<!-- error: /unexpected node: expecting .*<interpunct>.*parsing: <parens>/ -->
<Octothorpe xmlns:A="uri:type:A" xmlns:B="uri:type:B">
  <colon/>
  <A:section_mark>
    <A:section_mark>
      <interrobang/>
      <A:broken_bar><interpunct>1753</interpunct></A:broken_bar>
    </A:section_mark>
    <interrobang/>
    <A:broken_bar><parens><colon/></parens></A:broken_bar>
  </A:section_mark>
</Octothorpe>