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