   <?xml version="1.0" encoding="utf-8" ?>
   <C:calendar-query xmlns:D="DAV:"
                    xmlns:C="urn:ietf:params:xml:ns:caldav">
    <D:prop>
      <D:getetag/>
      <C:calendar-data/>
    </D:prop>
    <C:filter>
      <C:comp-filter name="VCALENDAR"/>
    </C:filter>
   </C:calendar-query>