eliot: Edited section 3 per bug 12062, comments 13-14;

eliot: Edited section 3 per bug 12062, comments 13-14;

http://dev.w3.org/cvsweb/html5/html-xhtml-author-guide/html-xhtml-authoring-guide.html?r1=1.68&r2=1.69&f=h

===================================================================
RCS file: /sources/public/html5/html-xhtml-author-guide/html-xhtml-authoring-guide.html,v
retrieving revision 1.68
retrieving revision 1.69
diff -u -d -r1.68 -r1.69
--- html-xhtml-authoring-guide.html 14 Mar 2011 21:03:45 -0000 1.68
+++ html-xhtml-authoring-guide.html 17 Mar 2011 20:09:55 -0000 1.69
@@ -14,7 +14,7 @@
    <a href="http://www.w3.org/"><img height="48" width="72" alt="W3C" src="http://www.w3.org/Icons/w3c_home"/></a>
   </p>
   <h1 class="title" id="title">Polyglot Markup: HTML-Compatible XHTML Documents</h1>
-  <h2 id="w3c-editor-s-draft-05-january-2011">W3C Editor's Draft 4 March 2011</h2>
+  <h2 id="w3c-editor-s-draft-17-march-2011">W3C Editor's Draft 17 March 2011</h2>
   <dl>
    <dt>This version:</dt>
    <dd><a href="http://dev.w3.org/html5/html-xhtml-author-guide/html-xhtml-authoring-guide.html">http://dev.w3.org/html5/html-xhtml-author-guide/html-xhtml-authoring-guide.html</a></dd>
@@ -243,38 +243,32 @@
 <div id="character-encoding" class="section">
 <!--OddPage--><h2><span class="secno">3. </span>Specifying a Document's Character Encoding</h2>
  <p>
-  <a class="internalDFN" href="#dfn-polyglot-markup" title="polyglot markup">Polyglot markup</a> declares character encoding in the following ways, which may be used separately or in combination 
-  (if used in combination, each approach contains identical encoding information):
+  Polyglot markup uses the UTF-8 character encoding, the only character encoding for which both HTML and XML require support. 
+  HTML requires UTF-8 to be explicitly declared to avoid <a href="http://www.w3.org/TR/html5/semantics.html#charset">fallback to a legacy encoding</a> [<cite><a href="#bib-HTML5" rel="biblioentry" class="bibref">HTML5</a></cite>].
+  For XML, UTF-8 is an <a href="http://www.w3.org/TR/2008/REC-xml-20081126/#charencoding">encoding default</a>. 
+  As such, character encoding <em title="may" class="rfc2119">may</em> be left undeclared in XML with the result that UTF-8 is still supported [<cite><a href="#bib-XML10" rel="biblioentry" class="bibref">XML10</a></cite>].
+ </p>
+ <p>
+  <a class="internalDFN" href="#dfn-polyglot-markup" title="polyglot markup">Polyglot markup</a> declares the UTF-8 character encoding in the following ways, which may be used separately or in combination:
   </p><ul>
    <li>Within the document</li>
     <ul>
      <li>By using the Byte Order Mark (BOM) character (preferred).</li>
-     <li>By relying on UTF-8 as the encoding default of XML, used in combination with the HTML <code>&lt;meta charset="UTF-8"/&gt;</code> element.</li>
+     <li>By using <code>&lt;meta charset="UTF-8"/&gt;</code> (the HTML encoding declaration).</li>
     </ul>
-   <li>In the HTTP header of the response [<cite><a href="#bib-HTTP11" rel="biblioentry" class="bibref">HTTP11</a></cite>], as in the following:
-    <p>
-    <code>Content-type: text/html; charset=utf-8</code> 
-    </p>
-    Note that <a class="internalDFN" href="#dfn-polyglot-markup">polyglot markup</a> may use either <code>text/html</code> or <code>application/xhtml+xml</code> for the value of the content type.
+   <li>Outside the document  
+    <ul>
+     <li>By adding <code>"charset=utf-8"</code> to the MIME/HTTP Content-Type header [<cite><a href="#bib-HTTP11" rel="biblioentry" class="bibref">HTTP11</a></cite>], as the following examples show in HTML and XML, respectively: </li>
+    </ul>
+    <pre class="example"><code>Content-type: text/html; charset=utf-8</code></pre>
+    <pre class="example"><code>Content-type: application/xhtml+xml; charset=utf-8</code></pre>
    </li>
   </ul>
  <p></p>
- <p>
-  Using <code>&lt;meta charset="*"/&gt;</code>  has no effect in XML. 
-  Therefore, <a class="internalDFN" href="#dfn-polyglot-markup">polyglot markup</a> may use <code>&lt;meta charset="*"/&gt;</code> provided the document is encoded as UTF-8 and the value of charset is a case-insensitive match for the string "utf-8".
- </p>
- <p>
-  <a class="internalDFN" href="#dfn-polyglot-markup" title="polyglot markup">Polyglot markup</a> uses UTF-8 encoding.
-  The BOM character <em title="may" class="rfc2119">may</em> be used with the UTF-8 encoding (see <a href="http://dev.w3.org/html5/spec/syntax.html#writing">Writing HTML documents</a> in [<cite><a href="#bib-HTML5" rel="biblioentry" class="bibref">HTML5</a></cite>]),
- 
-  and using the BOM character is preferred to not using the BOM 
-character.
-  Because the construct of the BOM character is the same for XML and 
-HTML (unlike the encoding declaration inside the HTTP Content-Type 
-header), 
-  and because the BOM character works in both XML and HTML (unlike the <code>&lt;meta charset="UTF-8"/&gt;</code> declaration of HTML and 
-  the UTF-8 encoding default of XML), 
-  the BOM character can be said to be the most polyglot encoding declaration.
+ <p class="note">
+  The HTML encoding declaration has no effect in XML. 
+  When the HTML encoding declaration is the only encoding declaration, 
+the encoding default from XML makes XML parsers treat content as UTF-8.
  </p>
  <p>
   The <a href="http://www.w3.org/International/questions/qa-html-encoding-declarations">W3C Internationalization (i18n) Group recommends</a>
@@ -1052,6 +1046,8 @@
 </div>
 
 
+
+
 <!-- Appendix -->
 <div id="acknowledgements" class="appendix section">
 <h2><span class="secno">A. </span>Acknowledgements</h2>

Received on Thursday, 17 March 2011 20:11:37 UTC