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