o"></div>),
but will not allow custom tags. Use <a href="../../dart-html/NodeValidatorBuilder/allowCustomElement.html">allowCustomElement</a> to allow
custom tags.<p></p>
    </section>
    
    <section class="summary source-code" id="source">
      <h2><span>Implementation</span></h2>
      <pre class="language-dart"><code class="language-dart">void allowTagExtension(String tagName, String baseName,
    {UriPolicy uriPolicy,
    Iterable&lt;String&gt; attributes,
    Iterable&lt;String&gt; uriAttributes})