The mask generated from {HEAD ~ the most significant bits section} of the pointer includes bits corresponding to {TAIL ~ various regions} of the output mask 
The mask generated from { HEAD ~ the most significant bits section } of the pointer includes bits corresponding to { TAIL ~ various regions } of the output mask
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH