queueing {HEAD ~ means} for storing {TAIL ~ data requests} to said main memory means by a requesting processor and for storing data to be returned to a requesting processor 
for storing
queueing { HEAD ~ means } for storing { TAIL ~ data requests } to said main memory means by a requesting processor and for storing data to be returned to a requesting processor
OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH