In {HEAD ~ some cases}, multiple computer systems may be connected, each residing at a node of {TAIL ~ a network} 
In { HEAD ~ some cases } , multiple computer systems may be connected , each residing at a node of { TAIL ~ a network }
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL