"syntax-text_xref4">text</a>,
          optionally including
          "<code title="U+003C LESS-THAN SIGN">&lt;</code>"
          characters
          
          
          </li>
          <li><a href="syntax.html#syntax-ambiguous-ampersand" id="syntax-ambiguous-ampersand_xref2">ambiguous ampersands</a></li>
        </ul>
<p>Non-replaceable character data has the following restrictions:</p>
        <ul>
<li>
<a href="terminology.html#must-requirement" id="must-requirement_xref46">must</a>
          not con