A system 9, wherein the plurality of pieces of mail includes at least one of {HEAD ~ a plurality} of {TAIL ~ letters} and a plurality of flats 
A system 9 , wherein the plurality of pieces of mail includes at least one of { HEAD ~ a plurality } of { TAIL ~ letters } and a plurality of flats
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH