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HTML is good for debugging, but is unsuitable for application use.
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To see the non HTML representation of the XML format, set format=xml.
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<?xml version="1.0"?>
<api>
  <query-continue>
    <allcategories accontinue="Child_Friendly_Crags_around_Montagu" />
  </query-continue>
  <query>
    <allcategories>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Articles which use infobox templates with no data rows</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Bad Kloof</c>
      <c size="9" pages="9" files="0" subcats="0" xml:space="preserve">Bosch Kloof</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Botswana</c>
      <c size="4" pages="4" files="0" subcats="0" xml:space="preserve">Bouldering</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">Cape Town</c>
      <c size="3" pages="3" files="0" subcats="0" xml:space="preserve">Cape Town Bouldering</c>
      <c size="1" pages="0" files="0" subcats="1" xml:space="preserve">Cederberg</c>
      <c size="2" pages="2" files="0" subcats="0" xml:space="preserve">Chess Pieces</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Child Friendly</c>
    </allcategories>
  </query>
</api>