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