HTTP/1.1 403 Forbidden
Date: Dow, 01 Jan 2000 00:00:00 GMT
DAV: 1, 2, access-control, calendar-access, calendar-schedule, extended-mkcol, calendar-proxy, bind, calendar-auto-schedule
Content-Length: 223
Content-Type: text/xml; charset="utf-8"

<?xml version="1.0" encoding="utf-8" ?>
<error xmlns="DAV:">
 <need-privileges>
  <resource>
   <href>/caldav.php/bogusprincipal/</href>
   <privilege>
    <read/>
   </privilege>
  </resource>
 </need-privileges>
</error>