<sub-class-of type="application/zip"/>
    <!-- Only works if the Content Types or rels file is the first zip entry -->
    <magic priority="50">
      <match value="PK\003\004" type="string" offset="0">
        <match value="[Content_Types].xml" type="string" offset="30"/>
        <match value="_rels/.rels" type="string" offset="30"/>
      </match>
    </magic>
  </mime-type>