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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"?>
    <revisions rvcontinue="8" />
      <page pageid="1" ns="0" title="Main Page">
          <rev user="MediaWiki default" anon="" timestamp="2015-05-04T17:27:06Z" comment="" />
          <rev user="Stage" timestamp="2015-05-04T20:05:48Z" comment="" />
          <rev user="Stage" timestamp="2015-05-04T20:16:19Z" comment="Reverted edits by [[Special:Contributions/Stage|Stage]] ([[User talk:Stage|talk]]) to last revision by [[User:MediaWiki default|MediaWiki default]]" />
          <rev user="Stage" timestamp="2015-05-04T20:16:53Z" comment="Undo revision 3 by [[Special:Contributions/Stage|Stage]] ([[User talk:Stage|talk]])" />
          <rev user="Stage" timestamp="2015-05-04T20:57:06Z" comment="" />