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HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information.
<?xml version="1.0"?>
<api>
  <query-continue>
    <allcategories accontinue="Abuse_and_griefing" />
  </query-continue>
  <query>
    <allcategories>
      <c size="2" pages="1" files="0" subcats="1" xml:space="preserve">2ndAgency</c>
      <c size="2" pages="2" files="0" subcats="0" xml:space="preserve">2ndAgency group members</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">ALL SIDES</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">API</c>
      <c size="36" pages="33" files="0" subcats="3" xml:space="preserve">APIs</c>
      <c size="12" pages="12" files="0" subcats="0" xml:space="preserve">AWG Design Document</c>
      <c size="70" pages="63" files="0" subcats="7" xml:space="preserve">AW Groupies</c>
      <c size="152" pages="150" files="0" subcats="2" xml:space="preserve">AW Groupies Transcripts</c>
      <c size="19" pages="19" files="0" subcats="0" xml:space="preserve">AW Groupies User Pages</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Abuse and Griefing</c>
    </allcategories>
  </query>
</api>