Index: source
===================================================================
--- source	(revision 6816)
+++ source	(working copy)
@@ -95720,12 +95720,13 @@
   body">after body</span>", "<span title="insertion mode: in
   frameset">in frameset</span>", "<span title="insertion mode: after
   frameset">after frameset</span>", "<span title="insertion mode:
-  after after body">after after body</span>", and "<span
+  after after body">after after body</span>", "<span
   title="insertion mode: after after frameset">after after
-  frameset</span>" during the course of the parsing, as described in
-  the <span>tree construction</span> stage. The insertion mode affects
-  how tokens are processed and whether CDATA sections are
-  supported.</p>
+  frameset</span>", and <span title="insertion mode:
+  unknown context">unknown context</span>, during the course of
+  the parsing, as described in the <span>tree construction</span>
+  stage. The insertion mode affects how tokens are processed and
+  whether CDATA sections are supported.</p>
 
   <p>Several of these modes, namely "<span title="insertion mode: in
   head">in head</span>", "<span title="insertion mode: in body">in
@@ -99861,7 +99862,52 @@
 
   </dl>
 
+  <h6 id="parsing-main-unknown-context">The "<dfn title="insertion mode: unknown context">unknown context</dfn>" insertion mode</h6>
 
+  <p>When the user agent is to apply the rules for the "<span title="insertion mode: unknown context">unknown context</span>" <span>insertion mode</span>, the user agent must handle the token as follows:</p>
+
+  <dl class="switch">
+    <dt>A start tag whose tag name is one of: "caption", "colgroup", "tbody", "thead", "tfoot"</dt>
+    <dd>
+      <p>Process the token <span>using the rules for</span> the "<span
+      title="insertion mode: in table">in table</span>" <span>insertion
+      mode</span>.</p>
+
+    <dt>A start tag whose tag name is "tr"</dt>
+    <dd>
+      <p>Process the token <span>using the rules for</span> the "<span
+      title="insertion mode: in table body">in table body</span>"
+      <span>insertion mode</span>.</p>
+
+    <dt>A start tag whose tag name is "col"</dt>
+    <dd>
+      <p>Process the token <span>using the rules for</span> the "<span
+      title="insertion mode: in column group">in column group</span>"
+      <span>insertion mode</span>.</p>
+
+    <dt>A start tag whose tag name is one of: "td", "th"</dt>
+    <dd>
+      <p>Process the token <span>using the rules for</span> the "<span
+      title="insertion mode: in table">in table row</span>"
+      <span>insertion mode</span>.</p>
+
+    <dt>A start tag whose tag name is one of: "rp", "rt</dt>
+    <dd>
+      <p>If the <span>stack of open elements</span> <span title="has
+      an element in scope">has a <code>ruby</code> element in scope</span>,
+      or if the stack of open elements is empty, then <span>generate implied
+      end tags</span>.
+
+      <p><span>Insert an HTML element</span> for the token.
+
+    <dt>Anything else</dt>
+    <dd>
+      <p>Process the token <span>using the rules for</span> the "<span
+      title="insertion mode: in body">in body</span>" <span>insertion
+      mode</span>.</p>
+    </dd>
+  </dl>
+
   <h6 id="parsing-main-inbody">The "<dfn title="insertion mode: in body">in body</dfn>" insertion mode</h6>
 
   <p>When the user agent is to apply the rules for the "<span title="insertion mode: in body">in body</span>" <span>insertion mode</span>, the user agent must handle the token as follows:</p>
@@ -101600,9 +101646,13 @@
   <p>When the steps above require the UA to <dfn>clear the stack
   back to a table context</dfn>, it means that the UA must, while
   the <span>current node</span> is not a <code>table</code>
-  element or an <code>html</code> element, pop elements from the
+  element, an <code>html</code> element, or empty, pop elements from the
   <span>stack of open elements</span>.</p>
 
+  <p class="note">The <span>current node</span> being empty
+  after this process happens in the unknown context insertion
+  mode.</p>
+
   <p class="note">The <span>current node</span> being an
   <code>html</code> element after this process is a <span>fragment
   case</span>.</p>
@@ -116550,4 +116600,4 @@
 <!--END webvtt--><!--END rtc-->
 <!--END html--><!--END dev-html--><!--END w3c-html-->
 <!--END complete--><!--END epub-->
-<!--END validation-->
\ No newline at end of file
+<!--END validation-->