 a
      "<code title="U+0027 APOSTROPHE">'</code>"
      character.</li>
      <li>A
      <a href="syntax.html#permitted-public-ID" id="permitted-public-ID_xref1">permitted public ID</a>
</li>
      <li>A matching <i>quote mark (public ID)</i>, identical to the
      <i>quote mark (public ID)</i> used earlier (either a
      "<code title="U+0022 QUOTATION MARK">"</code>"
      character or a
      "<code title="U+0027 APOSTROPHE">'</code>"
      character).</li>
      <li>Conditionally, depending on wheth