{HEAD ~ These parts} are identified with reference to {TAIL ~ the position} of the tool shown in FIGS 1 and 3 
{ HEAD ~ These parts } are identified with reference to { TAIL ~ the position } of the tool shown in FIGS 1 and 3
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH