    <a data-link-type="biblio">[CSS21]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="cc123316">pseudo-classes</span>
    </ul>
   <li>
    <a data-link-type="biblio">[HTML]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="8e8f5e6c">ElementInternals</span>
     <li><span class="dfn-paneled" id="b317c3dc">autonomous custom element</span>
     <li><span class="dfn-paneled" id="b6fb7a51">custom element</span>
    </ul>
   <li>
    <a data-link-t