A first on disc position is related to {TAIL ~ an innermost position} within {HEAD ~ the second data recorded region} 
A first on disc position is related to { TAIL ~ an innermost position } within { HEAD ~ the second data recorded region }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD