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