Federated folders can contain objects or members that are documents and {HEAD ~ folders} stored in {TAIL ~ other heterogeneous datastores} 
stored in
Federated folders can contain objects or members that are documents and { HEAD ~ folders } stored in { TAIL ~ other heterogeneous datastores }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL