diff --git a/CODEOWNERS b/CODEOWNERS
new file mode 100644
index 00000000..f5233523
--- /dev/null
+++ b/CODEOWNERS
@@ -0,0 +1,3 @@
+# These owners will be the default owners for everything in
+# the repo.
+*       @oreillymedia/tools-team
\ No newline at end of file
diff --git a/htmlbook-xsl/chunk.xsl b/htmlbook-xsl/chunk.xsl
index 95222d9d..fc575802 100755
--- a/htmlbook-xsl/chunk.xsl
+++ b/htmlbook-xsl/chunk.xsl
@@ -320,7 +320,7 @@ sect5:s
       <xsl:number count="*[local-name() = $node-name and @data-type = $node-data-type]" format="01"/>
       <xsl:if test="$original-call = 1">
 	<!-- ToDo: Parameterize me to allow use of different filename extension? -->
-	<xsl:text>.xhtml</xsl:text>
+	<xsl:text>.html</xsl:text>
       </xsl:if>
     </xsl:for-each>
   </xsl:template>
diff --git a/htmlbook-xsl/localizations/en.xml b/htmlbook-xsl/localizations/en.xml
index fffff53d..77ce24c3 100644
--- a/htmlbook-xsl/localizations/en.xml
+++ b/htmlbook-xsl/localizations/en.xml
@@ -511,13 +511,13 @@
 <l:template name="section" text="Section %n"/>
 <l:template name="table" text="Table %n"/>
 </l:context>
-<l:context name="xref-number-and-title"><l:template name="appendix" text="Appendix %n, %t"/>
+<l:context name="xref-number-and-title"><l:template name="appendix" text="Appendix %n, “%t”"/>
 <l:template name="bridgehead" text="Section %n, “%t”"/>
-<l:template name="chapter" text="Chapter %n, %t"/>
+<l:template name="chapter" text="Chapter %n, “%t”"/>
 <l:template name="equation" text="Equation %n, “%t”"/>
 <l:template name="example" text="Example %n, “%t”"/>
 <l:template name="figure" text="Figure %n, “%t”"/>
-<l:template name="part" text="Part %n, %t"/>
+<l:template name="part" text="Part %n, “%t”"/>
 <l:template name="procedure" text="Procedure %n, “%t”"/>
 <l:template name="productionset" text="Production %n, “%t”"/>
 <l:template name="qandadiv" text="Q &amp; A %n, “%t”"/>
diff --git a/htmlbook-xsl/opf.xsl b/htmlbook-xsl/opf.xsl
index 32bbe3d1..6de0062f 100755
--- a/htmlbook-xsl/opf.xsl
+++ b/htmlbook-xsl/opf.xsl
@@ -91,6 +91,100 @@
     </xsl:choose>
   </xsl:template>
 
+<!-- Generic template for handling accessibility properties -->
+<xsl:template name="get.accessibility.property.xml">
+  <xsl:param name="terms.to.process" select="''"/>
+  <xsl:param name="property.type" select="'term'"/> <!-- 'term', 'feature', or 'hazard' -->
+  <xsl:param name="first.call" select="1"/>
+  <xsl:choose>
+    <xsl:when test="$first.call = 1">
+      <xsl:variable name="wrapper.element">
+        <xsl:choose>
+          <xsl:when test="$property.type = 'term'">e:accessibility-terms</xsl:when>
+          <xsl:when test="$property.type = 'feature'">e:accessibility-features</xsl:when>
+          <xsl:when test="$property.type = 'hazard'">e:accessibility-hazards</xsl:when>
+        </xsl:choose>
+      </xsl:variable>
+      <xsl:element name="{$wrapper.element}">
+        <xsl:call-template name="get.accessibility.property.xml">
+          <xsl:with-param name="terms.to.process" select="$terms.to.process"/>
+          <xsl:with-param name="property.type" select="$property.type"/>
+          <xsl:with-param name="first.call" select="0"/>
+        </xsl:call-template>
+      </xsl:element>
+    </xsl:when>
+    <xsl:otherwise>
+      <xsl:choose>
+        <xsl:when test="normalize-space(substring-before($terms.to.process, '&#x0A;')) != ''">
+          <xsl:variable name="term">
+            <xsl:value-of select="normalize-space(substring-before($terms.to.process, '&#x0A;'))"/>
+          </xsl:variable>
+          <xsl:variable name="element.name">
+            <xsl:choose>
+              <xsl:when test="$property.type = 'term'">e:term</xsl:when>
+              <xsl:when test="$property.type = 'feature'">e:feature</xsl:when>
+              <xsl:when test="$property.type = 'hazard'">e:hazard</xsl:when>
+            </xsl:choose>
+          </xsl:variable>
+          <xsl:element name="{$element.name}"><xsl:value-of select="$term"/></xsl:element>
+          <xsl:if test="normalize-space(substring-after($terms.to.process, '&#x0A;')) != ''">
+            <xsl:call-template name="get.accessibility.property.xml">
+              <xsl:with-param name="terms.to.process" select="substring-after($terms.to.process, '&#x0A;')"/>
+              <xsl:with-param name="property.type" select="$property.type"/>
+              <xsl:with-param name="first.call" select="0"/>
+            </xsl:call-template>
+          </xsl:if>
+        </xsl:when>
+        <xsl:when test="normalize-space($terms.to.process) != ''">
+          <xsl:variable name="term">
+            <xsl:value-of select="normalize-space($terms.to.process)"/>
+          </xsl:variable>
+          <xsl:variable name="element.name">
+            <xsl:choose>
+              <xsl:when test="$property.type = 'term'">e:term</xsl:when>
+              <xsl:when test="$property.type = 'feature'">e:feature</xsl:when>
+              <xsl:when test="$property.type = 'hazard'">e:hazard</xsl:when>
+            </xsl:choose>
+          </xsl:variable>
+          <xsl:element name="{$element.name}"><xsl:value-of select="$term"/></xsl:element>
+        </xsl:when>
+      </xsl:choose>
+    </xsl:otherwise>
+  </xsl:choose>
+</xsl:template>
+
+<!-- Parameter for accessibility modes -->
+<xsl:variable name="accessibility.modes.list.xml">
+  <xsl:call-template name="get.accessibility.property.xml">
+    <xsl:with-param name="terms.to.process" select="$access.mode"/>
+    <xsl:with-param name="property.type" select="'term'"/>
+  </xsl:call-template>
+</xsl:variable>
+
+<!-- Parameter for accessibility mode sufficient -->
+<xsl:variable name="accessibility.mode.sufficient.list.xml">
+  <xsl:call-template name="get.accessibility.property.xml">
+    <xsl:with-param name="terms.to.process" select="$access.mode.sufficient"/>
+    <xsl:with-param name="property.type" select="'term'"/>
+  </xsl:call-template>
+</xsl:variable>
+
+<!-- Parameter for accessibility features -->
+<xsl:variable name="accessibility.features.list.xml">
+  <xsl:call-template name="get.accessibility.property.xml">
+    <xsl:with-param name="terms.to.process" select="$accessibility.feature"/>
+    <xsl:with-param name="property.type" select="'feature'"/>
+  </xsl:call-template>
+</xsl:variable>
+
+<!-- Parameter for accessibility hazards -->
+<xsl:variable name="accessibility.hazards.list.xml">
+  <xsl:call-template name="get.accessibility.property.xml">
+    <xsl:with-param name="terms.to.process" select="$accessibility.hazard"/>
+    <xsl:with-param name="property.type" select="'hazard'"/>
+  </xsl:call-template>
+</xsl:variable>
+
   <xsl:template name="generate.mimetype">
     <!-- Outputs "mimetype" file that meets EPUB 3.0 specifications: http://www.idpf.org/epub/30/spec/epub30-ocf.html#physical-container-zip-->
     <!-- Override this template if you want to customize mimetype output -->
@@ -379,6 +473,31 @@
       <xsl:if test="$metadata.ibooks-specified-fonts = 1">
 	<meta property="ibooks:specified-fonts">true</meta>
       </xsl:if>
+
+    <!-- Generate schema:accessMode elements for each term -->
+    <xsl:for-each select="exsl:node-set($accessibility.modes.list.xml)//e:term">
+      <meta property="schema:accessMode"><xsl:value-of select="."/></meta>
+    </xsl:for-each>
+
+    <!-- Generate schema:accessModeSufficient elements for each term -->
+    <xsl:for-each select="exsl:node-set($accessibility.mode.sufficient.list.xml)//e:term">
+        <meta property="schema:accessModeSufficient"><xsl:value-of select="."/></meta>
+    </xsl:for-each>
+
+    <!-- Generate schema:accessibilityFeature elements for each feature -->
+    <xsl:for-each select="exsl:node-set($accessibility.features.list.xml)//e:feature">
+      <meta property="schema:accessibilityFeature"><xsl:value-of select="."/></meta>
+    </xsl:for-each>
+
+    <!-- Generate schema:accessibilityHazard elements for each feature -->
+    <xsl:for-each select="exsl:node-set($accessibility.hazards.list.xml)//e:hazard">
+      <meta property="schema:accessibilityHazard"><xsl:value-of select="."/></meta>
+    </xsl:for-each>
+
+    <!-- Generate schema:accessibilitySummary element if summary is provided -->
+    <xsl:if test="$accessibility.summary != ''">
+      <meta property="schema:accessibilitySummary"><xsl:value-of select="$accessibility.summary"/></meta>
+    </xsl:if>
     </metadata>
   </xsl:template>
 
@@ -421,16 +540,6 @@
       <xsl:if test="$generate.cover.html = 1">
 	<reference href="{$cover.html.filename}" type="cover" title="Cover"/>
       </xsl:if>
-
-      <!-- Generate reference to HTML5 TOC (EPUB Nav Doc) if present (and it should be!)-->
-      <xsl:if test="$html5.toc.node">
-	<xsl:variable name="html5-toc-filename">
-	  <xsl:call-template name="output-filename-for-chunk">
-	    <xsl:with-param name="node" select="$html5.toc.node"/>
-	  </xsl:call-template>
-	</xsl:variable>
-	<reference href="{$html5-toc-filename}" type="toc" title="Table of Contents"/>
-      </xsl:if>
       
       <!-- Calculate <reference element for start-of-text -->
       <!-- Override and customize for different handling, if desired -->
@@ -454,7 +563,7 @@
 	  </xsl:otherwise>
 	</xsl:choose>
       </xsl:variable>
-      <reference href="{$start-of-text-filename}" type="text"/>      
+      <reference href="{$start-of-text-filename}" type="text" title="Start of Text"/>      
     </guide>
   </xsl:template>
 
diff --git a/htmlbook-xsl/param.xsl b/htmlbook-xsl/param.xsl
index 0d2e369b..92694616 100755
--- a/htmlbook-xsl/param.xsl
+++ b/htmlbook-xsl/param.xsl
@@ -223,6 +223,9 @@ sidebar
 refsect1
 refsect2
 refentry
+note
+tip
+warning
 </xsl:param>
 
   <!-- Params for handling of comments in a manuscript -->
diff --git a/htmlbook-xsl/tocgen.xsl b/htmlbook-xsl/tocgen.xsl
index c5ed6bff..39ab3406 100755
--- a/htmlbook-xsl/tocgen.xsl
+++ b/htmlbook-xsl/tocgen.xsl
@@ -23,10 +23,12 @@
   <xsl:template match="h:section[@data-type = 'dedication' or 
 		                 @data-type = 'titlepage' or 
 				 @data-type = 'toc' or 
-				 @data-type = 'colophon' or 
 				 @data-type = 'copyright-page' or 
 				 @data-type = 'halftitlepage']" mode="tocgen"/>
 
+  <!-- Exclude regular colophon but not author bio from TOC generation -->
+	<xsl:template match="h:section[contains(@data-type, 'colophon') and not(contains(@class, 'abouttheauthor'))]" mode="tocgen"/>
+
   <xsl:template match="h:section|h:div[@data-type='part']" mode="tocgen">
     <xsl:param name="toc.section.depth" select="$toc.section.depth"/>
     <xsl:param name="inline.markup.in.toc" select="$inline.markup.in.toc"/>
diff --git a/htmlbook-xsl/xrefgen.xsl b/htmlbook-xsl/xrefgen.xsl
index 23d4ee0e..fb3dba3c 100755
--- a/htmlbook-xsl/xrefgen.xsl
+++ b/htmlbook-xsl/xrefgen.xsl
@@ -245,6 +245,28 @@
       </xsl:otherwise>
     </xsl:choose>
   </xsl:template>
+
+<!-- Special xref-to handling for admonitions (notes, tips, and warnings) -->
+  <xsl:template match="h:div[contains(@data-type, 'note') or contains(@data-type, 'tip') or contains(@data-type, 'warning')]" mode="xref-to">
+    <xsl:choose>
+      <xsl:when test="h:h1[1]">
+  <!-- Choose the first descendant, h1 element, if one exists, drop in text-->
+    <xsl:text>“</xsl:text><xsl:value-of select="h:h1[1]"/><xsl:text>”</xsl:text>
+      </xsl:when>
+      <xsl:otherwise>
+  <!-- Otherwise, throw warning, and print out ??? -->
+  <xsl:call-template name="log-message">
+    <xsl:with-param name="type" select="'WARNING'"/>
+    <xsl:with-param name="message">
+      <xsl:text>Cannot output gentext for XREF to Admonition (id:</xsl:text>
+      <xsl:value-of select="@id"/>
+      <xsl:text>) that does not contain a descendant h1 element</xsl:text>
+    </xsl:with-param>
+  </xsl:call-template>
+  <xsl:text>???</xsl:text>
+      </xsl:otherwise>
+    </xsl:choose>
+  </xsl:template>
   
   <!-- ADDING HANDLING FOR XREFS TO EQUATION -->
   <!-- Adapted from docbook-xsl templates in xhtml/xref.xsl -->
@@ -586,23 +608,6 @@
 
 </xsl:template>
 
-  <xsl:template match="h:section[contains(@data-type, 'chapter') or contains(@data-type, 'appendix')] | h:div[contains(@data-type, 'part')]" mode="insert.title.markup">
-  <xsl:param name="purpose"/>
-  <xsl:param name="xrefstyle"/>
-  <xsl:param name="title"/>
-
-  <xsl:choose>
-    <xsl:when test="$purpose = 'xref'">
-      <em xmlns:xslo="http://www.w3.org/1999/XSL/Transform">
-        <xsl:copy-of select="$title"/>
-      </em>
-    </xsl:when>
-    <xsl:otherwise>
-      <xsl:copy-of select="$title"/>
-    </xsl:otherwise>
-  </xsl:choose>
-</xsl:template>
-
 <!-- ============================================================ -->
 
 <!-- Adapted from docbook-xsl common/l10.xsl stylesheet -->
diff --git a/htmlbook-xsl/xspec/fileextension.xspec b/htmlbook-xsl/xspec/fileextension.xspec
old mode 100755
new mode 100644
diff --git a/htmlbook-xsl/xspec/opf.xspec b/htmlbook-xsl/xspec/opf.xspec
index e29b3fa4..14cee535 100755
--- a/htmlbook-xsl/xspec/opf.xspec
+++ b/htmlbook-xsl/xspec/opf.xspec
@@ -544,7 +544,9 @@ and the script from https://github.com/xspec/xspec.">
       <!-- Note, we can't access document context from a named template, so we can't check hrefs here, but at least we can check for existence of elements -->
       <!-- ToDo: parameterize context node for generate-guide so hrefs can be tested, and pending tests can be filled in -->
       <x:expect label="There should be a reference element for the cover if generate.cover.html is enabled" test="exists(/opf:guide/opf:reference[@type='cover'])"/>
-      <x:expect label="There should be a reference element to the EPUB Nav doc" test="exists(/opf:guide/opf:reference[@type='toc'])"/>
+      <!-- Note, we are no longer including the TOC element because of an error when sending EPUB to Amazon -->
+      <x:expect label="There *should not* be a reference element to the EPUB Nav doc" test="not(exists(/opf:guide/opf:reference[@type='toc']))"/>
+      <x:expect label="There should be a title element in the start of text reference" test="exists(/opf:guide/opf:reference[contains(@type='text' and @title='Start of Text')])"/>
       <x:scenario label="With generate.cover.html disabled">
 	<x:call>
 	  <x:param name="generate.cover.html"/>
diff --git a/htmlbook-xsl/xspec/tocgen.xspec b/htmlbook-xsl/xspec/tocgen.xspec
index 92c797f6..2662ba5b 100755
--- a/htmlbook-xsl/xspec/tocgen.xspec
+++ b/htmlbook-xsl/xspec/tocgen.xspec
@@ -235,8 +235,34 @@ and the script from https://github.com/xspec/xspec.">
     </x:context>
     <x:expect label="An entry 'li' *should not* be generated" select="()"/>
   </x:scenario>
+
+    <x:scenario label="When an abouttheauthor colophon is matched in tocgen mode">
+    <x:context select="(//h:section[@data-type='colophon'])[1]" mode="tocgen">>
+      <x:param name="toc.section.depth" select="3"/>
+      <body data-type="book">
+        <section data-type="chapter">
+          <h1>First chapter</h1>
+          <section data-type="sect1">
+            <h1>First sect1</h1>
+            <p>A paragraph</p>
+          </section>
+        </section>
+        <section data-type="chapter">
+          <h1>Second chapter</h1>
+          <p>A paragraph</p>
+        </section>
+        <section data-type="colophon" class="abouttheauthor">
+          <h1>About the Author</h1>
+          <p>There should be an entry for this in the TOC</p>
+        </section>
+      </body>
+    </x:context>
+    <x:expect label="An entry 'li' should be generated">
+      <li data-type="colophon"><a href="...">...</a></li>
+    </x:expect>
+  </x:scenario>
   
-  <x:scenario label="When a frontmatter or backmatter section is matched in tocgen mode">
+  <x:scenario label="When a standard colophon is matched in tocgen mode">
     <x:context select="(//h:section[@data-type='colophon'])[1]" mode="tocgen">>
       <x:param name="toc.section.depth" select="3"/>
       <body data-type="book">
@@ -252,7 +278,7 @@ and the script from https://github.com/xspec/xspec.">
           <p>A paragraph</p>
         </section>
         <section data-type="colophon">
-          <h1>About the Author</h1>
+          <h1>Colophon</h1>
           <p>There shouldn't be an entry for this in the TOC</p>
         </section>
       </body>
diff --git a/htmlbook-xsl/xspec/xrefgen.xspec b/htmlbook-xsl/xspec/xrefgen.xspec
index 432f12b2..739e6107 100755
--- a/htmlbook-xsl/xspec/xrefgen.xspec
+++ b/htmlbook-xsl/xspec/xrefgen.xspec
@@ -1419,21 +1419,21 @@ and the script from https://github.com/xspec/xspec.">
 We were using the Saxon JAR file version SAXON HE 9.5.1.2
 and the script from https://github.com/xspec/xspec.">
       <x:context select="//h:a[@id='chap-num-title-xref']"/>
-      <x:expect label="it should return chapter label, number, and title"><a href="#awesome_chap" id="chap-num-title-xref" data-type="xref" data-xrefstyle="chap-num-title" data-xref-pagenum-style="...">Chapter&#xa0;1, <em>AWESOME CHAPTER</em></a></x:expect>
+      <x:expect label="it should return chapter label, number, and title"><a href="#awesome_chap" id="chap-num-title-xref" data-type="xref" data-xrefstyle="chap-num-title" data-xref-pagenum-style="...">Chapter&#xa0;1, “AWESOME CHAPTER“</a></x:expect>
     </x:scenario>
 
     <x:scenario label="of 'app-num-title'" pending="We received an  error when trying to run this scenario.
 We were using the Saxon JAR file version SAXON HE 9.5.1.2
 and the script from https://github.com/xspec/xspec.">
       <x:context select="//h:a[@id='app-num-title-xref']"/>
-      <x:expect label="it should return appendix label, number, and title"><a href="#awesome_app" id="app-num-title-xref" data-type="xref" data-xrefstyle="app-num-title" data-xref-pagenum-style="...">Appendix&#xa0;A, <em>Appendix Title</em></a></x:expect>
+      <x:expect label="it should return appendix label, number, and title"><a href="#awesome_app" id="app-num-title-xref" data-type="xref" data-xrefstyle="app-num-title" data-xref-pagenum-style="...">Appendix&#xa0;A, “Appendix Title“</a></x:expect>
     </x:scenario>
 
     <x:scenario label="of 'part-num-title'" pending="We received an  error when trying to run this scenario.
 We were using the Saxon JAR file version SAXON HE 9.5.1.2
 and the script from https://github.com/xspec/xspec.">
       <x:context select="//h:a[@id='part-num-title-xref']"/>
-      <x:expect label="it should return part label, number, and title"><a href="#awesome_part" id="part-num-title-xref" data-type="xref" data-xrefstyle="part-num-title" data-xref-pagenum-style="...">Part&#xa0;I, <em>I'm Part of the Solution!</em></a></x:expect>
+      <x:expect label="it should return part label, number, and title"><a href="#awesome_part" id="part-num-title-xref" data-type="xref" data-xrefstyle="part-num-title" data-xref-pagenum-style="...">Part&#xa0;I, “I'm Part of the Solution!“</a></x:expect>
     </x:scenario>
 
     <x:scenario label="of 'select:nopage'" pending="We received an  error when trying to run this scenario.
@@ -1657,5 +1657,114 @@ and the script from https://github.com/xspec/xspec.">
     </x:call>
     <x:expect label="Trimmed URL should be returned as is">oreilly.com</x:expect>
   </x:scenario>
-  
+
+<!-- XREFS for Admonitions begins -->
+  <x:scenario label="When an XREF points to an admonition with a title">
+    <x:context>
+        <section data-type="chapter">
+        <div data-type="note" id="note_admonition">
+          <h1>I am a note title!</h1>
+          <p>This is a note</p>
+        </div>
+          <div data-type="tip" id="tip_admonition">
+          <h1>I am a tip title!</h1>
+          <p>This is a tip</p>
+        </div>
+        <div data-type="warning" id="warning_admonition">
+          <h1>I am a warning title!</h1>
+          <p>This is a warning</p>
+        </div>
+  </section>
+</x:context>
+
+  <x:scenario label="When an XREF points to a note with a title">
+  <x:context mode="xref-to" select="(//h:div[@data-type='note'])[1]"/>
+    <x:expect label="Gentext should be created for the xref">“I am a note title!”</x:expect>
+  </x:scenario>
+    <x:scenario label="When an XREF points to a tip with a title">
+  <x:context mode="xref-to" select="(//h:div[@data-type='tip'])[1]"/>
+    <x:expect label="Gentext should be created for the xref">“I am a tip title!”</x:expect>
+  </x:scenario>
+
+  <x:scenario label="When an XREF points to a warning with a title">
+  <x:context mode="xref-to" select="(//h:div[@data-type='warning'])[1]"/>
+    <x:expect label="Gentext should not be created for the xref">“I am a warning title!”</x:expect>
+  </x:scenario>
+ </x:scenario>
+
+<x:scenario label="When an XREF points to an admonition without a title">
+  <x:context>
+    <section data-type="chapter">
+        <div data-type="note" id="note_admonition">
+          <p>This is a note</p>
+        </div>
+        <div data-type="tip" id="tip_admonition">
+          <p>This is a tip</p>
+        </div>
+        <div data-type="warning" id="warning_admonition">
+          <p>This is a warning</p>
+        </div>
+  </section>
+  </x:context>
+
+    <x:scenario label="When an XREF points to a note without a title">
+  <x:context mode="xref-to" select="(//h:div[@data-type='note'])[1]"/>
+    <x:expect label="Gentext should not be created for the xref">???</x:expect>
+  </x:scenario>
+
+  <x:scenario label="When an XREF points to a tip without a title">
+  <x:context mode="xref-to" select="(//h:div[@data-type='tip'])[1]"/>
+    <x:expect label="Gentext should be created for the xref">???</x:expect>
+  </x:scenario>
+
+  <x:scenario label="When an XREF points to a warning without a title">
+  <x:context mode="xref-to" select="(//h:div[@data-type='warning'])[1]"/>
+    <x:expect label="Gentext should not be created for the xref">???</x:expect>
+  </x:scenario>
+</x:scenario>
+
+  <x:scenario label="When an XREF points to any admonition">
+  <x:context>
+  <x:param name="xref.elements.pagenum.in.class">
+    note
+    tip
+    warning
+  </x:param>
+  <section data-type="chapter">
+    <p>XREF to Note: <a data-type="xref" href="#note1"/></p>
+
+    <p>XREF to Tip: <a data-type="xref" href="#tip1"/></p>
+
+    <p>XREF to Warning: <a data-type="xref" href="#warning1"/></p>
+
+        <div data-type="note" id="note1">
+          <h1>I am a title!</h1>
+          <p>This is a note</p>
+        </div>
+
+        <div data-type="tip" id="tip1">
+          <h1>I am a title!</h1>
+          <p>This is a tip</p>
+        </div>
+
+        <div data-type="warning" id="warning1">
+          <h1>I am a title!</h1>
+          <p>This is a warning</p>
+        </div>
+  </section>
+  </x:context>
+   <x:scenario label="When an XREF points to any Note">
+    <x:context select="(//h:a[@data-type='xref'])[1]"/>
+    <x:expect label="The xref should generate with a pagenum class"><a href="..." data-type="xref" data-xref-pagenum-style="..." class="pagenum">...</a></x:expect>
+   </x:scenario>
+   <x:scenario label="When an XREF points to any Tip">
+    <x:context select="(//h:a[@data-type='xref'])[2]"/>
+    <x:expect label="The xref should generate with a pagenum class"><a href="..." data-type="xref" data-xref-pagenum-style="..." class="pagenum">...</a></x:expect>
+   </x:scenario>
+   <x:scenario label="When an XREF points to any Warning">
+    <x:context select="(//h:a[@data-type='xref'])[3]"/>
+    <x:expect label="The xref should generate with a pagenum class"><a href="..." data-type="xref" data-xref-pagenum-style="..." class="pagenum">...</a></x:expect>
+   </x:scenario>
+  </x:scenario>
+  <!-- TOOLSREQ-6431 ends -->
 </x:description>
diff --git a/index.html b/index.html
index 1969872a..78a3ade7 100644
--- a/index.html
+++ b/index.html
@@ -3,43 +3,43 @@
   <head>
     <title>HTMLBook</title>
     <meta charset="utf-8">
-    <script src="//www.w3.org/Tools/respec/respec-w3c-common" async class="remove"></script>
+    <script src="https://www.w3.org/Tools/respec/respec-w3c" async class="remove"></script>
     <script class="remove">
       var respecConfig = {
           additionalCopyrightHolders: "Copyright &copy; 2014 O&#x2019;Reilly Media, Inc.",
           specStatus: "unofficial",
           shortName:  "htmlbook",
           editors: [
-                {   name:       "Sanders Kleinfeld",
-                    url:        "http://oreilly.com",
+                {   name:       "O'Reilly Tools Team",
+                    url:        "https://oreilly.com",
                     company:    "O&#x2019;Reilly Media, Inc",
-                    companyURL: "http://oreilly.com" }
+                    companyURL: "https://oreilly.com" }
           ],
           localBiblio: {
              "DITA": {
                 title: "Darwin Information Typing Architecture (DITA) Version 1.2",
-                href: "http://docs.oasis-open.org/dita/v1.2/spec/DITA1.2-spec.html",
+                href: "https://docs.oasis-open.org/dita/v1.2/spec/DITA1.2-spec.html",
                 authors: ["Kristen James Eberlein", "Robert D. Anderson", "Gershon Joseph"]
              },
              "DOCBOOK": { 
                 title: "The DocBook Document Type",
-                href: "http://www.docbook.org/specs/docbook-4.5-spec.html",
+                href: "https://www.docbook.org/specs/docbook-4.5-spec.html",
                 authors: ["Norman Walsh"],
                 publisher: "OASIS",
              },
              "EPUB3": {
                 title: "EPUB 3 Overview",
-                href: "http://www.idpf.org/epub/30/spec/",
+                href: "https://www.idpf.org/epub/30/spec/",
                 publisher: "IDPF"
              },
              "EPUB3SSV" : {
                 title: "EPUB 3 Structural Semantics Vocabulary",
-                href: "http://www.idpf.org/epub/vocab/structure/",
+                href: "https://www.idpf.org/epub/vocab/structure/",
                 publisher: "IDPF",
              },
              "EPUBINDEX": {
                 title: "EPUB Indexes 1.0",
-                href: "http://www.idpf.org/epub/idx/",
+                href: "https://www.idpf.org/epub/idx/",
                 publisher: "IDPF"
              }
           } 
@@ -79,19 +79,21 @@
     </section>
     <section>
       <h2>Notes on the HTMLBook Specification</h2>
-      <p>Requirements for HTML5 elements in the HTMLBook specification are below. Special semantic inflections for <code>data-type</code> attributes, unless otherwise noted, come from <a href="http://idpf.org/epub/vocab/structure/">EPUB 3 Structural Semantics Vocabulary</a></p>
+      <p>Requirements for HTML5 elements in the HTMLBook specification are below. Special semantic inflections for <code>data-type</code> attributes, unless otherwise noted, come from <a href="https://idpf.org/epub/vocab/structure/">EPUB 3 Structural Semantics Vocabulary</a></p>
       <p>Many content models refer to &ldquo;Block Elements&rdquo; or &ldquo;Inline Elements&rdquo;; please see <a href="#block_elements">Block Elements</a> and <a href="#inline_elements">Inline Elements</a> for the corresponding list of HTML5 elements that belong to each of these categories.</p>
-      <p>If no content model or attribute requirements are explicitly specified, then HTMLBook adopts the corresponding requirements in the [[!HTML5]] Specification</p>
+      <p>If no content model or attribute requirements are explicitly specified, then HTMLBook adopts the corresponding requirements in the [[HTML5]] Specification</p>
     </section>
     <section>
       <h2>Revision History and Notes</h2>
       <dl>
+  <dt>7 February 2023</dt>
+  <dd>Changed Sidebar section to reflect new standard of using &lt;h1&gt; over &lt;h5&gt; as the heading element. Also addressed ReSpec deprecation warnings by updating some attributes and replacing http: URLs with https:</dd>
 	<dt>16 September 2015</dt>
 	<dd>Added informative section on reference entries</dd>
 	<dt>25 February 2015</dt>
 	<dd>Clarified HTMLBook specifications for inline semantics/tagging</dd>
 	<dt>8 April 2014</dt>
-	<dd>Updated specifications for section subtitles to comply with best practices set forth in <a href="http://www.w3.org/TR/html5/common-idioms.html#common-idioms">&ldquo;Common idioms without dedicated elements&rdquo;</a> in [[!HTML5]] Specification.</dd>
+	<dd>Updated specifications for section subtitles to comply with best practices set forth in <a href="https://www.w3.org/TR/html5/common-idioms.html#common-idioms">&ldquo;Common idioms without dedicated elements&rdquo;</a> in [[!HTML5]] Specification.</dd>
         <dt>29 December 2013</dt>
         <dd>Minor revisions for clarity</dd>
         <dt>13 August 2013</dt>
@@ -256,7 +258,7 @@ <h2>Part</h2>
         <h2>Table of Contents</h2>
         <p><strong>HTML element</strong>: <code>&lt;nav&gt;</code></p>
         <p><strong>Attribute requirements</strong>: <code>data-type="toc"</code></p>
-        <p><strong>Content Model</strong>: The TOC must be conformant to the specs for the [[EPUB3]] <a href="http://www.idpf.org/epub/30/spec/epub30-contentdocs-20111011.html#sec-xhtml-nav">Navigation document</a>. First child is zero or more <a href="#_headings">Heading elements</a> (<code>&lt;h1&gt;-&lt;h6&gt;</code>), followed by an <code>&lt;ol&gt;</code> (with <code>&lt;li&gt;</code> children that can contain only a <code>&lt;span&gt;</code> element or an <code>&lt;a&gt;</code> element plus an optional <code>&lt;ol&gt;</code> child)</p>
+        <p><strong>Content Model</strong>: The TOC must be conformant to the specs for the [[EPUB3]] <a href="https://www.idpf.org/epub/30/spec/epub30-contentdocs-20111011.html#sec-xhtml-nav">Navigation document</a>. First child is zero or more <a href="#_headings">Heading elements</a> (<code>&lt;h1&gt;-&lt;h6&gt;</code>), followed by an <code>&lt;ol&gt;</code> (with <code>&lt;li&gt;</code> children that can contain only a <code>&lt;span&gt;</code> element or an <code>&lt;a&gt;</code> element plus an optional <code>&lt;ol&gt;</code> child)</p>
         <p>
           <strong>Example</strong>
         </p>
@@ -336,10 +338,10 @@ <h2>Paragraph</h2>
         <h2>Sidebar</h2>
         <p><strong>HTML element</strong>: <code>&lt;aside&gt;</code></p>
         <p><strong>Attribute requirements</strong>: <code>data-type="sidebar"</code></p>
-        <p><strong>Content model</strong>: Zero or one <code>&lt;h5&gt;</code> element that contains the sidebar title); then zero or more <a href="#block_elements">Block Elements</a></p>
+        <p><strong>Content model</strong>: Zero or one <code>&lt;h1&gt;</code> element that contains the sidebar title); then zero or more <a href="#block_elements">Block Elements</a></p>
         <p><strong>Example</strong>:</p>
         <pre data-type="programlisting">&lt;aside data-type="sidebar"&gt;
-  &lt;h5&gt;Amusing Digression&lt;/h5&gt;
+  &lt;h1&gt;Amusing Digression&lt;/h1&gt;
   &lt;p&gt;Did you know that in Boston, they call it "soda", and in Chicago, they call it "pop"?&lt;/p&gt;
 &lt;/aside&gt;</pre>
       </section>
@@ -562,7 +564,7 @@ <h2>Equation</h2>
         <p><strong>Example</strong>:</p>
         <pre data-type="programlisting">&lt;div data-type="equation"&gt;
 &lt;h5&gt;Pythagorean Theorem&lt;/h5&gt;
-&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;
+&lt;math xmlns="https://www.w3.org/1998/Math/MathML"&gt;
   &lt;msup&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msup&gt;
   &lt;mo&gt;+&lt;/mo&gt;
   &lt;msup&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msup&gt;
@@ -575,7 +577,7 @@ <h2>Equation</h2>
         <h2>Reference Entries (refentries)</h2>
         <p><strong>Suggested HTML element</strong>: <code>&lt;div&gt;</code></p>
         <p><strong>Suggested semantics</strong>: <code>class="refentry"</code></p>
-        <p><strong>Note:</strong> HTMLBook does not currently normatively specify structural semantics for reference entries as they are conceived in <a href="http://www.docbook.org/tdg/en/html/refentry.html">DocBook</a> ([[DOCBOOK]]) or <a href="http://docs.oasis-open.org/dita/v1.2/os/spec/common/reference2.html#reference2">DITA</a> ([[DITA]]). Use of <code>&lt;div class="refentry"&gt;</code> is suggested for marking up reference entries. The following example illustrates XHTML5 markup one might use for refentry content, which captures DocBook-style semantics</p>
+        <p><strong>Note:</strong> HTMLBook does not currently normatively specify structural semantics for reference entries as they are conceived in <a href="https://www.docbook.org/tdg/en/html/refentry.html">DocBook</a> ([[DOCBOOK]]) or <a href="https://docs.oasis-open.org/dita/v1.2/os/spec/common/reference2.html#reference2">DITA</a> ([[DITA]]). Use of <code>&lt;div class="refentry"&gt;</code> is suggested for marking up reference entries. The following example illustrates XHTML5 markup one might use for refentry content, which captures DocBook-style semantics</p>
         <p><strong>Example refentry paralleling [[DOCBOOK]]</strong>:</p>
         <pre data-type="programlisting">&lt;div class="refentry">
   &lt;header&gt;
@@ -594,7 +596,7 @@ <h2>Reference Entries (refentries)</h2>
     </section>
     <section data-type="sect1" id="_inline_elements">
       <h1>Inline Elements</h1>
-	<div class="note">HTMLBook is primarily focused on codifying <em>structural semantics</em> for book authoring, and as such, it does not formally define specifications for phrase-level semantics (such as the DocBook <a href="http://www.docbook.org/tdg/en/html/varname.html"><code>varname</code></a> or <a href="http://www.docbook.org/tdg/en/html/personname.html"><code>personname</code></a> elements) beyond that which is codified in the [[!HTML5]] specification. Nor does it formally define specifications for purely presentational markup (such as underline or strikethrough rendering). HTMLBook users are encouraged to employ the appropriate standard HTML5 phrasing elements for inline semantics when available (e.g., <code>&lt;strong&gt;</code>, <code>&lt;em&gt;</code>, <code>&lt;s&gt;</code>, <code>&lt;u&gt;</code>) and to use <code>&lt;span&gt;</code> elements with custom-defined classes in other cases, as illustrated in the following examples.</div>
+	<div class="note">HTMLBook is primarily focused on codifying <em>structural semantics</em> for book authoring, and as such, it does not formally define specifications for phrase-level semantics (such as the DocBook <a href="https://www.docbook.org/tdg/en/html/varname.html"><code>varname</code></a> or <a href="https://www.docbook.org/tdg/en/html/personname.html"><code>personname</code></a> elements) beyond that which is codified in the [[!HTML5]] specification. Nor does it formally define specifications for purely presentational markup (such as underline or strikethrough rendering). HTMLBook users are encouraged to employ the appropriate standard HTML5 phrasing elements for inline semantics when available (e.g., <code>&lt;strong&gt;</code>, <code>&lt;em&gt;</code>, <code>&lt;s&gt;</code>, <code>&lt;u&gt;</code>) and to use <code>&lt;span&gt;</code> elements with custom-defined classes in other cases, as illustrated in the following examples.</div>
       <section data-type="sect2" id="_emphasis_generally_for_italic">
         <h2>Emphasis (generally for italic)</h2>
         <p><strong>HTML element</strong>: <code>&lt;em&gt;</code></p>
@@ -697,7 +699,7 @@ <h2>Headings</h2>
 sect3 title -&gt; h3
 sect4 title -&gt; h4
 sect5 title -&gt; h5
-sidebar title -&gt; h5</pre>
+sidebar title -&gt; h1</pre>
       </section>
       <section data-type="sect2" id="header_block">
 	<h2>Header</h2>
@@ -725,7 +727,7 @@ <h2>Video</h2>
 &lt;source src="video/html5_asteroids.mp4" type="video/mp4"/&gt;
 &lt;source src="video/html5_asteroids.ogg" type="video/ogg"/&gt;
 &lt;em&gt;Sorry, the &amp;lt;video&amp;gt; element not supported in your
-  reading system. View the video online at http://example.com.&lt;/em&gt;
+  reading system. View the video online at https://example.com.&lt;/em&gt;
 &lt;/video&gt;</pre>
       </section>
       <section data-type="sect2" id="_audio">
@@ -738,7 +740,7 @@ <h2>Audio</h2>
 &lt;source src="audio/new_slang.mp3" type="audio/mp3"/&gt;
 &lt;source src="audionew_slang.ogg" type="audio/ogg"/&gt;
 &lt;em&gt;Sorry, the &amp;lt;audio&amp;gt; element is not supported in your
-  reading system. Hear the audio online at http://example.com.&lt;/em&gt;
+  reading system. Hear the audio online at https://example.com.&lt;/em&gt;
 &lt;/audio&gt;</pre>
       </section>
       <section data-type="sect2" id="_canvas">
@@ -749,7 +751,7 @@ <h2>Canvas</h2>
 Canvas handling.</p>
         <p><strong>Examples</strong>:</p>
         <pre data-type="programlisting">&lt;canvas id="canvas" width="400" height="400"&gt;
- Your browser does not support the HTML 5 Canvas. See the interactive example at http://example.com.
+ Your browser does not support the HTML 5 Canvas. See the interactive example at https://example.com.
 &lt;/canvas&gt;</pre>
       </section>
     </section>
@@ -782,7 +784,7 @@ <h2>Metadata points</h2>
       <h1>Element Classification</h1>
       <section data-type="sect2" id="block_elements">
         <h2>Block Elements</h2>
-        <p>In HTMLBook, the majority of elements classified by the HTML5 specification as <a href="http://www.w3.org/TR/html5/dom.html#flow-content">Flow Content</a> (minus elements also categorized as <a href="http://www.w3.org/TR/html5/dom.html#heading-content">Heading Content</a>, <a href="http://www.w3.org/TR/html5/dom.html#phrasing-content">Phrasing Content</a>, and <a href="http://www.w3.org/TR/html5/dom.html#sectioning-content">Sectioning Content</a>) are considered to be Block Elements. Here is a complete list:</p>
+        <p>In HTMLBook, the majority of elements classified by the HTML5 specification as <a href="https://www.w3.org/TR/html5/dom.html#flow-content">Flow Content</a> (minus elements also categorized as <a href="https://www.w3.org/TR/html5/dom.html#heading-content">Heading Content</a>, <a href="https://www.w3.org/TR/html5/dom.html#phrasing-content">Phrasing Content</a>, and <a href="https://www.w3.org/TR/html5/dom.html#sectioning-content">Sectioning Content</a>) are considered to be Block Elements. Here is a complete list:</p>
         <ul>
           <li>
             <p>
@@ -865,7 +867,7 @@ <h2>Block Elements</h2>
             </p>
           </li>
           <li>
-            <p><code>&lt;math&gt;</code> (In MathML vocabulary; must be namespaced under <a href="http://www.w3.org/1998/Math/MathML">http://www.w3.org/1998/Math/MathML</a>)</p>
+            <p><code>&lt;math&gt;</code> (In MathML vocabulary; must be namespaced under <a href="https://www.w3.org/1998/Math/MathML">https://www.w3.org/1998/Math/MathML</a>)</p>
           </li>
           <li>
             <p>
@@ -893,7 +895,7 @@ <h2>Block Elements</h2>
             </p>
           </li>
           <li>
-            <p><code>&lt;svg&gt;</code> (In SVG vocabulary; must be namespaced under <a href="http://www.w3.org/2000/svg">http://www.w3.org/2000/svg</a>)</p>
+            <p><code>&lt;svg&gt;</code> (In SVG vocabulary; must be namespaced under <a href="https://www.w3.org/2000/svg">https://www.w3.org/2000/svg</a>)</p>
           </li>
           <li>
             <p>
@@ -914,7 +916,7 @@ <h2>Block Elements</h2>
       </section>
       <section data-type="sect2" id="inline_elements">
         <h2>Inline Elements</h2>
-        <p>In HTMLBook, the majority of elements classified by the HTML5 specification as <a href="http://www.w3.org/TR/html5/dom.html#phrasing-content">Phrasing Content</a> are considered to be Inline Elements. Here is a complete list:</p>
+        <p>In HTMLBook, the majority of elements classified by the HTML5 specification as <a href="https://www.w3.org/TR/html5/dom.html#phrasing-content">Phrasing Content</a> are considered to be Inline Elements. Here is a complete list:</p>
         <ul>
           <li>
             <p>
diff --git a/schema/htmlbook.xsd b/schema/htmlbook.xsd
index d2961a23..d114f658 100644
--- a/schema/htmlbook.xsd
+++ b/schema/htmlbook.xsd
@@ -1761,7 +1761,7 @@
 <!-- Sidebar; primarily for <aside> -->
 <xs:complexType name="sidebar">
   <xs:sequence>
-    <xs:element ref="h5" minOccurs="0"/> <!-- Unlike other sections, sidebar titles are optional -->
+    <xs:element ref="h1" minOccurs="0"/> <!-- Unlike other sections, sidebar titles are optional -->
     <xs:group ref="figure_elements" minOccurs="0" maxOccurs="unbounded"/>
   </xs:sequence>
   <!-- ToDo: require data-type attr restriction of "sidebar" here? -->
diff --git a/schema/svg/SVG.xsd b/schema/svg/SVG.xsd
index 4cd0a3be..a298f7f4 100644
--- a/schema/svg/SVG.xsd
+++ b/schema/svg/SVG.xsd
@@ -1102,6 +1102,7 @@
     <attribute name="style" type="svg:StyleSheetType" use="optional"/>
     <attributeGroup ref="svg:PresentationAttributes-All"/>
     <attribute name="viewBox" type="svg:ViewBoxSpecType" use="optional"/>
+    <attribute name="version" type="double" use="optional"/>
     <attribute name="preserveAspectRatio" type="svg:PreserveAspectRatioSpecType" default="xMidYMid meet"/>
     <attribute name="zoomAndPan" default="magnify">
       <simpleType>