diff --git a/inc/caldav-DELTICKET.php b/inc/caldav-DELTICKET.php
new file mode 100644
index 00000000..4ac3fb02
--- /dev/null
+++ b/inc/caldav-DELTICKET.php
@@ -0,0 +1,45 @@
+<?php
+/**
+* CalDAV Server - handle DELTICKET method in line with defunct proposed RFC
+*   from:  http://tools.ietf.org/html/draft-ito-dav-ticket-00
+*
+* Why are we using a defunct RFC?  Well, we want to support some kind of system
+* for providing a URI to people to give out for granting privileged access
+* without requiring logins.  Using a defunct proposed spec seems better than
+* inventing our own.  As well as Xythos, Cosmo follows this specification,
+* with some documented variations, which we will also follow.  In particular
+* we use the xmlns="http://www.xythos.com/namespaces/StorageServer" rather
+* than the DAV: namespace.
+*
+* @package   davical
+* @subpackage   caldav
+* @author    Andrew McMillan <andrew@mcmillan.net.nz>
+* @copyright Morphoss Ltd - http://www.morphoss.com/
+* @license   http://gnu.org/copyleft/gpl.html GNU GPL v2 or later
+*/
+dbg_error_log('DELTICKET', 'method handler');
+require_once('DAVResource.php');
+
+if ( ! $request->HavePrivilegeTo('DAV::unbind') && $request->ticket->owner() != $session->principal_id ) {
+  $request->NeedPrivilege('DAV::unbind')
+}
+
+if ( ! isset($request->ticket) ) {
+  if ( isset($_GET['ticket']) || isset($_SERVER['HTTP_TICKET']) ) {
+    $r = new DAVResource($request->path);
+    if ( ! $r->Exists() ) {
+      $request->PreconditionFailed(404,'not-found');
+    }
+    else {
+      $request->PreconditionFailed(412,'ticket-does-not-exist','The specified ticket does not exist');
+    }
+  }
+  else
+    $request->MalformedRequest('No ticket specified');
+}
+
+$qry = new AwlQuery('DELETE FROM access_ticket WHERE ticket_id=:ticket_id', array( ':ticket_id'   => $request->ticket->id() ) );
+if ( $qry->Exec('DELTICKET', __LINE__, __FILE__) ) {
+  $request->DoResponse( 204 );
+}
+$request->DoResponse( 500 );