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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.
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<?xml version="1.0"?>
<api>
  <query-continue>
    <allfileusages gafcontinue="B1_pi_eff.png|11810" />
  </query-continue>
  <query>
    <pages>
      <page pageid="11619" ns="0" title="TOSCA field plots of the tagger dipole in mapping coordinates" />
      <page pageid="11810" ns="0" title="Start Counter Material Study" />
      <page pageid="18763" ns="0" title="BLTWG Meeting 06/09/2020" />
    </pages>
  </query>
</api>