title: How would one get Google XML Pages to recognize and allow new HTML 5 elements?
body: <p><a href="http://code.google.com/p/gxp/" rel="nofollow">Google XML Pages</a> say they support "standard html as long as it's formatted as xml" but they seem to only support html 4.0. The namespace used for supporting html is <code>http://www.w3.org/1999/xhtml</code> and generating output from a gxp that contains elements like <code>&lt;header&gt;</code> <code>&lt;nav&gt;</code> or <code>&lt;footer&gt;</code> complains that the element is unknown in the <a href="http://www.w3.org/1999/xhtml" rel="nofollow">http://www.w3.org/1999/xhtml</a> namespace.</p>
  
  <p>Is there some different namespace I should be using or do gxps really only support HTML 4?</p>
  
  <p>Here's a reference example gxp file where removing the wrapping <code>header</code> tag works just fine:</p>
  
  <pre><code>&lt;gxp:template
    name='com.example.gxps.Test'
    xmlns:gxp='http://google.com/2001/gxp'
    xmlns='http://www.w3.org/1999/xhtml'&gt;
  &lt;html&gt;
    &lt;body&gt;
      &lt;header&gt;
        &lt;b&gt;
          &lt;gxp:msg&gt;Hello,&lt;/gxp:msg&gt;
          &lt;br/&gt;
          &lt;gxp:msg&gt;World!&lt;/gxp:msg&gt;
        &lt;/b&gt;
      &lt;/header&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  &lt;/gxp:template&gt;
  </code></pre>
  
  <p>As is though, it'll output something like:</p>
  
  <blockquote>
    <blockquote>
      <p>java/com/example/gxps/Test.gxp:7:5:7:5: Unknown element <code>&lt;header&gt;</code> (in <a href="http://www.w3.org/1999/xhtml" rel="nofollow">http://www.w3.org/1999/xhtml</a> namespace)</p>
    </blockquote>
  </blockquote>