with things like SOAP envelopes where doctype 
 nodes are not allowed. </dd>
 <dt><code>false</code></dt>
 <dd>[<em>required</em>] (<em>default</em>) Allow doctype nodes in the document. </dd>
 </dl></dd>
 <dt>
 <code>"ignore-unknown-character-denormalizations"</code></dt>
 <dd>
 <dl>
 <dt>
 <code>true</code></dt>
 <dd>[<em>required</em>] (<em>default</em>) If, while verifying full normalization when [<a href='http://www.w3.org/TR/2004/REC-xml11-20040204/'>XML 1.1</a>] is 
 supported, a processor encounters