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