diff --git a/inc/caldav-PROPFIND.php b/inc/caldav-PROPFIND.php
index ddc6bcac..21a28e77 100644
--- a/inc/caldav-PROPFIND.php
+++ b/inc/caldav-PROPFIND.php
@@ -84,7 +84,7 @@ function add_proxy_response( $which, $parent_path ) {
   $collection->created = date('Ymd\THis');
   $collection->dav_etag = md5($c->system_name . $collection->dav_name . implode($proxy_group) );
   $collection->proxy_for = $proxy_group;
-  $collection->resourcetypes  = sprintf('<DAV::collection/><http://calendarserver.org/ns/:calendar-proxy-%s/>', $which);
+  $collection->resourcetypes  = sprintf('<DAV::principal/><DAV::collection/><http://calendarserver.org/ns/:calendar-proxy-%s/>', $which);
   $collection->in_freebusy_set = 'f';
   $collection->schedule_transp = 'transp';
   $collection->timezone        = null;
diff --git a/testing/tests/regression-suite/0003-Mulberry-1.result b/testing/tests/regression-suite/0003-Mulberry-1.result
index 639bf4cd..5b5a9a42 100644
--- a/testing/tests/regression-suite/0003-Mulberry-1.result
+++ b/testing/tests/regression-suite/0003-Mulberry-1.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "6224e345c323da0dfc00689c21171119"
-Content-Length: 2254
+ETag: "e6d93b26332f9761d7f7c0b312b67203"
+Content-Length: 2290
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -71,6 +71,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <getcontenttype>httpd/unix-directory</getcontenttype>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-read/>
     </resourcetype>
@@ -90,6 +91,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <getcontenttype>httpd/unix-directory</getcontenttype>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0005-Mulberry-1.result b/testing/tests/regression-suite/0005-Mulberry-1.result
index 4d8a485a..b60d93ad 100644
--- a/testing/tests/regression-suite/0005-Mulberry-1.result
+++ b/testing/tests/regression-suite/0005-Mulberry-1.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "966d4f7d769690fca393be5ba814e8a2"
-Content-Length: 2655
+ETag: "2ebe7538bcf8ebd276b16f11e23fe089"
+Content-Length: 2691
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -90,6 +90,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <getcontenttype>httpd/unix-directory</getcontenttype>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-read/>
     </resourcetype>
@@ -109,6 +110,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <getcontenttype>httpd/unix-directory</getcontenttype>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0240-Moz-PROPFIND.result b/testing/tests/regression-suite/0240-Moz-PROPFIND.result
index 616de376..714c2c12 100644
--- a/testing/tests/regression-suite/0240-Moz-PROPFIND.result
+++ b/testing/tests/regression-suite/0240-Moz-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "fd17acf5fe9ad6e6612323ef680b3d10"
-Content-Length: 2601
+ETag: "e47dc7e426b489d5b895ae49c27f9d18"
+Content-Length: 2637
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -90,6 +90,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <getcontenttype>httpd/unix-directory</getcontenttype>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-read/>
     </resourcetype>
@@ -109,6 +110,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <getcontenttype>httpd/unix-directory</getcontenttype>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0502-iCal-PROPFIND.result b/testing/tests/regression-suite/0502-iCal-PROPFIND.result
index d0f081c4..d14ccd80 100644
--- a/testing/tests/regression-suite/0502-iCal-PROPFIND.result
+++ b/testing/tests/regression-suite/0502-iCal-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "e3f59c55883b61b4390fd7ffbe74644b"
-Content-Length: 3649
+ETag: "a6b5a79175d3f6a77c40f55e50783e55"
+Content-Length: 3685
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -134,6 +134,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <displayname>/user1/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-read/>
     </resourcetype>
@@ -154,6 +155,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <displayname>/user1/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0522-iCal-PROPFIND.result b/testing/tests/regression-suite/0522-iCal-PROPFIND.result
index e41c2510..695b8208 100644
--- a/testing/tests/regression-suite/0522-iCal-PROPFIND.result
+++ b/testing/tests/regression-suite/0522-iCal-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "fb3fbd1d4d0cc1e1926d0291a2be17a8"
-Content-Length: 4076
+ETag: "f2de15142ea3906e3616b81150a746b5"
+Content-Length: 4112
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -130,6 +130,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"19a2e9eecca4a20bb93c23c0ab653d77"</C:getctag>
     <displayname>/user2/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -153,6 +154,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"f9ade6a8d81cbc6a7a7b932981955bb4"</C:getctag>
     <displayname>/user2/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0524-iCal-PROPFIND.result b/testing/tests/regression-suite/0524-iCal-PROPFIND.result
index 1aee45e2..7f49a673 100644
--- a/testing/tests/regression-suite/0524-iCal-PROPFIND.result
+++ b/testing/tests/regression-suite/0524-iCal-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "45a0a8b922545d0793e9b0b9d10726fe"
-Content-Length: 6054
+ETag: "b7d922855233223a02e6ae2b26b1e384"
+Content-Length: 6090
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -126,6 +126,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"ccdfbfa2e7ee6c47d3ea8f134d415b89"</C:getctag>
     <displayname>/manager1/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -163,6 +164,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"ff25f14bac404c0aae34b5e75618d479"</C:getctag>
     <displayname>/manager1/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0525-iCal-PROPFIND.result b/testing/tests/regression-suite/0525-iCal-PROPFIND.result
index 7f95c067..ee40da1b 100644
--- a/testing/tests/regression-suite/0525-iCal-PROPFIND.result
+++ b/testing/tests/regression-suite/0525-iCal-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "87bca499488e3f4a217d3c2585b17ad5"
-Content-Length: 1459
+ETag: "5712eb30f86b6a9755a688c43b4bb763"
+Content-Length: 1477
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -15,6 +15,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"ccdfbfa2e7ee6c47d3ea8f134d415b89"</C:getctag>
     <displayname>/manager1/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0532-iCal4-PROPFIND.result b/testing/tests/regression-suite/0532-iCal4-PROPFIND.result
index 1ce1ec23..7c3b7bab 100644
--- a/testing/tests/regression-suite/0532-iCal4-PROPFIND.result
+++ b/testing/tests/regression-suite/0532-iCal4-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "2f6bc2532047e694057b7ec66bd80b65"
-Content-Length: 15568
+ETag: "b61898a70b17314ab1368136b7899458"
+Content-Length: 15604
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -544,6 +544,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"abad5538c4aa570cc54b6ff0d36a4565"</C:getctag>
     <displayname>/user1/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -615,6 +616,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"04ba2c2164225fb5abce13f2c523b6c7"</C:getctag>
     <displayname>/user1/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0547-iCal4-PROPFIND.result b/testing/tests/regression-suite/0547-iCal4-PROPFIND.result
index ae892948..f9c50fb6 100644
--- a/testing/tests/regression-suite/0547-iCal4-PROPFIND.result
+++ b/testing/tests/regression-suite/0547-iCal4-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "84f6ab86e65ad459a930d65cf80aad20"
-Content-Length: 17999
+ETag: "d53571128cc728cde4c63151596715bf"
+Content-Length: 18035
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -621,6 +621,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"abad5538c4aa570cc54b6ff0d36a4565"</C:getctag>
     <displayname>/user1/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -703,6 +704,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"04ba2c2164225fb5abce13f2c523b6c7"</C:getctag>
     <displayname>/user1/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0548-iCal-PROPFIND.result b/testing/tests/regression-suite/0548-iCal-PROPFIND.result
index 0a554289..58274551 100644
--- a/testing/tests/regression-suite/0548-iCal-PROPFIND.result
+++ b/testing/tests/regression-suite/0548-iCal-PROPFIND.result
@@ -4,8 +4,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "d148cedddc356b211c308738c99d6888"
-Content-Length: 27711
+ETag: "aec265205859386bcdf4b58ce5820905"
+Content-Length: 27747
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -958,6 +958,7 @@ Content-Type: text/xml; charset="utf-8"
      <href>/caldav.php/user1/</href>
     </owner>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -1097,6 +1098,7 @@ Content-Type: text/xml; charset="utf-8"
      <href>/caldav.php/user1/</href>
     </owner>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0553-iPhone-PROPFIND.result b/testing/tests/regression-suite/0553-iPhone-PROPFIND.result
index a1401e5d..f9bee606 100644
--- a/testing/tests/regression-suite/0553-iPhone-PROPFIND.result
+++ b/testing/tests/regression-suite/0553-iPhone-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "7513417f3b7f77337d0ae47039f47f5a"
-Content-Length: 12598
+ETag: "ae6b5e0b9194d560b5b73b951f256b6e"
+Content-Length: 12634
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -467,6 +467,7 @@ Content-Type: text/xml; charset="utf-8"
     <displayname>/user1/calendar-proxy-read/</displayname>
     <C:getctag>"abad5538c4aa570cc54b6ff0d36a4565"</C:getctag>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -527,6 +528,7 @@ Content-Type: text/xml; charset="utf-8"
     <displayname>/user1/calendar-proxy-write/</displayname>
     <C:getctag>"04ba2c2164225fb5abce13f2c523b6c7"</C:getctag>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0554-iPhone-PROPFIND.result b/testing/tests/regression-suite/0554-iPhone-PROPFIND.result
index a1401e5d..f9bee606 100644
--- a/testing/tests/regression-suite/0554-iPhone-PROPFIND.result
+++ b/testing/tests/regression-suite/0554-iPhone-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "7513417f3b7f77337d0ae47039f47f5a"
-Content-Length: 12598
+ETag: "ae6b5e0b9194d560b5b73b951f256b6e"
+Content-Length: 12634
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -467,6 +467,7 @@ Content-Type: text/xml; charset="utf-8"
     <displayname>/user1/calendar-proxy-read/</displayname>
     <C:getctag>"abad5538c4aa570cc54b6ff0d36a4565"</C:getctag>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -527,6 +528,7 @@ Content-Type: text/xml; charset="utf-8"
     <displayname>/user1/calendar-proxy-write/</displayname>
     <C:getctag>"04ba2c2164225fb5abce13f2c523b6c7"</C:getctag>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0558-iPhone-PROPFIND.result b/testing/tests/regression-suite/0558-iPhone-PROPFIND.result
index 0e15c650..4920b01b 100644
--- a/testing/tests/regression-suite/0558-iPhone-PROPFIND.result
+++ b/testing/tests/regression-suite/0558-iPhone-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "9057a2847bd4becabc777dab5decf806"
-Content-Length: 4549
+ETag: "f572268d68b8a8248e5815aed2fb71b8"
+Content-Length: 4585
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -158,6 +158,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <displayname>/user1/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-read/>
     </resourcetype>
@@ -177,6 +178,7 @@ Content-Type: text/xml; charset="utf-8"
    <prop>
     <displayname>/user1/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C2:calendar-proxy-write/>
     </resourcetype>
diff --git a/testing/tests/regression-suite/0912-Space-PROPFIND.result b/testing/tests/regression-suite/0912-Space-PROPFIND.result
index 6e40dfb1..4e5f5a99 100644
--- a/testing/tests/regression-suite/0912-Space-PROPFIND.result
+++ b/testing/tests/regression-suite/0912-Space-PROPFIND.result
@@ -2,8 +2,8 @@ HTTP/1.1 207 Multi-Status
 Date: Dow, 01 Jan 2000 00:00:00 GMT
 DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule
 DAV: extended-mkcol, bind, addressbook, calendar-auto-schedule, calendar-proxy
-ETag: "4958f56cf9ec116e609399113e3e021e"
-Content-Length: 3633
+ETag: "658053f61e0687f1f65422d691ef980c"
+Content-Length: 3669
 Content-Type: text/xml; charset="utf-8"
 
 <?xml version="1.0" encoding="utf-8" ?>
@@ -107,6 +107,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"7032a440adf6aaab2a81cd3bc214d153"</C:getctag>
     <displayname>/User Six/calendar-proxy-read/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-read/>
     </resourcetype>
@@ -130,6 +131,7 @@ Content-Type: text/xml; charset="utf-8"
     <C:getctag>"d729246362363c87ec3d13d6eaa99efa"</C:getctag>
     <displayname>/User Six/calendar-proxy-write/</displayname>
     <resourcetype>
+     <principal/>
      <collection/>
      <C:calendar-proxy-write/>
     </resourcetype>