{HEAD ~ A folder} that is a member of {TAIL ~ a federated folder} can also be a federated folder 
{ HEAD ~ A folder } that is a member of { TAIL ~ a federated folder } can also be a federated folder
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH