There are two end portions on opposite sides of {HEAD ~ the middle portion} of {TAIL ~ the PAN}, and at least one of the end portions remains static during the transaction process 
There are two end portions on opposite sides of { HEAD ~ the middle portion } of { TAIL ~ the PAN } , and at least one of the end portions remains static during the transaction process
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH