The second on {HEAD ~ disc position} is in substantial coincidence with {TAIL ~ an outermost position} within the first data recorded region 
The second on { HEAD ~ disc position } is in substantial coincidence with { TAIL ~ an outermost position } within the first data recorded region
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH