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