In some embodiments the tag backscatters {TAIL ~ a combination} of its tag response and {HEAD ~ one or more other codes} 
In some embodiments the tag backscatters { TAIL ~ a combination } of its tag response and { HEAD ~ one or more other codes }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD