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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="佐野元春的专辑" />
  </query-continue>
  <query>
    <allcategories>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">A型血</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">はっぴいえんど的专辑</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">サンズ・オブ・サン的专辑</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">ムーンライダース的专辑</c>
      <c size="2" pages="0" files="0" subcats="2" xml:space="preserve">专辑</c>
      <c size="4" pages="4" files="0" subcats="0" xml:space="preserve">东京都出身人物</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">井上陽水的专辑</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">人物出生地</c>
      <c size="5" pages="0" files="0" subcats="5" xml:space="preserve">人物出身地</c>
      <c size="1" pages="1" files="0" subcats="0" xml:space="preserve">伊藤銀次的专辑</c>
    </allcategories>
  </query>
</api>