A relative positioning system enabling {HEAD ~ a user} to return to {TAIL ~ a starting position} or some other point on the users path 
to return to
A relative positioning system enabling { HEAD ~ a user } to return to { TAIL ~ a starting position } or some other point on the users path
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH