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