You are looking at the HTML representation of the XML format.
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>
    <allfileusages afcontinue="BAOS_device_config_DataPoints.png|1137" />
  </query-continue>
  <query>
    <allfileusages>
      <f fromid="1137" ns="6" title="File:BAOS add channel F2 button.png" />
      <f fromid="588" ns="6" title="File:BAOS add command Relay 1.png" />
      <f fromid="1137" ns="6" title="File:BAOS add command Relay 1.png" />
      <f fromid="694" ns="6" title="File:BAOS bind the command relay on off.png" />
      <f fromid="609" ns="6" title="File:BAOS channel and commands properties.png" />
      <f fromid="1137" ns="6" title="File:BAOS connection settings.png" />
      <f fromid="1137" ns="6" title="File:BAOS connection settings ext.png" />
      <f fromid="609" ns="6" title="File:BAOS creation of gateways and channels.png" />
      <f fromid="1137" ns="6" title="File:BAOS creation of gateways and channels.png" />
      <f fromid="609" ns="6" title="File:BAOS device config DataPoints.png" />
    </allfileusages>
  </query>
</api>