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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>
    <allcategories>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">2009</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">Advanced English</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">American Tobacco Company Brands</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">CELIPH</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">Current events</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">Lorillard Tobacco Company Brands</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Pages with broken file links</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">R. J. Reynolds Brands</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">Tobacco brands</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">World Class English Language Training</c>
    </allcategories>
  </query>
</api>