Index: source
===================================================================
--- source	(revision 3279)
+++ source	(revision 3280)
@@ -19402,14 +19402,20 @@
   <code>iframe</code> elements, the contents would be parsed as markup
   that could act as fallback content.)</p>
 
-  <p>The content model of <code>iframe</code> elements is text, except
-  that the text must be such that <span class="XXX">... anyone
-  have any bright ideas?</span></p>
-  <!--XXX
-    Gotta handle <script> elements inside <iframe>s that screw around with the DOM on the fly, or that use document.write().
-    Gotta handle <iframe> elements created from script with text contents.
-    Gotta handle the XML case.
-   -->
+  <p>When used in <span>HTML documents</span>, the allowed content
+  model of <code>iframe</code> elements is text, except that invoking
+  the <span>HTML fragment parsing algorithm</span> with the
+  <code>iframe</code> element as the <var title="">context</var>
+  element and the text contents as the <var title="">input</var> must
+  result in a list of nodes that are all <span>phrasing
+  content</span>, with no <span title="parse error">parse
+  errors</span> having occurred, with no <code>script</code> elements
+  being anywhere in the list or as descendants of elements in the
+  list, and with all the elements in the list (including their
+  descendants) being themselves conforming.</p>
+
+  <p>The <code>iframe</code> element must be empty in <span>XML
+  documents</span>.</p>
 
   <p class="note">The <span>HTML parser</span> treats markup inside
   <code>iframe</code> elements as text.</p>