diff --git a/tests/43session.tests b/tests/43session.tests
index c9648e33b..e10de9e62 100644
--- a/tests/43session.tests
+++ b/tests/43session.tests
@@ -37,6 +37,10 @@ PLANNED "basic placement properties" PlacementBasic_test <<END
 END
 
 
+PLANNED "object identity" PlacementObjectIdentity_test <<END
+END
+
+
 TEST "hierarchical placement types" PlacementHierarchy_test <<END
 out: sizeof\( .+ \) =  [0-9]{2}
 out: Placement.+mobject.+test.+TestSubMO1.+. use-cnt=1 .*
diff --git a/tests/components/proc/mobject/placement-object-identity-test.cpp b/tests/components/proc/mobject/placement-object-identity-test.cpp
new file mode 100644
index 000000000..dad475fb0
--- /dev/null
+++ b/tests/components/proc/mobject/placement-object-identity-test.cpp
@@ -0,0 +1,159 @@
+/*
+  PlacementObjectIdentity(Test)  -  object identity for placements into the session
+ 
+  Copyright (C)         Lumiera.org
+    2010,               Hermann Vosseler <Ichthyostega@web.de>
+ 
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 2 of the
+  License, or (at your option) any later version.
+ 
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+ 
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ 
+* *****************************************************/
+
+
+#include "lib/test/run.hpp"
+#include "lib/lumitime.hpp"
+#include "proc/asset/media.hpp"
+#include "proc/mobject/mobject.hpp"
+#include "proc/mobject/mobject-ref.hpp"
+#include "proc/mobject/placement.hpp"
+#include "proc/mobject/placement-ref.hpp"
+#include "proc/mobject/session/placement-index.hpp"
+#include "proc/mobject/session/session-service-mock-index.hpp"
+#include "proc/mobject/session/clip.hpp"
+#include "proc/mobject/explicitplacement.hpp"
+//#include "proc/mobject/test-dummy-mobject.hpp"
+//#include "lib/test/test-helper.hpp"
+
+//#include <iostream>
+//
+//using std::string;
+//using std::cout;
+//using std::endl;
+
+
+namespace mobject {
+namespace test    {
+  
+  using lumiera::Time;
+  using session::Clip;
+  
+  using session::SessionServiceMockIndex;  
+  
+
+  
+  /***************************************************************************
+   * @test verify correct handling of object identity. Create test objects,
+   *       add placements to a dummy index/session, then create PlacementRef
+   *       and MObjectRef handles. Finally do cross comparisons.
+   *       
+   * @todo WIP-WIP to be written...  TICKET #517
+   *        
+   * @see  mobject::PlacementRef_test
+   * @see  mobject::MObjectRef_test
+   */
+  class PlacementObjectIdentity_test : public Test
+    {
+      
+      typedef Placement<MObject>        PMObj;
+      typedef Placement<Clip>           PClip;
+
+      typedef PlacementMO::ID       PMObjID;
+      typedef PlacementMO::Id<Clip> PClipID;
+
+      
+      virtual void
+      run (Arg) 
+        {
+          
+          // create data simulating a "Session"
+          PMObj  pClip1 = asset::Media::create("test-1", asset::VIDEO)->createClip();
+          PMObj  pClip2 = asset::Media::create("test-2", asset::VIDEO)->createClip();
+          
+          // set up a tie to fixed start positions
+          pClip1.chain(Time(10));
+          pClip2.chain(Time(20));
+          
+          ASSERT (pClip1->isValid());
+          ASSERT (pClip2->isValid());
+          ASSERT (2 == pClip1.use_count());  // one by the placement and one by the clip-Asset
+          ASSERT (2 == pClip2.use_count());
+          
+          ////////////////TODO direct comparisons
+          ////////////////TODO direct comparisons
+          
+          UNIMPLEMENTED ("verify proper handling of object identity");
+          
+#if false  //////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET 517  !!!!!!!!!!!!!!
+          // Prepare an (test)Index
+          PPIdx index = SessionServiceMockIndex::install();
+          PMO& root = index->getRoot();
+          
+          // Add the Clips to "session"
+          PMObjID clip1ID = index->insert (pClip1, root);
+          PMObjID clip2ID = index->insert (pClip2, root);
+
+          ////////////////TODO compare ids
+          ////////////////TODO compare ids
+
+          
+          // extract various kinds of IDs and refs
+          PMObj &         rP1 (pClip1);
+          PMObj const&    rP2 (pClip2);
+          PMObj::ID       id1 = pClip1.getID();
+          PMObj::Id<Clip> id2 = pClip2.getID();
+          LumieraUid luid = id1.get();
+          
+          PlacementRef<Clip>    ref1 (id1);
+          PlacementRef<MObject> ref2 (pClip2);
+          
+          MORef<Clip> rMO;
+          ASSERT (!rMO);                    // still empty (not bound)
+          
+          // activate by binding to provided ref
+          rMO.activate(refObj);
+          ASSERT (rMO);                     // now bound
+          
+          ///TODO access Placement, fetch ID
+          
+          // re-link to the Placement (note we get the Clip API!)
+          Placement<Clip> & refP = rMO.getPlacement();
+          ASSERT (refP);
+          ASSERT (3 == refP.use_count());
+          ASSERT (&refP == placementAdr);   // actually denotes the address of the original Placement in the "session"
+          
+          ExplicitPlacement exPla = refP.resolve();
+          ASSERT (exPla.time == start);     // recovered Placement resolves to the same time as provided by the proxied API
+          ASSERT (4 == refP.use_count());   // but now we've indeed created an additional owner (exPla)
+          ASSERT (4 == rMO.use_count());
+          
+          
+          ////////////////TODO now do the cross comparisons
+          ////////////////TODO now do the cross comparisons
+          
+          
+          ///clean up...
+          index.reset();
+
+#endif ////////////////////////////////////////////////     ////////////////////////////////////////////////////TODO to be written........!!!!!
+        }
+      
+      
+    };
+  
+  
+  /** Register this test class... */
+  LAUNCHER (PlacementObjectIdentity_test, "function session");
+  
+  
+}} // namespace mobject::test