4><p>A TTML transformation processor supports the
-<code>#textDecoration</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textDecoration</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textDecoration-over" id="feature-textDecoration-over"/>D.1.85 #textDecoration-over</h4><p>A TTML transformation processor supports the
-<code>#textDecoration-over</code> feature if it recognizes and is
-capable of transforming the <code>overline</code> and
-<code>noOverline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textDecoration-over</code> feature if it implements
-presentation semantic support for the <code>overline</code> and
-<code>noOverline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textDecoration-through" id="feature-textDecoration-through"/>D.1.86 #textDecoration-through</h4><p>A TTML transformation processor supports the
-<code>#textDecoration-through</code> feature if it recognizes and is
-capable of transforming the <code>lineThrough</code> and
-<code>noLineThrough</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textDecoration-through</code> feature if it implements
-presentation semantic support for the <code>lineThrough</code> and
-<code>noLineThrough</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textDecoration-under" id="feature-textDecoration-under"/>D.1.87 #textDecoration-under</h4><p>A TTML transformation processor supports the
-<code>#textDecoration-under</code> feature if it recognizes and is
-capable of transforming the <code>underline</code> and
-<code>noUnderline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textDecoration-under</code> feature if it implements
-presentation semantic support for the <code>underline</code> and
-<code>noUnderline</code> values of the <a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textOutline" id="feature-textOutline"/>D.1.88 #textOutline</h4><p>A TTML transformation processor supports the
-<code>#textOutline</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#textOutline</code> feature if it implements presentation semantic support
-for the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-textOutline-blurred" id="feature-textOutline-blurred"/>D.1.89 #textOutline-blurred</h4><p>A TTML transformation processor supports the
-<code>#textOutline-blurred</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that includes a blur radius specification.</p><p>A TTML presentation processor supports the
-<code>#textOutline-blurred</code> feature if it implements presentation semantic support
-for values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that includes a blur radius specification.</p></div><div class="div3">
-<h4><a name="feature-textOutline-unblurred" id="feature-textOutline-unblurred"/>D.1.90 #textOutline-unblurred</h4><p>A TTML transformation processor supports the
-<code>#textOutline-unblurred</code> feature if it recognizes and is capable of
-transforming values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that does not include a blur radius specification.</p><p>A TTML presentation processor supports the
-<code>#textOutline-unblurred</code> feature if it implements presentation semantic support
-for values of the <a href="#style-attribute-textOutline"><code>tts:textOutline</code></a>
-attribute that does not include a blur radius specification.</p></div><div class="div3">
-<h4><a name="feature-tickRate" id="feature-tickRate"/>D.1.91 #tickRate</h4><p>A TTML transformation processor supports the
-<code>#tickRate</code> feature if it recognizes and is capable of
-transforming the <a href="#parameter-attribute-tickRate"><code>ttp:tickRate</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#tickRate</code> feature if it implements presentation semantic support
-for the <a href="#parameter-attribute-tickRate"><code>ttp:tickRate</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-timeBase-clock" id="feature-timeBase-clock"/>D.1.92 #timeBase-clock</h4><p>A TTML transformation processor supports the
-<code>#timeBase-clock</code> feature if it recognizes and is capable
-of transforming the <code>clock</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-clockMode"><code>#clockMode</code></a> feature.</p><p>A TTML presentation processor supports the
-<code>#timeBase-clock</code> feature if it implements presentation
-semantic support for the <code>clock</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-clockMode"><code>#clockMode</code></a> feature.</p></div><div class="div3">
-<h4><a name="feature-timeBase-media" id="feature-timeBase-media"/>D.1.93 #timeBase-media</h4><p>A TTML transformation processor supports the
-<code>#timeBase-media</code> feature if it recognizes and is capable
-of transforming the <code>media</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#timeBase-media</code> feature if it implements presentation
-semantic support for the <code>media</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-timeBase-smpte" id="feature-timeBase-smpte"/>D.1.94 #timeBase-smpte</h4><p>A TTML transformation processor supports the
-<code>#timeBase-smpte</code> feature if it recognizes and is capable
-of transforming the <code>smpte</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-dropMode"><code>#dropMode</code></a> feature.</p><p>A TTML presentation processor supports the
-<code>#timeBase-smpte</code> feature if it implements presentation
-semantic support for the <code>smpte</code> value of the <a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a>
-attribute and if it supports the <a href="#feature-dropMode"><code>#dropMode</code></a> feature.</p></div><div class="div3">
-<h4><a name="feature-timeContainer" id="feature-timeContainer"/>D.1.95 #timeContainer</h4><p>A TTML transformation processor supports the
-<code>#timeContainer</code> feature if it recognizes and is capable of
-transforming the <a href="#timing-attribute-timeContainer"><code>timeContainer</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#timeContainer</code> feature if it implements presentation semantic support
-for the <a href="#timing-attribute-timeContainer"><code>timeContainer</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-time-clock" id="feature-time-clock"/>D.1.96 #time-clock</h4><p>A TTML transformation processor supports the
-<code>#time-clock</code> feature if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : hours ":" minutes ":" seconds ( fraction )?
-</pre></div><p>A TTML presentation processor supports the
-<code>#time-clock</code> feature if it implements presentation
-semantic support for the same syntax specified above.</p></div><div class="div3">
-<h4><a name="feature-time-clock-with-frames" id="feature-time-clock-with-frames"/>D.1.97 #time-clock-with-frames</h4><p>A TTML transformation processor supports the
-<code>#time-clock-with-frames</code> feature if it supports the
-<a href="#feature-frameRate"><code>#frameRate</code></a>,
-<a href="#feature-frameRateMultiplier"><code>#frameRateMultiplier</code></a>, and
-<a href="#feature-subFrameRate"><code>#subFrameRate</code></a> features
-and if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : hours ":" minutes ":" seconds ( fraction | ":" frames ( "." sub-frames )? )?
-</pre></div><p>A TTML presentation processor supports the
-<code>#time-clock-with-frames</code> feature if it implements
-presentation semantic support for the same features and syntax
-specified above.</p></div><div class="div3">
-<h4><a name="feature-time-offset" id="feature-time-offset"/>D.1.98 #time-offset</h4><p>A TTML transformation processor supports the
-<code>#time-offset</code> feature if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : time-count fraction? ( "h" | "m" | "s" | "ms" )
-</pre></div><p>A TTML presentation processor supports the
-<code>#time-offset</code> feature if it implements presentation
-semantic support for the same syntax specified above.</p></div><div class="div3">
-<h4><a name="feature-time-offset-with-frames" id="feature-time-offset-with-frames"/>D.1.99 #time-offset-with-frames</h4><p>A TTML transformation processor supports the
-<code>#time-offset-with-frames</code> feature if it supports the
-<a href="#feature-frameRate"><code>#frameRate</code></a>,
-<a href="#feature-frameRateMultiplier"><code>#frameRateMultiplier</code></a>, and
-<a href="#feature-subFrameRate"><code>#subFrameRate</code></a> features
-and if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : time-count fraction? "f"
-</pre></div><p>A TTML presentation processor supports the
-<code>#time-offset-with-frames</code> feature if it implements
-presentation semantic support for the same features and syntax
-specified above.</p></div><div class="div3">
-<h4><a name="feature-time-offset-with-ticks" id="feature-time-offset-with-ticks"/>D.1.100 #time-offset-with-ticks</h4><p>A TTML transformation processor supports the
-<code>#time-offset-with-ticks</code> feature if it supports the 
-<a href="#feature-tickRate"><code>#tickRate</code></a> feature
-and if it recognizes and is capable of
-transforming all values of the <a href="#timing-value-timeExpression">&lt;timeExpression&gt;</a> that
-satisfy the following subset of time expression syntax:</p><div class="exampleInner"><pre>
-&lt;timeExpression&gt;
-  : time-count fraction? "t"
-</pre></div><p>A TTML presentation processor supports the
-<code>#time-offset-with-ticks</code> feature if it implements presentation
-semantic support for the same features and syntax specified above.</p></div><div class="div3">
-<h4><a name="feature-timing" id="feature-timing"/>D.1.101 #timing</h4><p>A TTML transformation processor supports the <code>#timing</code>
-feature if it recognizes and is capable of transforming the following
-vocabulary defined by <a href="#timing"><b>10 Timing</b></a>:</p><ul><li><p><a href="#timing-attribute-begin">@<code>begin</code></a></p></li><li><p><a href="#timing-attribute-dur">@<code>dur</code></a></p></li><li><p><a href="#timing-attribute-end">@<code>end</code></a></p></li></ul><p>A TTML presentation processor supports the <code>#timing</code>
-feature if it implements presentation semantic support for the
-same vocabulary enumerated above.</p></div><div class="div3">
-<h4><a name="feature-transformation" id="feature-transformation"/>D.1.102 #transformation</h4><p>A TTML processor supports the
-<code>#transformation</code> feature if it
-(1) satisfies the generic processor criteria defined by 
-<a href="#conformance-generic-processor"><b>3.2.1 Generic Processor Conformance</b></a> and
-(2) implements the transformation semantics of the following features:</p><ul><li><p><a href="#content"><code>#content</code></a></p></li><li><p><a href="#feature-core"><code>#core</code></a></p></li><li><p><a href="#feature-profile"><code>#profile</code></a></p></li><li><p><a href="#feature-structure"><code>#structure</code></a></p></li><li><p><a href="#feature-time-offset"><code>#time-offset</code></a></p></li><li><p><a href="#timing"><code>#timing</code></a></p></li></ul></div><div class="div3">
-<h4><a name="feature-unicodeBidi" id="feature-unicodeBidi"/>D.1.103 #unicodeBidi</h4><p>A TTML transformation processor supports the
-<code>#unicodeBidi</code> feature if it recognizes and is capable of
-transforming all defined values of the <a href="#style-attribute-unicodeBidi"><code>tts:unicodeBidi</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#unicodeBidi</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-unicodeBidi"><code>tts:unicodeBidi</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-visibility" id="feature-visibility"/>D.1.104 #visibility</h4><p>A TTML transformation processor supports the
-<code>#visibility</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#visibility</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-visibility-block" id="feature-visibility-block"/>D.1.105 #visibility-block</h4><p>A TTML transformation processor supports the
-<code>#visibility-block</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that would generate a
-block area during presentation processing.</p><p>A TTML presentation processor supports the
-<code>#visibility-block</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that generates a
-block area.</p></div><div class="div3">
-<h4><a name="feature-visibility-inline" id="feature-visibility-inline"/>D.1.106 #visibility-inline</h4><p>A TTML transformation processor supports the
-<code>#visibility-inline</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that would generate an
-inline area during presentation processing.</p><p>A TTML presentation processor supports the
-<code>#visibility-inline</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a content element that generates an
-inline area.</p></div><div class="div3">
-<h4><a name="feature-visibility-region" id="feature-visibility-region"/>D.1.107 #visibility-region</h4><p>A TTML transformation processor supports the
-<code>#visibility-region</code> feature if it recognizes and is
-capable of transforming all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p><p>A TTML presentation processor supports the
-<code>#visibility-region</code> feature if it implements presentation semantic
-support for all defined values of the <a href="#style-attribute-visibility"><code>tts:visibility</code></a>
-attribute when applied to a <a href="#layout-vocabulary-region"><code>region</code></a> element.</p></div><div class="div3">
-<h4><a name="feature-wrapOption" id="feature-wrapOption"/>D.1.108 #wrapOption</h4><p>A TTML transformation processor supports the
-<code>#wrapOption</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-wrapOption"><code>tts:wrapOption</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#wrapOption</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-wrapOption"><code>tts:wrapOption</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-writingMode" id="feature-writingMode"/>D.1.109 #writingMode</h4><p>A TTML transformation processor supports the
-<code>#writingMode</code> feature if it recognizes and is capable
-of transforming all defined values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#writingMode</code> feature if it implements presentation semantic support
-for all defined values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-writingMode-vertical" id="feature-writingMode-vertical"/>D.1.110 #writingMode-vertical</h4><p>A TTML transformation processor supports the
-<code>#writingMode-vertical</code> feature if it recognizes and is
-capable of transforming the <code>tbrl</code>, <code>tblr</code>, and
-<code>tb</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#writingMode-vertical</code> feature if it implements presentation semantic
-support for the <code>tbrl</code>, <code>tblr</code>, and
-<code>tb</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-writingMode-horizontal" id="feature-writingMode-horizontal"/>D.1.111 #writingMode-horizontal</h4><p>A TTML transformation processor supports the
-<code>#writingMode-horizontal</code> feature if it recognizes and is
-capable of transforming the <code>lrtb</code>, <code>rltb</code>,
-<code>lr</code> and <code>rl</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#writingMode-horizontal</code> feature if it implements presentation semantic
-support for the <code>lrtb</code>, <code>rltb</code>, <code>lr</code>
-and <code>rl</code> values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-writingMode-horizontal-lr" id="feature-writingMode-horizontal-lr"/>D.1.112 #writingMode-horizontal-lr</h4><p>A TTML transformation processor supports the
-<code>#writingMode-horizontal</code> feature if it recognizes and is
-capable of transforming the <code>lrtb</code> and <code>lr</code>
-values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#writingMode-horizontal-lr</code> feature if it implements presentation semantic
-support for the <code>lrtb</code> and <code>lr</code> values of the
-<a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-writingMode-horizontal-rl" id="feature-writingMode-horizontal-rl"/>D.1.113 #writingMode-horizontal-rl</h4><p>A TTML transformation processor supports the
-<code>#writingMode-horizontal</code> feature if it recognizes and is
-capable of transforming the <code>rltb</code> and <code>rl</code>
-values of the <a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#writingMode-horizontal-rl</code> feature if it implements presentation semantic
-support for the <code>rltb</code> and <code>rl</code> values of the
-<a href="#style-attribute-writingMode"><code>tts:writingMode</code></a>
-attribute.</p></div><div class="div3">
-<h4><a name="feature-zIndex" id="feature-zIndex"/>D.1.114 #zIndex</h4><p>A TTML transformation processor supports the
-<code>#zIndex</code> feature if it recognizes and is capable of
-transforming the <a href="#style-attribute-zIndex"><code>tts:zIndex</code></a>
-attribute.</p><p>A TTML presentation processor supports the
-<code>#zIndex</code> feature if it implements presentation semantic support for
-the <a href="#style-attribute-zIndex"><code>tts:zIndex</code></a>
-attribute.</p></div></div><div class="div2">
-<h3><a name="feature-support" id="feature-support"/>D.2 Feature Support</h3><p>The following table, <a href="#feature-support-table"><b>Table E-1 – Feature Support</b></a>,
-enumerates every defined feature designation (expressed without the TT
-Feature Namespace), and, for each designated feature, specifies
-whether the feature is mandatory (M) or optional (O) for
-transformation and presentation processors.</p><table summary="HTML Table" id="feature-support-table" class="common"><caption>Table E-1 – Feature Support</caption><col width="60%" span="1"/><col width="20%" span="1"/><col width="20%" span="1"/><tbody><tr><td><span class="strong">Feature</span></td><td><span class="strong">Transformation</span></td><td><span class="strong">Presentation</span></td></tr><tr><td><a href="#feature-animation"><code>#animation</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor"><code>#backgroundColor</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor-block"><code>#backgroundColor-block</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor-inline"><code>#backgroundColor-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-backgroundColor-region"><code>#backgroundColor-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-bidi"><code>#bidi</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-cellResolution"><code>#cellResolution</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode"><code>#clockMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode-gps"><code>#clockMode-gps</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode-local"><code>#clockMode-local</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-clockMode-utc"><code>#clockMode-utc</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-color"><code>#color</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-content"><code>#content</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-core"><code>#core</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-direction"><code>#direction</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display"><code>#display</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display-block"><code>#display-block</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display-inline"><code>#display-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-display-region"><code>#display-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-displayAlign"><code>#displayAlign</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode"><code>#dropMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode-dropNTSC"><code>#dropMode-dropNTSC</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode-dropPAL"><code>#dropMode-dropPAL</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-dropMode-nonDrop"><code>#dropMode-nonDrop</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-extent"><code>#extent</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-extent-region"><code>#extent-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-extent-root"><code>#extent-root</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontFamily"><code>#fontFamily</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontFamily-generic"><code>#fontFamily-generic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontFamily-non-generic"><code>#fontFamily-non-generic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontSize"><code>#fontSize</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontSize-anamorphic"><code>#fontSize-anamorphic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontSize-isomorphic"><code>#fontSize-isomorphic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontStyle"><code>#fontStyle</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontStyle-italic"><code>#fontStyle-italic</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontStyle-oblique"><code>#fontStyle-oblique</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontWeight"><code>#fontWeight</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-fontWeight-bold"><code>#fontWeight-bold</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-frameRate"><code>#frameRate</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-frameRateMultiplier"><code>#frameRateMultiplier</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-layout"><code>#layout</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length"><code>#length</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-cell"><code>#length-cell</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-em"><code>#length-em</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-integer"><code>#length-integer</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-negative"><code>#length-negative</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-percentage"><code>#length-percentage</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-pixel"><code>#length-pixel</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-positive"><code>#length-positive</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-length-real"><code>#length-real</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-lineBreak-uax14"><code>#lineBreak-uax14</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-lineHeight"><code>#lineHeight</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-markerMode"><code>#markerMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-markerMode-continuous"><code>#markerMode-continuous</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-markerMode-discontinuous"><code>#markerMode-discontinuous</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-metadata"><code>#metadata</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-nested-div"><code>#nested-div</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-nested-span"><code>#nested-span</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-opacity"><code>#opacity</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-origin"><code>#origin</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-overflow"><code>#overflow</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-overflow-visible"><code>#overflow-visible</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding"><code>#padding</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-1"><code>#padding-1</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-2"><code>#padding-2</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-3"><code>#padding-3</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-padding-4"><code>#padding-4</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-pixelAspectRatio"><code>#pixelAspectRatio</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-presentation"><code>#presentation</code></a></td><td>O</td><td>M</td></tr><tr><td><a href="#feature-profile"><code>#profile</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-showBackground"><code>#showBackground</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-structure"><code>#structure</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-styling"><code>#styling</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-chained"><code>#styling-chained</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-inheritance-content"><code>#styling-inheritance-content</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-inheritance-region"><code>#styling-inheritance-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-inline"><code>#styling-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-nested"><code>#styling-nested</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-styling-referential"><code>#styling-referential</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-subFrameRate"><code>#subFrameRate</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textAlign"><code>#textAlign</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textAlign-absolute"><code>#textAlign-absolute</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textAlign-relative"><code>#textAlign-relative</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration"><code>#textDecoration</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration-over"><code>#textDecoration-over</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration-through"><code>#textDecoration-through</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textDecoration-under"><code>#textDecoration-under</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOutline"><code>#textOutline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOutline-blurred"><code>#textOutline-blurred</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-textOutline-unblurred"><code>#textOutline-unblurred</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-tickRate"><code>#tickRate</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeBase-clock"><code>#timeBase-clock</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeBase-media"><code>#timeBase-media</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeBase-smpte"><code>#timeBase-smpte</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timeContainer"><code>#timeContainer</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-clock"><code>#time-clock</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-clock-with-frames"><code>#time-clock-with-frames</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-offset"><code>#time-offset</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-time-offset-with-frames"><code>#time-offset-with-frames</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-time-offset-with-ticks"><code>#time-offset-with-ticks</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-timing"><code>#timing</code></a></td><td>M</td><td>M</td></tr><tr><td><a href="#feature-transformation"><code>#transformation</code></a></td><td>M</td><td>O</td></tr><tr><td><a href="#feature-unicodeBidi"><code>#unicodeBidi</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility"><code>#visibility</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility-block"><code>#visibility-block</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility-inline"><code>#visibility-inline</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-visibility-region"><code>#visibility-region</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-wrapOption"><code>#wrapOption</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode"><code>#writingMode</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-vertical"><code>#writingMode-vertical</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-horizontal"><code>#writingMode-horizontal</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-horizontal-lr"><code>#writingMode-horizontal-lr</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-writingMode-horizontal-rl"><code>#writingMode-horizontal-rl</code></a></td><td>O</td><td>O</td></tr><tr><td><a href="#feature-zIndex"><code>#zIndex</code></a></td><td>O</td><td>O</td></tr></tbody></table><p>For the sake of convenience, the following table,
-<a href="#feature-transformation-mandatory-table"><b>Table E-2 – Mandatory Features - Transformation</b></a>, enumerates all
-mandatory features for a TTML Transformation Processor, providing additional
-comments to summarize the context of usage or the nature of the feature.
-The TTML Profile Definition Document that defines the corresponding
-DFXP Transformation Profile is specified in
-<a href="#profile-dfxp-transformation"><b>F.1 DFXP Transformation Profile</b></a>.
-</p><table summary="HTML Table" id="feature-transformation-mandatory-table" class="common"><caption>Table E-2 – Mandatory Features - Transformation</caption><col width="60%" span="1"/><col width="40%" span="1"/><tbody><tr><td><span class="strong">Feature</span></td><td><span class="strong">Comments</span></td></tr><tr><td><a href="#feature-content"><code>#content</code></a></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>,
-<a href="#content-vocabulary-br"><code>br</code></a>
-</td></tr><tr><td><a href="#feature-core"><code>#core</code></a></td><td>
-<a href="#content-attribute-id">@<code>xml:id</code></a>,
-<a href="#content-attribute-id">@<code>xml:lang</code></a>,
-<a href="#content-attribute-id">@<code>xml:space</code></a>
-</td></tr><tr><td><a href="#feature-profile"><code>#profile</code></a></td><td/></tr><tr><td><a href="#feature-structure"><code>#structure</code></a></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</code></a>,
-<a href="#document-structure-vocabulary-head"><code>head</code></a>
-</td></tr><tr><td><a href="#feature-time-offset"><code>#time-offset</code></a></td><td/></tr><tr><td><a href="#feature-timing"><code>#timing</code></a></td><td>
-<a href="#timing-attribute-begin">@<code>begin</code></a>,
-<a href="#timing-attribute-dur">@<code>dur</code></a>,
-<a href="#timing-attribute-end">@<code>end</code></a>
-</td></tr><tr><td><a href="#feature-transformation"><code>#transformation</code></a></td><td/></tr></tbody></table><p>For the sake of convenience, the following table,
-<a href="#feature-presentation-mandatory-table"><b>Table E-3 – Mandatory Features - Presentation</b></a>, enumerates all
-mandatory features for a TTML Presentation Processor, providing additional
-comments to summarize the context of usage or the nature of the feature.
-The TTML Profile Definition Document that defines the corresponding
-DFXP Presentation Profile is specified in
-<a href="#profile-dfxp-presentation"><b>F.2 DFXP Presentation Profile</b></a>.
-</p><table summary="HTML Table" id="feature-presentation-mandatory-table" class="common"><caption>Table E-3 – Mandatory Features - Presentation</caption><col width="60%" span="1"/><col width="40%" span="1"/><tbody><tr><td><span class="strong">Feature</span></td><td><span class="strong">Comments</span></td></tr><tr><td><a href="#feature-content"><code>#content</code></a></td><td>
-<a href="#document-structure-vocabulary-body"><code>body</code></a>,
-<a href="#content-vocabulary-div"><code>div</code></a>,
-<a href="#content-vocabulary-p"><code>p</code></a>,
-<a href="#content-vocabulary-span"><code>span</code></a>,
-<a href="#content-vocabulary-br"><code>br</code></a>
-</td></tr><tr><td><a href="#feature-core"><code>#core</code></a></td><td>
-<a href="#content-attribute-id">@<code>xml:id</code></a>,
-<a href="#content-attribute-id">@<code>xml:lang</code></a>,
-<a href="#content-attribute-id">@<code>xml:space</code></a>
-</td></tr><tr><td><a href="#feature-profile"><code>#profile</code></a></td><td/></tr><tr><td><a href="#feature-presentation"><code>#presentation</code></a></td><td/></tr><tr><td><a href="#feature-structure"><code>#structure</code></a></td><td>
-<a href="#document-structure-vocabulary-tt"><code>tt</code></a>,
-<a href="#document-structure-vocabulary-head"><code>head</code></a>
-</td></tr><tr><td><a href="#feature-time-offset"><code>#time-offset</code></a></td><td/></tr><tr><td><a href="#feature-timing"><code>#timing</code></a></td><td>
-<a href="#timing-attribute-begin">@<code>begin</code></a>,
-<a href="#timing-attribute-dur">@<code>dur</code></a>,
-<a href="#timing-attribute-end">@<code>end</code></a>
-</td></tr></tbody></table></div></div><div class="div1">
-<h2><a name="extensions" id="extensions"/>E Extensions</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the syntactic form of extension designations, which are
-used to express authorial intent regarding the support for extension
-mechanisms in a TTML processor.</p><div class="div2">
-<h3><a name="extension-designations" id="extension-designations"/>E.1 Extension Designations</h3><p>An extension designation is expressed as a string that adheres to the following
-form:</p><div class="exampleInner"><pre>
-extension-designation
-  : extension-namespace designation
-
-extension-namespace
-  : <em>TT Extension Namespace</em>                  // http://www.w3.org/ns/ttml/extension/
-  | <em>Other Extension Namespace</em>               // expressed as an absolute URI
-
-designation
-  : "#" token-char+
-
-token-char
-  : { XML NameChar }                        // XML 1.1 Production [4a]
-</pre></div><p>If the extension namespace of an extension designation is the TT
-Extension Namespace, then all values of the following
-<code>designation</code> token are reserved for future
-standardization.</p><p>If the extension namespace of an extension designation is not the
-TT Extension Namespace, i.e., is an <em>Other Extension Namespace</em>,
-then the extension namespace must be expressed as an absolute URI
-capable of serving as a base URI used in combination with a
-<code>designation</code> token that takes the form of a fragment
-identifier.</p></div></div><div class="div1">
-<h2><a name="profiles" id="profiles"/>F Profiles</h2><p><em>This appendix is normative.</em></p><p>This appendix specifies the following standard TTML profiles:</p><ul><li><p><a href="#profile-dfxp-transformation"><b>F.1 DFXP Transformation Profile</b></a></p></li><li><p><a href="#profile-dfxp-presentation"><b>F.2 DFXP Presentation Profile</b></a></p></li><li><p><a href="#profile-dfxp-full"><b>F.3 DFXP Full Profile</b></a></p></li></ul><p>Each TTML profile is defined in terms of a TTML Profile Definition Document,
-which is expressed as an XML document wherein the root element adheres to
-<a href="#parameter-vocabulary-profile"><b>6.1.1 ttp:profile</b></a>.</p><div class="div2">
-<h3><a name="profile-dfxp-transformation" id="profile-dfxp-transformation"/>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;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;!-- required (mandatory) feature support --&gt;
-    &lt;feature value="required"&gt;#content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#core&lt;/feature&gt;
-    &lt;feature value="required"&gt;#profile&lt;/feature&gt;
-    &lt;feature value="required"&gt;#structure&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timing&lt;/feature&gt;
-    &lt;feature value="required"&gt;#transformation&lt;/feature&gt;
-    &lt;!-- optional (voluntary) feature support --&gt;
-    &lt;feature value="optional"&gt;#animation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#bidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#cellResolution&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-gps&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-local&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-utc&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#color&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#direction&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#displayAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropNTSC&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropPAL&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-nonDrop&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-root&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-non-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-anamorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-isomorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-italic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-oblique&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight-bold&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRateMultiplier&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#layout&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-cell&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-em&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-integer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-negative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-percentage&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-pixel&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-positive&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-real&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineBreak-uax14&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineHeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-continuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-discontinuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#metadata&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-div&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-span&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#opacity&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#origin&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow-visible&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-1&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-2&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-3&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-4&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#pixelAspectRatio&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#presentation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#showBackground&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-chained&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-content&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-nested&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-referential&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#subFrameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-absolute&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-relative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-over&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-through&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-under&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-blurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-unblurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#tickRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-ticks&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-media&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-smpte&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeContainer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#unicodeBidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#wrapOption&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-lr&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-rl&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-vertical&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#zIndex&lt;/feature&gt;
-  &lt;/features&gt;
-  &lt;extensions xml:base="http://www.w3.org/ns/ttml/extension/"&gt;
-    &lt;!-- required (mandatory) extension support --&gt;
-    &lt;!-- optional (voluntary) extension support --&gt;
-  &lt;/extensions&gt;
-&lt;/profile&gt;
-
-</pre></div></div><div class="div2">
-<h3><a name="profile-dfxp-presentation" id="profile-dfxp-presentation"/>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;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;!-- required (mandatory) feature support --&gt;
-    &lt;feature value="required"&gt;#content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#core&lt;/feature&gt;
-    &lt;feature value="required"&gt;#presentation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#profile&lt;/feature&gt;
-    &lt;feature value="required"&gt;#structure&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timing&lt;/feature&gt;
-    &lt;!-- optional (voluntary) feature support --&gt;
-    &lt;feature value="optional"&gt;#animation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#backgroundColor&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#bidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#cellResolution&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-gps&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-local&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode-utc&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#clockMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#color&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#direction&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#display&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#displayAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropNTSC&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-dropPAL&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode-nonDrop&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#dropMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent-root&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#extent&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily-non-generic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontFamily&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-anamorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize-isomorphic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontSize&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-italic&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle-oblique&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontStyle&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight-bold&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#fontWeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#frameRateMultiplier&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#layout&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-cell&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-em&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-integer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-negative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-percentage&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-pixel&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-positive&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length-real&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#length&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineBreak-uax14&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#lineHeight&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-continuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode-discontinuous&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#markerMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#metadata&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-div&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#nested-span&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#opacity&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#origin&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow-visible&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#overflow&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-1&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-2&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-3&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding-4&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#padding&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#pixelAspectRatio&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#showBackground&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-chained&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-content&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inheritance-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-nested&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling-referential&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#styling&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#subFrameRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-absolute&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign-relative&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textAlign&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-over&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-through&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration-under&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textDecoration&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-blurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline-unblurred&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#textOutline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#tickRate&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-frames&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#time-offset-with-ticks&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-clock&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-media&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeBase-smpte&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#timeContainer&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#transformation&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#unicodeBidi&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-block&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-inline&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility-region&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#visibility&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#wrapOption&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-lr&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal-rl&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-horizontal&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode-vertical&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#writingMode&lt;/feature&gt;
-    &lt;feature value="optional"&gt;#zIndex&lt;/feature&gt;
-  &lt;/features&gt;
-  &lt;extensions xml:base="http://www.w3.org/ns/ttml/extension/"&gt;
-    &lt;!-- required (mandatory) extension support --&gt;
-    &lt;!-- optional (voluntary) extension support --&gt;
-  &lt;/extensions&gt;
-&lt;/profile&gt;
-
-</pre></div></div><div class="div2">
-<h3><a name="profile-dfxp-full" id="profile-dfxp-full"/>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;profile xmlns="http://www.w3.org/ns/ttml#parameter"&gt;
-  &lt;features xml:base="http://www.w3.org/ns/ttml/feature/"&gt;
-    &lt;!-- required (mandatory) feature support --&gt;
-    &lt;feature value="required"&gt;#animation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor-block&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#backgroundColor&lt;/feature&gt;
-    &lt;feature value="required"&gt;#bidi&lt;/feature&gt;
-    &lt;feature value="required"&gt;#cellResolution&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode-gps&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode-local&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode-utc&lt;/feature&gt;
-    &lt;feature value="required"&gt;#clockMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#color&lt;/feature&gt;
-    &lt;feature value="required"&gt;#content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#core&lt;/feature&gt;
-    &lt;feature value="required"&gt;#direction&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display-block&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#display&lt;/feature&gt;
-    &lt;feature value="required"&gt;#displayAlign&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode-dropNTSC&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode-dropPAL&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode-nonDrop&lt;/feature&gt;
-    &lt;feature value="required"&gt;#dropMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#extent-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#extent-root&lt;/feature&gt;
-    &lt;feature value="required"&gt;#extent&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontFamily-generic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontFamily-non-generic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontFamily&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontSize-anamorphic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontSize-isomorphic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontSize&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontStyle-italic&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontStyle-oblique&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontStyle&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontWeight-bold&lt;/feature&gt;
-    &lt;feature value="required"&gt;#fontWeight&lt;/feature&gt;
-    &lt;feature value="required"&gt;#frameRate&lt;/feature&gt;
-    &lt;feature value="required"&gt;#frameRateMultiplier&lt;/feature&gt;
-    &lt;feature value="required"&gt;#layout&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-cell&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-em&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-integer&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-negative&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-percentage&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-pixel&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-positive&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length-real&lt;/feature&gt;
-    &lt;feature value="required"&gt;#length&lt;/feature&gt;
-    &lt;feature value="required"&gt;#lineBreak-uax14&lt;/feature&gt;
-    &lt;feature value="required"&gt;#lineHeight&lt;/feature&gt;
-    &lt;feature value="required"&gt;#markerMode-continuous&lt;/feature&gt;
-    &lt;feature value="required"&gt;#markerMode-discontinuous&lt;/feature&gt;
-    &lt;feature value="required"&gt;#markerMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#metadata&lt;/feature&gt;
-    &lt;feature value="required"&gt;#nested-div&lt;/feature&gt;
-    &lt;feature value="required"&gt;#nested-span&lt;/feature&gt;
-    &lt;feature value="required"&gt;#opacity&lt;/feature&gt;
-    &lt;feature value="required"&gt;#origin&lt;/feature&gt;
-    &lt;feature value="required"&gt;#overflow-visible&lt;/feature&gt;
-    &lt;feature value="required"&gt;#overflow&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-1&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-2&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-3&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding-4&lt;/feature&gt;
-    &lt;feature value="required"&gt;#padding&lt;/feature&gt;
-    &lt;feature value="required"&gt;#pixelAspectRatio&lt;/feature&gt;
-    &lt;feature value="required"&gt;#presentation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#profile&lt;/feature&gt;
-    &lt;feature value="required"&gt;#showBackground&lt;/feature&gt;
-    &lt;feature value="required"&gt;#structure&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-chained&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-inheritance-content&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-inheritance-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-nested&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling-referential&lt;/feature&gt;
-    &lt;feature value="required"&gt;#styling&lt;/feature&gt;
-    &lt;feature value="required"&gt;#subFrameRate&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textAlign-absolute&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textAlign-relative&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textAlign&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration-over&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration-through&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration-under&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textDecoration&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOutline-blurred&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOutline-unblurred&lt;/feature&gt;
-    &lt;feature value="required"&gt;#textOutline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#tickRate&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-clock-with-frames&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-clock&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset-with-frames&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset-with-ticks&lt;/feature&gt;
-    &lt;feature value="required"&gt;#time-offset&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeBase-clock&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeBase-media&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeBase-smpte&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timeContainer&lt;/feature&gt;
-    &lt;feature value="required"&gt;#timing&lt;/feature&gt;
-    &lt;feature value="required"&gt;#transformation&lt;/feature&gt;
-    &lt;feature value="required"&gt;#unicodeBidi&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility-block&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility-inline&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility-region&lt;/feature&gt;
-    &lt;feature value="required"&gt;#visibility&lt;/feature&gt;
-    &lt;feature value="required"&gt;#wrapOption&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-horizontal-lr&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-horizontal-rl&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-horizontal&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode-vertical&lt;/feature&gt;
-    &lt;feature value="required"&gt;#writingMode&lt;/feature&gt;
-    &lt;feature value="required"&gt;#zIndex&lt;/feature&gt;
-    &lt;!-- optional (voluntary) feature support --&gt;
-  &lt;/features&gt;
-  &lt;extensions xml:base="http://www.w3.org/ns/ttml/extension/"&gt;
-    &lt;!-- required (mandatory) extension support --&gt;
-    &lt;!-- optional (voluntary) extension support --&gt;
-  &lt;/extensions&gt;
-&lt;/profile&gt;
-
-</pre></div></div></div><div class="div1">
-<h2><a name="references" id="references"/>G References</h2><p><em>This appendix is normative.</em></p><dl><dt class="label"><a name="css2" id="css2"/>CSS2</dt><dd>Bert Bos et al.,
-<a href="http://www.w3.org/TR/1998/REC-CSS2-19980512/"><cite>Cascading
-Style Sheets, Level 2</cite></a>, W3C Recommendation, 12
-May 1998. (See
-<a href="http://www.w3.org/TR/1998/REC-CSS2-19980512/">http://www.w3.org/TR/1998/REC-CSS2-19980512/</a>.)
-</dd><dt class="label"><a name="gps" id="gps"/>GPS</dt><dd>
-<a href="http://tycho.usno.navy.mil/gpsinfo.html"><cite>Global
-Positioning System</cite></a>, US Naval Observatory.
-(See
-<a href="http://tycho.usno.navy.mil/gpsinfo.html">http://tycho.usno.navy.mil/gpsinfo.html</a>.)
-</dd><dt class="label"><a name="mime-media" id="mime-media"/>MIME</dt><dd>Ned Freed and Nathaniel Borenstein,  
-<a href="http://www.rfc-editor.org/rfc/rfc2046.txt"><cite>Multipurpose Internet
-Mail Extensions (MIME) Part Two: Media Types</cite></a>,
-RFC 2046, November 1996, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc2046.txt">http://www.rfc-editor.org/rfc/rfc2046.txt</a>.)
-</dd><dt class="label"><a name="rng" id="rng"/>RELAX NG</dt><dd>ISO/IEC 19757-2,
-<a href="http://www.iso.org/"><cite>Information technology – Document
-Schema Definition Language (DSDL) – Part 2: Regular-grammar-based validation – RELAX NG</cite></a>,
-International Organization for Standardization (ISO).
-</dd><dt class="label"><a name="smil21" id="smil21"/>SMIL 2.1</dt><dd>Dick Bultermann, et al.,
-<a href="http://www.w3.org/TR/2005/REC-SMIL2-20051213/"><cite>Synchronized
-Multimedia Integration Language (SMIL 2.1)</cite></a>,
-W3C Recommendation, 13 December 2005. (See
-<a href="http://www.w3.org/TR/2005/REC-SMIL2-20051213/">http://www.w3.org/TR/2005/REC-SMIL2-20051213/</a>.)
-</dd><dt class="label"><a name="smpte12m" id="smpte12m"/>SMPTE 12M</dt><dd>ANSI/SMPTE 12M,
-<a href="http://www.smpte.org/"><cite>Television, Audio and Film –
-Time and Control Code</cite></a>, SMPTE Standard.
-</dd><dt class="label"><a name="srgb" id="srgb"/>SRGB</dt><dd>IEC 61966-2-1,
-<a href="http://www.iec.ch/"><cite>Multimedia
-systems and equipment – Colour measurement and management
-– Part 2-1: Colour management – Default RGB colour space
-– sRGB</cite></a>, International Electrotechnical
-Commission (IEC).
-</dd><dt class="label"><a name="uaag" id="uaag"/>UAAG</dt><dd>Ian Jacobs, Jon Gunderson, and Eric Hansen, Eds.,
-<a href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/"><cite>User
-Agent Accessibility Guidelines 1.0</cite></a>, W3C Recommendation, 17
-December 2002. (See
-<a href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/">http://www.w3.org/TR/2002/REC-UAAG10-20021217/</a>.)
-</dd><dt class="label"><a name="utc" id="utc"/>UTC</dt><dd>
-Recommendation TF.460,
-<a href="http://www.itu.int/"><cite>Standard-Frequency and Time-Signal
-Emissions</cite></a>, International
-Telecommunciations Union, Radio Sector (ITU-R).
-</dd><dt class="label"><a name="uax14" id="uax14"/>UAX14</dt><dd>Asmus Freytag, <a href="http://www.unicode.org/reports/tr14/tr14-17.html"><cite>Line Breaking
-Properties</cite></a>, Unicode Consortium, 29 August 2005. (See
-<a href="http://www.unicode.org/reports/tr14/tr14-17.html">http://www.unicode.org/reports/tr14/tr14-17.html</a>.)
-</dd><dt class="label"><a name="wcag" id="wcag"/>WCAG</dt><dd>Ben Caldwell, et al., Eds.,
-<a href="http://www.w3.org/TR/2008/REC-WCAG20-20081211/"><cite>Web
-Content Accessibility Guidelines (WCAG) 2.0</cite></a>, W3C Recommendation, 11 December 2008. (See
-<a href="http://www.w3.org/TR/2008/REC-WCAG20-20081211/">http://www.w3.org/TR/2008/REC-WCAG20-20081211/</a>.)
-</dd><dt class="label"><a name="xml10" id="xml10"/>XML 1.0</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/2008/REC-xml-20081126/"><cite>Extensible Markup Language (XML)
-1.0 (Fifth Edition)</cite></a>, W3C Recommendation, 26 November 2008. (See
-<a href="http://www.w3.org/TR/2008/REC-xml-20081126/">http://www.w3.org/TR/2008/REC-xml-20081126/</a>.)
-</dd><dt class="label"><a name="xml11" id="xml11"/>XML 1.1</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/2006/REC-xml11-20060816/"><cite>Extensible Markup Language (XML)
-1.1 (Second Edition)</cite></a>, W3C Recommendation, 16 August 2006, edited in place 29 September 2006. (See
-<a href="http://www.w3.org/TR/2006/REC-xml11-20060816/">http://www.w3.org/TR/2006/REC-xml11-20060816/</a>.)
-</dd><dt class="label"><a name="xmlbase" id="xmlbase"/>XML Base</dt><dd>Jonathan Marsh and Richard Tobin, Eds.,
-<a href="http://www.w3.org/TR/2009/REC-xmlbase-20090128/"><cite>XML Base (Second Edition)</cite></a>,
-W3C Recommendation, 28 January 2009. (See
-<a href="http://www.w3.org/TR/2009/REC-xmlbase-20090128/">http://www.w3.org/TR/2009/REC-xmlbase-20090128/</a>.)
-</dd><dt class="label"><a name="xmlid" id="xmlid"/>XML ID</dt><dd>Jonathan Marsh, Daniel Veillard, Norman Walsh, Eds.,
-<a href="http://www.w3.org/TR/2005/REC-xml-id-20050909/"><cite>xml:id Version 1.0</cite></a>,
-W3C Recommendation, 09 September 2005. (See
-<a href="http://www.w3.org/TR/2005/REC-xml-id-20050909/">http://www.w3.org/TR/2005/REC-xml-id-20050909/</a>.)
-</dd><dt class="label"><a name="xml-media" id="xml-media"/>XML Media</dt><dd>Makato Murata, Simon St. Laurent,
-Kan Khon, Eds., <a href="http://www.rfc-editor.org/rfc/rfc3023.txt"><cite>XML Media Types</cite></a>,
-RFC 3023, January 2001, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc3023.txt">http://www.rfc-editor.org/rfc/rfc3023.txt</a>.)
-</dd><dt class="label"><a name="infoset" id="infoset"/>XML InfoSet</dt><dd>John Cowan and Richard Tobin, Eds.,
-<a href="http://www.w3.org/TR/2004/REC-xml-infoset-20040204/"><cite>XML Information Set (Second Edition)</cite></a>,
-W3C Recommendation, 04 February 2004. (See
-<a href="http://www.w3.org/TR/2004/REC-xml-infoset-20040204/">http://www.w3.org/TR/2004/REC-xml-infoset-20040204/</a>.)
-</dd><dt class="label"><a name="rfc3023" id="rfc3023"/>XML Media Types</dt><dd>Makato Murata, et al.,
-<a href="http://www.rfc-editor.org/rfc/rfc3023.txt"><cite>XML Media Types</cite></a>,
-RFC 3023, January 2001, IETF.(See
-<a href="http://www.rfc-editor.org/rfc/rfc3023.txt">http://www.rfc-editor.org/rfc/rfc3023.txt</a>.)
-</dd><dt class="label"><a name="xmlns10" id="xmlns10"/>XML Namespaces 1.0</dt><dd>Tim Bray, et al.
-<a href="http://www.w3.org/TR/2009/REC-xml-names-20091208/"><cite>Namespaces
-in XML 1.0 (Third Edition)</cite></a>, W3C Recommendation, 8 December 2009. (See
-<a href="http://www.w3.org/TR/2009/REC-xml-names-20091208/">http://www.w3.org/TR/2009/REC-xml-names-20091208/</a>.)
-</dd><dt class="label"><a name="xsd-1" id="xsd-1"/>XML Schema Part 1</dt><dd>Henry S. Thompson, David Beech,
-Murray Maloney, Noah Mendelsohn, Eds.,
-<a href="http://www.w3.org/TR/xmlschema-1/"><cite>XML Schema Part 1: Structures</cite></a>,
-W3C Recommendation, 28 October 2004. (See
-<a href="http://www.w3.org/TR/xmlschema-1/">http://www.w3.org/TR/xmlschema-1/</a>.)
-</dd><dt class="label"><a name="xsd-2" id="xsd-2"/>XML Schema Part 2</dt><dd>Paul Biron and Ashok Malhotra,
-<a href="http://www.w3.org/TR/xmlschema-2/"><cite>XML Schema Part 2: Datatypes</cite></a>,
-W3C Recommendation, 28 October 2004. (See
-<a href="http://www.w3.org/TR/xmlschema-2/">http://www.w3.org/TR/xmlschema-2/</a>.)
-</dd><dt class="label"><a name="xsl11" id="xsl11"/>XSL 1.1</dt><dd>Anders Berglund,
-<a href="http://www.w3.org/TR/2006/REC-xsl11-20061205/"><cite>Extensible Stylesheet Language (XSL) Version 1.1</cite></a>,
-W3C Recommendation, 05 December 2006. (See
-<a href="http://www.w3.org/TR/2006/REC-xsl11-20061205/">http://www.w3.org/TR/2006/REC-xsl11-20061205/</a>.)
-</dd></dl></div><div class="div1">
-<h2><a name="other-references" id="other-references"/>H Other References (Non-Normative)</h2><dl><dt class="label"><a name="ccreq" id="ccreq"/>CC-DECODER-REQ</dt><dd><a href="http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr15.119.htm"><cite>Closed Caption Decoder
-Requirements for Analog Television</cite></a>,
-United States Code of Federal Regulations, Title 47, Volume 1, Part 15, § 15.119. (See
-<a href="http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr15.119.htm">http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr15.119.htm</a>.)
-</dd><dt class="label"><a name="cea608c" id="cea608c"/>CEA-608-C</dt><dd>
-EIA/CEA-608-C,
-<a href="http://www.ce.org/"><cite>Line 21 Data
-Services</cite></a>, EIA/CEA Standard,
-Consumer Electronics Association (CEA).
-</dd><dt class="label"><a name="css3-color" id="css3-color"/>CSS3 Color</dt><dd>Tantek Çelik and Chris Lilley,
-<a href="http://www.w3.org/TR/2003/CR-css3-color-20030514/"><cite>CSS3 Color
-Module</cite></a>, W3C Candidate Recommendation, 14 May 2003. (See
-<a href="http://www.w3.org/TR/2003/CR-css3-color-20030514/">http://www.w3.org/TR/2003/CR-css3-color-20030514/</a>.)
-</dd><dt class="label"><a name="dcmes" id="dcmes"/>DCMES 1.1</dt><dd>Dublin Core Metadata Initiative,
-<a href="http://dublincore.org/documents/dces/"><cite>Dublin Core Metadata Element Set, Version 1.1: Reference Description</cite></a>. (See
-<a href="http://dublincore.org/documents/dces/">http://dublincore.org/documents/dces/</a>.)
-</dd><dt class="label"><a name="mpeg7-5" id="mpeg7-5"/>MPEG7-5</dt><dd>
-ISO/IEC 15938-5,
-<a href="http://www.iso.org/"><cite>Information technology – Multimedia content description
-interface – Part 5: Multimedia description schemes</cite></a>,
-International Organization for Standardization (ISO).
-</dd><dt class="label"><a name="nsstate" id="nsstate"/>NSState</dt><dd>Norman Walsh, Ed.,
-<a href="http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09.html"><cite>The Disposition
-of Names in an XML Namespace</cite></a>, TAG Finding, 9 January 2006. (See
-<a href="http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09.html">http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09</a>.)
-</dd><dt class="label"><a name="qaf-sg" id="qaf-sg"/>QAF SG</dt><dd>Karl Dubost, et al.,
-<a href="http://www.w3.org/TR/2005/REC-qaframe-spec-20050817/"><cite>QA
-Framework: Specifications Guidelines</cite></a>, W3C Recommendation, 17
-August 2005. (See
-<a href="http://www.w3.org/TR/qaframe-spec/">http://www.w3.org/TR/qaframe-spec/</a>.)
-</dd><dt class="label"><a name="smpte170m" id="smpte170m"/>SMPTE 170M</dt><dd>ANSI/SMPTE 170M, 
-<a href="http://www.smpte.org/"><cite>Television – Composite Analog Video
-Signal – NTSC for Studio Applications</cite></a>, SMPTE Standard.
-</dd><dt class="label"><a name="svg11" id="svg11"/>SVG 1.1</dt><dd>Jon Ferraiolo, Jun Fujisawa, Dean Jackson, Eds.,
-<a href="http://www.w3.org/TR/2003/REC-SVG11-20030114/"><cite>Scalable
-Vector Graphics (SVG) 1.1 Specification</cite></a>, W3C Recommendation, 14
-January 2003. (See
-<a href="http://www.w3.org/TR/2003/REC-SVG11-20030114/">http://www.w3.org/TR/2003/REC-SVG11-20030114/</a>.)
-</dd><dt class="label"><a name="ttaf1-req" id="ttaf1-req"/>TTAF1-REQ</dt><dd>Glenn Adams, Ed.,
-<a href="http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/"><cite>Timed Text (TT) Authoring Format 1.0 Use
-Cases and Requirements</cite></a>,
-W3C Working Group Note, 27 April 2006. (See
-<a href="http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/">http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/</a>.)
-</dd><dt class="label"><a name="xhtml10" id="xhtml10"/>XHTML 1.0</dt><dd>Steven Pemberton, et al.,
-<a href="http://www.w3.org/TR/2002/REC-xhtml1-20020801/"><cite>XHTML™ 1.0,
-The Extensible Hypertext Markup Language (Second Edition)</cite></a>,
-W3C Recommendation, 01
-August 2002. (See
-<a href="http://www.w3.org/TR/2002/REC-xhtml1-20020801/">http://www.w3.org/TR/2002/REC-xhtml1-20020801/</a>.)
-</dd></dl></div><div class="div1">
-<h2><a name="requirements" id="requirements"/>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
-<a href="#ttaf1-req">[TTAF1-REQ]</a>. The following table enumerates these requirements and
-indicates the extent to which they are satisfied by this specification, where
-<em>S</em> denotes a requirement is satisfied, <em>P</em> denotes
-a requirement is partially satisfied, and <em>N</em> denotes a
-requirement is not satisfied.</p><table summary="HTML Table" id="requirements-table" class="common"><caption>Table J-1 – Requirement Satisfaction</caption><col width="10%" span="1"/><col width="40%" span="1"/><col width="10%" span="1"/><tbody><tr><th>ID</th><th>Name</th><th>Status</th><th>Comments</th></tr><tr><td>R100</td><td>Specification Format</td><td>S</td><td/></tr><tr><td>R101</td><td>Specification Modularity</td><td>S</td><td/></tr><tr><td>R102</td><td>Specification Organization</td><td>S</td><td/></tr><tr><td>R103</td><td>Core and Periphery</td><td>S</td><td>TT extension namespaces</td></tr><tr><td>R104</td><td>Evolution of Core</td><td>S</td><td>TT extension namespaces</td></tr><tr><td>R105</td><td>Ownership of Core</td><td>S</td><td>TT namespaces</td></tr><tr><td>R106</td><td>Surjection of Core</td><td>S</td><td/></tr><tr><td>R107</td><td>Evolution of Periphery</td><td>S</td><td>TT extension namespaces</td></tr><tr><td>R108</td><td>Ownership of Periphery</td><td>S</td><td>Non-TT namespaces</td></tr><tr><td>R109</td><td>Transformation</td><td>S</td><td>Supports 3GPP, QText, RealText, SAMI</td></tr><tr><td>R110</td><td>Streamable Transformation</td><td>S</td><td>Progressive decoding</td></tr><tr><td>R111</td><td>Accessibility – Content</td><td>S</td><td>Alternative document instances</td></tr><tr><td>R112</td><td>Accessibility – Authoring System</td><td>S</td><td/></tr><tr><td>R200</td><td>Authorability</td><td>S</td><td/></tr><tr><td>R201</td><td>Multiple Natural Languages</td><td>S</td><td>Alternative document instances</td></tr><tr><td>R202</td><td>Natural Language Coverage</td><td>S</td><td>Unicode 4.0</td></tr><tr><td>R203</td><td>Natural Language Association Granularity</td><td>S</td><td>See <code>xml:lang</code></td></tr><tr><td>R204</td><td>Minimum Character Representability</td><td>S</td><td>Unicode 4.0</td></tr><tr><td>R205</td><td>Intrinsic and Extrinsic Text Content</td><td>P</td><td>Intrinsic only</td></tr><tr><td>R206</td><td>Markup Association</td><td>P</td><td>Intrinsic only</td></tr><tr><td>R207</td><td>Conditional Content</td><td>N</td><td/></tr><tr><td>R208</td><td>Flowed Text</td><td>S</td><td/></tr><tr><td>R209</td><td>Logical Flowed Text Vocabulary</td><td>S</td><td/></tr><tr><td>R210</td><td>Presentational Flowed Text Vocabulary</td><td>S</td><td>Implied mapping from logical flowed text.</td></tr><tr><td>R211</td><td>Flowed Text Vocabulary Relationship</td><td>S</td><td/></tr><tr><td>R212</td><td>Flowed Text Vocabulary Separation</td><td>N</td><td/></tr><tr><td>R213</td><td>Non-Flowed Text</td><td>N</td><td/></tr><tr><td>R214</td><td>Non-Flowed Text Vocabulary</td><td>N</td><td/></tr><tr><td>R215</td><td>Hybrid Flowed and Non-Flowed Text</td><td>N</td><td/></tr><tr><td>R216</td><td>Hyperlinking</td><td>N</td><td>Can support via XLink</td></tr><tr><td>R217</td><td>Embedded Graphics</td><td>N</td><td/></tr><tr><td>R218</td><td>Non-Embedded Graphics</td><td>N</td><td/></tr><tr><td>R219</td><td>Embedded Fonts</td><td>N</td><td/></tr><tr><td>R220</td><td>Non-Embedded Fonts</td><td>N</td><td/></tr><tr><td>R221</td><td>Descriptive Vocabulary</td><td>S</td><td>See <code>ttm:agent</code>, <code>ttm:role</code></td></tr><tr><td>R222</td><td>Embedded Audio</td><td>N</td><td/></tr><tr><td>R223</td><td>Non-Embedded Audio</td><td>N</td><td/></tr><tr><td>R290</td><td>Markup Format</td><td>S</td><td/></tr><tr><td>R291</td><td>Markup Format and Unicode Interaction</td><td>S</td><td/></tr><tr><td>R292</td><td>Extrinsic Resource References</td><td>N</td><td>No extrinsic references</td></tr><tr><td>R293</td><td>Schema Validity Specification</td><td>S</td><td/></tr><tr><td>R300</td><td>Inline Styling</td><td>S</td><td/></tr><tr><td>R301</td><td>Inline Styling Form</td><td>P</td><td>Inline and referential styling</td></tr><tr><td>R301</td><td>Out-of-Line Styling</td><td>N</td><td/></tr><tr><td>R301</td><td>Out-of-Line Styling Form</td><td>N</td><td/></tr><tr><td>R304</td><td>Styling Prioritization</td><td>S</td><td/></tr><tr><td>R305</td><td>Style Parameters – Aural</td><td>N</td><td/></tr><tr><td>R306</td><td>Style Parameters – Visual</td><td>P</td><td>Supports absolute position, background color, color, display none, display alignment,
-font family, font size, font style, font weight, height, line height, origin,
-opacity, overflow, padding (before, after, start, end), text alignment,
-text shadow (as outline), visibility, width, writing mode, z-index</td></tr><tr><td>R390</td><td>Style Parameter Symmetry</td><td>S</td><td/></tr><tr><td>R391</td><td>Style Parameter Definitions</td><td>S</td><td/></tr><tr><td>R392</td><td>Style Parameter Shorthands</td><td>S</td><td/></tr><tr><td>R401</td><td>Inline Timing</td><td>S</td><td/></tr><tr><td>R402</td><td>Out-of-Line Timing</td><td>N</td><td/></tr><tr><td>R403</td><td>Synchronization Parameters</td><td>P</td><td>Supports begin, end, dur</td></tr><tr><td>R404</td><td>Synchronization Parameter Value Spaces</td><td>P</td><td>Supports offset values, media marker values (SMPTE 12M), wallclock values</td></tr><tr><td>R405</td><td>Time Containment Semantics</td><td>P</td><td>Supports sequential, parallel</td></tr><tr><td>R500</td><td>Animation Modes</td><td>P</td><td>Supports discrete</td></tr><tr><td>R502</td><td>Highlight Animation</td><td>S</td><td><code>&lt;set tts:backgroundColor="..."/&gt;</code></td></tr><tr><td>R503</td><td>Fade Transition Animation</td><td>S</td><td><code>&lt;set tts:opacity="..."/&gt;</code></td></tr><tr><td>R504</td><td>Animated Style Parameters – Aural</td><td>N</td><td/></tr><tr><td>R505</td><td>Animated Style Parameters – Visual</td><td>P</td><td>Supports animating background color, color, display, opacity, origin, visibility</td></tr><tr><td>N506</td><td>Animated Content</td><td>S</td><td/></tr><tr><td>R600</td><td>Metadata Item Association</td><td>S</td><td>See <code>metadata</code>, <code>Metadata.class</code></td></tr><tr><td>R601</td><td>Metadata Item Constituents</td><td>P</td><td>Supports name, value</td></tr><tr><td>R602</td><td>Metadata Item Value Representation</td><td>P</td><td>See <code>metadata</code></td></tr><tr><td>R603</td><td>Metadata Item Extensibility</td><td>S</td><td>See <code>metadata</code></td></tr><tr><td>R604</td><td>Metadata Item Validation</td><td>S</td><td>See <code>metadata</code></td></tr><tr><td>R690</td><td>Dublin Core Preference</td><td>N</td><td>Uses <code>ttm:copyright</code>, <code>ttm:desc</code>, <code>ttm:title</code></td></tr></tbody></table></div><div class="div1">
-<h2><a 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="d3e17042" id="d3e17042"/>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
-the model (if a model is indicated);
-the fourth column specifies details about the derivation; the last
-column refers to additional notes describing the nature of the
-derivation.</p><p>In the fourth column, which describes details of derivation, a
-notation is use to indicate the addition or removal of an attribute.
-For example, in the derivation of the <code>tt:div</code> element, the
-details column includes "-@class", which denotes that the
-<code>class</code> attribute that is specified for use with the
-<code>xhtml:div</code> model element is not specified for use with the
-corresponding TTML element; in contrast, the details column includes
-"+@begin", which denotes that a <code>begin</code> attribute is added
-that is not specified for use with the <code>xhtml:div</code> model
-element.</p><table summary="HTML Table" id="element-vocab-derivation-table" class="common"><caption>Table K-1 – Elements</caption><col width="20%" span="1"/><col width="17%" span="1"/><col width="13%" align="center" span="1"/><col width="40%" span="1"/><col width="10%" align="center" span="1"/><tbody><tr><td><span class="strong">Element</span></td><td><span class="strong">Model</span></td><td><span class="strong">Reference</span></td><td><span class="strong">Details</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="#document-structure-vocabulary-body"><code>tt:body</code></a></td><td><code>xhtml:body</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*; content model
-subsetted to zero or more division (div) children, and supersetted by
-optional metadata and animation children</td><td>1,2</td></tr><tr><td><a href="#content-vocabulary-br"><code>tt:br</code></a></td><td><code>xhtml:br</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@title; +@ttm:*, +@tts:*, +@xml:lang, +@xml:space;
-content model supersetted by
-optional metadata and animation children for congruity with other
-content vocabulary</td><td>1,2</td></tr><tr><td><a href="#content-vocabulary-div"><code>tt:div</code></a></td><td><code>xhtml:div</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*, +@xml:space; content model
-subsetted to zero or more paragraph (p) children, and supersetted by
-optional metadata and animation children</td><td>1,2,3</td></tr><tr><td><a href="#document-structure-vocabulary-head"><code>tt:head</code></a></td><td><code>xhtml:head</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@dir, -@lang, -@profile; +@id, +@xml:space; content model changed to
-optional metadata children, followed by optional styling child,
-followed by optional layout child</td><td>1,3</td></tr><tr><td><a href="#layout-vocabulary-layout"><code>tt:layout</code></a></td><td><code>fo:simple-page-master</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-metadata"><code>tt:metadata</code></a></td><td><code>svg:metadata</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@xml:base; +@ttm:*, +@xml:lang, +@xml:space; content model
-subsetted to foreign namespace element content only (no #PCDATA)</td><td>3,5</td></tr><tr><td><a href="#content-vocabulary-p"><code>tt:p</code></a></td><td><code>xhtml:p</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*, +@xml:space; content model
-subsetted to zero or more span children, and supersetted by optional
-metadata and animation children</td><td>1,2,3</td></tr><tr><td><a href="#layout-vocabulary-region"><code>tt:region</code></a></td><td><code>fo:region-*</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#animation-vocabulary-set"><code>tt:set</code></a></td><td><code>svg:set</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@* except begin, dur, end; +@tts:*, +@xml:lang, +@xml:space</td><td>3,6</td></tr><tr><td><a href="#content-vocabulary-span"><code>tt:span</code></a></td><td><code>xhtml:span</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@class, -@dir, -@lang, -@on*, -@title; +@begin, +@dur, +@end, +@region,
-+@timeContainer, +@ttm:*, +@tts:*, +@xml:space; content model
-subsetted to zero or more #PCDATA or break (br) children, and
-supersetted by optional metadata and animation children</td><td>1,2,3</td></tr><tr><td><a href="#styling-vocabulary-style"><code>tt:style</code></a></td><td><em>style specification</em></td><td><a href="#css2">[CSS2]</a></td><td>XML representation of identified set of pairs of style property
-name and value, with optional inclusion of other styles by reference
-to other style elements</td><td>7</td></tr><tr><td><a href="#styling-vocabulary-styling"><code>tt:styling</code></a></td><td><code>xhtml:style</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>XML representation of a set of style specifications sets, each
-represented by a style child element</td><td>1,7</td></tr><tr><td><a href="#document-structure-vocabulary-tt"><code>tt:tt</code></a></td><td><code>xhtml:html</code></td><td><a href="#xhtml10">[XHTML 1.0]</a></td><td>-@dir, -@lang; +@id, +@ttp:*, +@xml:space; content model subsetted by
-permitting body and/or head to be optional</td><td>1,8</td></tr><tr><td><a href="#metadata-vocabulary-actor"><code>ttm:actor</code></a></td><td><code>mpeg7:Creator</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-agent"><code>ttm:agent</code></a></td><td><code>mpeg7:Agent</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-copyright"><code>ttm:copyright</code></a></td><td><code>mpeg7:CopyrightString</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-desc"><code>ttm:desc</code></a></td><td><code>svg:desc</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@class, -@style, -@xml:base</td><td>2,5,9</td></tr><tr><td><a href="#metadata-vocabulary-name"><code>ttm:name</code></a></td><td><code>mpeg7:Name</code></td><td><a href="#mpeg7-5">[MPEG7-5]</a></td><td>conceptual derivation</td><td>4</td></tr><tr><td><a href="#metadata-vocabulary-title"><code>ttm:title</code></a></td><td><code>svg:title</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>-@class, -@style, -@xml:base</td><td>2,5,9</td></tr><tr><td><a href="#parameter-vocabulary-extension"><code>ttp:extension</code></a></td><td><code>@requiredExtensions</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#parameter-vocabulary-extensions"><code>ttp:extensions</code></a></td><td><code>@requiredExtensions</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#parameter-vocabulary-feature"><code>ttp:feature</code></a></td><td><code>@requiredFeatures</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#parameter-vocabulary-features"><code>ttp:features</code></a></td><td><code>@requiredFeatures</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>10</td></tr><tr><td><a href="#parameter-vocabulary-profile"><code>ttp:profile</code></a></td><td><code>@baseProfile</code></td><td><a href="#svg11">[SVG 1.1]</a></td><td>conceptual derivation</td><td>11</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>Derivation is indicated with respect to the strict DTD defined
-by <a href="#xhtml10">[XHTML 1.0]</a>, §A.1.</p></li><li><p>The <code>class</code> attribute is effectively replaced by the
-<code>style</code>
-attribute, which, instead of specifying an inline style,
-refers indirectly to one or more <a href="#styling-vocabulary-style"><code>style</code></a>
-elements that define a set of style specification sets.</p></li><li><p>The <code>xml:lang</code> and <code>xml:space</code> attributes are defined for all element
-types in order to support their inheritance semantics to operate in
-the context of foreign namespace elements.</p></li><li><p>Derivation is conceptual (notional) only.</p></li><li><p>The <code>xml:base</code> attribute is not used since there are no external
-references from core vocabulary.</p></li><li><p>The <code>attributeName</code> and <code>to</code> attributes of
-<code>svg:set</code> are replaced by the
-direct expression of the target attribute name and value by use of a
-<code>tts:*</code> attribute.</p></li><li><p>CSS style specification syntax is mapped to XML by use of
-attributes defined in the TT Style Namespace.</p></li><li><p>The <code>xml:id</code> attribute is defined for use on all element types.</p></li><li><p>The <code>style</code> attribute is supported only on content
-elements.</p></li><li><p>Derived from the use of <code>@requiredExtensions</code>
-and <code>@requiredFeatures</code> on the <code>svg:svg</code> element,
-but extended to support distinct specification of optionality.</p></li><li><p>Derived from the use of <code>@baseProfile</code>
-and <code>@version</code> on the <code>svg:svg</code> element.</p></li></ol></div></div><div class="div2">
-<h3><a name="d3e17521" id="d3e17521"/>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
-the model (if a model is indicated);
-the fourth column specifies details about the derivation; the last
-column refers to additional notes describing the nature of the
-derivation.</p><p>In the fourth column, which describes details of derivation, a
-notation is use to indicate the addition or removal of an attribute
-value.  For example, in the derivation of the <code>timeContainer</code>
-attribute,
-the details column includes "-excl", which denotes that the
-<code>excl</code> value that is specified for use with the
-<code>timeContainer</code> model attribute is not specified for use with the
-corresponding TTML attribute; similarly, an "+<em>value</em>"
-in the details column indicates that the attribute's values have been
-extended to include <em>value</em>.</p><p>Only those attributes that are specified for use on more than one TTML
-element type are listed below. Those per-element namespace attributes
-that are uniquely defined for a specific TTML element type are not
-listed below, but are considered to be part of the specific element
-type's derivation described in <a href="#element-vocab-derivation-table"><b>Table K-1 – Elements</b></a>
-above.</p><table summary="HTML Table" id="attribute-vocab-derivation-table" class="common"><caption>Table K-2 – Attributes</caption><col width="20%" span="1"/><col width="17%" span="1"/><col width="13%" align="center" span="1"/><col width="40%" span="1"/><col width="10%" align="center" span="1"/><tbody><tr><td><span class="strong">Attribute</span></td><td><span class="strong">Model</span></td><td><span class="strong">Reference</span></td><td><span class="strong">Details</span></td><td><span class="strong">Notes</span></td></tr><tr><td><a href="#timing-attribute-begin"><code>begin</code></a></td><td><code>begin</code></td><td><a href="#smil21">[SMIL 2.1]</a></td><td>see notes</td><td>2,3,4</td></tr><tr><td><a href="#timing-attribute-dur"><code>dur</code></a></td><td><code>dur</code></td><td><a href="#smil21">[SMIL 2.1]</a></td><td>see notes</td><td>2,3,4</td></tr><tr><td><a href="#timing-attribute-end"><code>end</code></a></td><td><code>end</code></td><td><a href="#smil21">[SMIL 2.1]</a></td><td>see notes</td><td>2,3,4</td></tr><tr><td><a href="#layout-attribute-region"><code>region</code></a></td><td><code>master-reference</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>conceptual derivation</td><td/></tr><tr><td><a href="#style-attribute-style"><code>style</code></a></td><td><code>class</code></td><td><a href="#css2">[CSS2]</a></td><td>dereferences style specification(s) directly</td><td/></tr><tr><td><a href="#timing-attribute-timeContainer"><code>timeContainer</code></a></td><td><code>timeContainer</code></td><td><a href="#smil21">[SMIL 2.1]</a></td><td>-excl, -none; no default attribute value</td><td>5</td></tr><tr><td><a href="#metadata-attribute-agent"><code>ttm:agent</code></a></td><td><em>none</em></td><td/><td>used to attribute agent of content</td><td/></tr><tr><td><a href="#metadata-attribute-role"><code>ttm:role</code></a></td><td><em>none</em></td><td/><td>used to attribute role of content</td><td/></tr><tr><td><a href="#parameter-attribute-cellResolution"><code>ttp:cellResolution</code></a></td><td><em>none</em></td><td/><td>expresses uniform grid resolution for cell based coordinates</td><td/></tr><tr><td><a href="#parameter-attribute-clockMode"><code>ttp:clockMode</code></a></td><td><em>none</em></td><td/><td>determines how to interpret time expressions</td><td/></tr><tr><td><a href="#parameter-attribute-frameRate"><code>ttp:frameRate</code></a></td><td><em>none</em></td><td/><td>expresses integral frame rate</td><td/></tr><tr><td><a href="#parameter-attribute-frameRateMultiplier"><code>ttp:frameRateMultiplier</code></a></td><td><em>none</em></td><td/><td>used to express non-integral, rational frame rates</td><td/></tr><tr><td><a href="#parameter-attribute-markerMode"><code>ttp:markerMode</code></a></td><td><em>none</em></td><td/><td>expresses marker continuity semantics</td><td/></tr><tr><td><a href="#parameter-attribute-pixelAspectRatio"><code>ttp:pixelAspectRatio</code></a></td><td><em>none</em></td><td/><td>expresses pixel aspect ratio of related media</td><td/></tr><tr><td><a href="#parameter-attribute-profile"><code>ttp:profile</code></a></td><td><em>none</em></td><td/><td>expresses profile of TTML used by document instance</td><td/></tr><tr><td><a href="#parameter-attribute-dropMode"><code>ttp:dropMode</code></a></td><td><em>none</em></td><td/><td>expresses frame counting (drop) modes</td><td/></tr><tr><td><a href="#parameter-attribute-subFrameRate"><code>ttp:subFrameRate</code></a></td><td><em>none</em></td><td/><td>expresses sub-frame rate</td><td/></tr><tr><td><a href="#parameter-attribute-tickRate"><code>ttp:tickRate</code></a></td><td><em>none</em></td><td/><td>used to interpret tick based time expressions</td><td/></tr><tr><td><a href="#parameter-attribute-timeBase"><code>ttp:timeBase</code></a></td><td><em>none</em></td><td/><td>used to interpret semantics of time expressions</td><td/></tr><tr><td><a href="#style-attribute-backgroundColor"><code>tts:backgroundColor</code></a></td><td><code>background-color</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1,6</td></tr><tr><td><a href="#style-attribute-color"><code>tts:color</code></a></td><td><code>color</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>6</td></tr><tr><td><a href="#style-attribute-direction"><code>tts:direction</code></a></td><td><code>direction</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td/></tr><tr><td><a href="#style-attribute-display"><code>tts:display</code></a></td><td><code>display</code></td><td><a href="#css2">[CSS2]</a></td><td>only <code>auto</code>, <code>none</code></td><td/></tr><tr><td><a href="#style-attribute-displayAlign"><code>tts:displayAlign</code></a></td><td><code>display-align</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-extent"><code>tts:extent</code></a></td><td><code>width</code>, <code>height</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>shorthand property</td><td/></tr><tr><td><a href="#style-attribute-fontFamily"><code>tts:fontFamily</code></a></td><td><code>font-family</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code>, extends generic family names</td><td>1</td></tr><tr><td><a href="#style-attribute-fontSize"><code>tts:fontSize</code></a></td><td><code>font-size</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1,7</td></tr><tr><td><a href="#style-attribute-fontWeight"><code>tts:fontWeight</code></a></td><td><code>font-weight</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code>, <code>-bolder</code>, <code>-lighter</code>, <code>-&lt;number&gt;</code></td><td>1</td></tr><tr><td><a href="#style-attribute-lineHeight"><code>tts:lineHeight</code></a></td><td><code>line-height</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code>, <code>-&lt;number&gt;</code>, <code>-&lt;space&gt;</code></td><td>1</td></tr><tr><td><a href="#style-attribute-opacity"><code>tts:opacity</code></a></td><td><code>opacity</code></td><td><a href="#css3-color">[CSS3 Color]</a></td><td><code>-inherit</code></td><td/></tr><tr><td><a href="#style-attribute-origin"><code>tts:origin</code></a></td><td><code>top</code>, <code>left</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td>shorthand property</td><td/></tr><tr><td><a href="#style-attribute-overflow"><code>tts:overflow</code></a></td><td><code>overflow</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code>, <code>-auto</code>, <code>-error-if-overflow</code>;</td><td>8</td></tr><tr><td><a href="#style-attribute-padding"><code>tts:padding</code></a></td><td><code>padding</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>9</td></tr><tr><td><a href="#style-attribute-showBackground"><code>tts:showBackground</code></a></td><td><code>showBackground</code></td><td><a href="#smil21">[SMIL 2.1]</a></td><td><code>-inherit</code></td><td/></tr><tr><td><a href="#style-attribute-textAlign"><code>tts:textAlign</code></a></td><td><code>text-align</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-textDecoration"><code>tts:textDecoration</code></a></td><td><code>text-decoration</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1,10,13</td></tr><tr><td><a href="#style-attribute-textOutline"><code>tts:textOutline</code></a></td><td><code>text-shadow</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>11,13</td></tr><tr><td><a href="#style-attribute-unicodeBidi"><code>tts:unicodeBidi</code></a></td><td><code>unicode-bidi</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-visibility"><code>tts:visibility</code></a></td><td><code>visibility</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code>, <code>-collapse</code></td><td/></tr><tr><td><a href="#style-attribute-wrapOption"><code>tts:wrapOption</code></a></td><td><code>wrap-option</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1</td></tr><tr><td><a href="#style-attribute-writingMode"><code>tts:writingMode</code></a></td><td><code>writing-mode</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code>, <code>+tblr</code></td><td>1</td></tr><tr><td><a href="#style-attribute-zIndex"><code>tts:zIndex</code></a></td><td><code>z-index</code></td><td><a href="#xsl11">[XSL 1.1]</a></td><td><code>-inherit</code></td><td>1</td></tr><tr><td><a href="#content-attribute-id"><code>xml:id</code></a></td><td><code>xml:id</code></td><td><a href="#xmlid">[XML ID]</a></td><td>complies with model</td><td/></tr><tr><td><a href="#content-attribute-lang"><code>xml:lang</code></a></td><td><code>xml:lang</code></td><td><a href="#xml10">[XML 1.0]</a></td><td>complies with model</td><td/></tr><tr><td><a href="#content-attribute-space"><code>xml:space</code></a></td><td><code>xml:space</code></td><td><a href="#xml10">[XML 1.0]</a></td><td>see notes</td><td>12</td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><ol class="enumar"><li><p>Attribute name and/or value(s) are normalized to use
-<em>lowerCamelCase</em> naming convention.</p></li><li><p>Restricted to expressing a clock value that denotes one of the
-following in accordance to whether the parameter expressed by the
-<code>ttp:timeBase</code> attribute is <code>media</code>, <code>smpte</code>,
-or <code>clock</code>, respectively:
-(1) an offset from an implicit syncbase that is linked to a media time
-line, (2) an event time
-that represents the occurrence of an implicit media marker, or (3) a wallclock
-time.</p></li><li><p>Syntactically subsets and supersets the <a href="#smil21">[SMIL 2.1]</a> <code>Clock-value</code> syntax as follows:
-(1) requires non-negative <code>Full-clock-value</code> or
-<code>Timecount-value</code>;
-(2) if <code>Full-clock-value</code>
-then <em>hours</em> must be two or more digits;
-(3) if <code>Timecount-value</code>, then <em>metric</em> must be
-specified;
-(4) uses <code>m</code> as alias for <code>min</code> metric to denote
-minutes;
-(5) adds <code>f</code> and <code>t</code> metrics denoting frames and
-ticks, respectively;
-(6) adds alternative expression of optional <code>Fraction</code> in
-<code>Full-clock-value</code> by specifying frame count or frame
-count with subframe count.
-</p></li><li><p>
-Interpretation of time expression is further constrained by
-parameters expressed by
-<code>ttp:clockMode</code>,
-<code>ttp:dropMode</code>,
-<code>ttp:frameRate</code>,
-<code>ttp:frameRateMultiplier</code>,
-<code>ttp:markerMode</code>,
-<code>ttp:subFrameRate</code>,
-<code>ttp:tickRate</code>, and
-<code>ttp:timeBase</code> attributes.</p></li><li><p>Uses subset of named colors from model to which two aliases are
-added as follows: <code>magenta</code> as <code>fuchsia</code>, and <code>cyan</code>
-as <code>aqua</code>.</p></li><li><p>If not specified, then parallel (par) container semantics apply to
-the element types specified by <a href="#timing-attribute-timeContainer"><b>10.2.4 timeContainer</b></a>.</p></li><li><p>Restricts size to length specification which can be a percentage;
-adds optional second length (or percentage) for
-specifying separate horizontal and vertical scaling of glyph's EM
-square.</p></li><li><p>Expressed in terms of writing mode relative padding properties
-rather than absolute padding properties.</p></li><li><p>Excludes <code>blink</code> and <code>no-blink</code> values.</p></li><li><p>Uses only one length specification instead of two, where one length
-defines distance of outline effect from nominal edge of glyph contour
-outline perpendicular to point of glyph contour. Percentage lengths
-are also added to express outline effect in relative to font size.
-Outline effects are intended to be drawn both outside of outer closed
-contours and inside of inner closed contours.</p></li><li><p>On root element, default attribute value specified as
-<code>default</code>, which is defined in terms of whitespace
-normalization. Semantics of preservation and default normalization are
-defined in terms of presentation semantics by <a href="#content-attribute-space"><b>7.2.3 xml:space</b></a>.</p></li><li><p>Defined to be inheritable.</p></li></ol></div></div></div><div class="div1">
-<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="d3e18389" id="d3e18389"/>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="d3e18553" id="d3e18553"/>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">
-<h2><a name="streaming" id="streaming"/>L Streaming TTML Content (Non-Normative)</h2><p>TTML Content is designed to support streamability by implementing the
-following properties:</p><ul><li><p>can be progressively encoded (i.e., does not require computing
-subsequent data prior to sending current data);</p></li><li><p>can be progressively decoded (i.e., does not require forward
-references, but uses only reverse references when necessary);</p></li><li><p>does not require dereferencing (and subsequent loading) of any
-resources other than TTML content (i.e., no embedded URIs);</p></li><li><p>does not support alternative content forms (e.g., different
-language, graphics formats, time bases) in a single document;</p></li><li><p>has timing structure compiled into inline format that makes
-possible a temporal ordering of content that follows temporal
-presentation order;</p></li><li><p>constrains content models to prevent arbitrary nested content
-structures;</p></li></ul><p>One possible means by which TTML Content may be streamed is to
-partition a TTML document instance's information set into
-non-overlapping fragments, where one particular fragment, call it the
-<em>root fragment</em>, represents the front matter (head) of the
-document instance as well as its top level structural elements, and
-other fragments represent content whose time intervals are expected to
-be active in parallel.</p><p>In applications that require arbitrary (random) entry into a
-stream, i.e., the property of being able to start reading data at an
-arbitrary data access unit, the root fragment will be repetitively
-transmitted (inserted) into the stream in order to permit a decoder to
-resynchronize and acquire sufficient structural information in the
-information set in order to interpret subsequent content
-fragments.</p><p>An example of such a fragmentation of a TTML document instance is
-shown in <a href="#fragment-streaming-graphic"><b>Figure 3 – Fragment Streaming</b></a>.</p><table summary="HTML Table" id="fragment-streaming-graphic" class="example-images"><caption>Figure 3 – Fragment Streaming</caption><tbody><tr><td><img src="images/streaming.png" alt="Fragment Streaming"/></td></tr></tbody></table><div class="note"><p class="prefix"><b>Note:</b></p><p>This specification does not define a transport buffer model or a decoder
-capabilities model.</p></div></div><div class="div1">
-<h2><a name="acknowledgments" id="acknowledgments"/>M Acknowledgments (Non-Normative)</h2><p>The editor acknowledges the members of the Timed Text Working
-Group, the members of other W3C Working Groups, and industry experts
-in other forums who have contributed directly or indirectly to the
-process or content of creating this document.</p><p>The current and former members of the Timed Text Working Group are:
-Glenn Adams (Samsung Electronics Co., Ltd.), John Birch (Invited expert), Kees Blom (CWI), Dick Bulterman (CWI), Frans de Jong (Invited expert), Mike Dolan (W3C Invited Experts), Geoff Freed (WGBH National Center for Accessible Media), Sean Hayes (Microsoft Corporation), David Kirby (British Broadcasting Corporation), Andrew Kirkpatrick (Adobe Systems Inc.), Philippe Le Hégaret (W3C/MIT), Matthew May (Adobe Systems Inc.), Soohong Daniel Park (Samsung Electronics Co., Ltd.), Brad Botkin, Donald Evans, Markus Gylling, Markku Hakkinen, Erik Hodge, Masahiko Kaneko, George Kerscher, Chris Lilley, Thierry Michel, Patrick Schmitz, David Singer.
-
-</p><p>The editor wishes to especially acknowledge the following contributions
-by members: Micheal Dolan (SMPTE time codes, streaming; SMPTE liaison), David
-Kirby (introductory example document; SMPTE time codes, descriptive metadata; EBU/AAF liaison), Geoff Freed (styling
-and example images of style properties), Sean Hayes (advanced profile
-concepts, including applicative timing), Eric Hodge (timing),
-Thierry Michel (metadata), and Dave Singer (animation, scrolling).</p><p>The Timed Text Working Group has benefited in its work from the
-participation and contributions of a number of people not currently
-members of the Working Group, including in particular those named
-below. Affiliations given are those current at the time of their work
-with the WG.</p><p>
-John Birch, Screen Subtitling Systems;
-Bert Bos, W3C (chair, CSS WG);
-Martin Dürst, W3C (leader, I18N Activity);
-Al Gilman (chair, WAI Protocol and Formats WG);
-Philipp Hoschka, W3C (leader, Interaction Domain);
-Chris Lilley, W3C (chair, SVG WG).
-</p><p>The editor wishes to especially acknowledge the following contributions
-by non-members: John Birch (dynamic flow).</p></div></div></body></html>
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