title: Why doesn't form nested in p validate as XHTML
body: <p>Take for instance this XHTML snippet:</p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"&gt;
  &lt;head&gt;
    &lt;title&gt;A webpage&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
    &lt;p&gt;
      &lt;form action="something.php" method="get"&gt;
        &lt;input type="submit" value="Hello"/&gt;
      &lt;/form&gt;
    &lt;/p&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>The tree should be valid, however this won't parse correctly in a browser.</p>