   character.</li>
        <li>The element&#8217;s
        <a href="syntax.html#tag-name" title="syntax-tag-name" id="tag-name_xref3">tag name</a>.</li>
        <li>Optionally, one or more
        <a href="syntax.html#attribute" id="attribute_xref2">attributes</a>,
        each of which
        <a href="terminology.html#must-requirement" id="must-requirement_xref23">must</a>
        be preceded by one or more
        <a href="terminology.html#space" id="space_xref15">space characters</a>.</li>
        <li>O