yntax-attr-single-quoted" id="syntax-attr-single-quoted_xref1">single-quoted attribute-value syntax</a></li>
      <li><a href="syntax.html#syntax-attr-double-quoted" id="syntax-attr-double-quoted_xref1">double-quoted attribute-value syntax</a></li>
    </ol>
<dl>
<dt><dfn id="syntax-attr-empty">empty attribute syntax</dfn></dt>
        <dd>
        <p>Certain attributes may be specified by providing just the
          <a href="syntax.html#attribute-name" id="attribute-name_xref4">attribute name</a>,
      