A computer implemented method for determining a requested map location includes providing a database holding a plurality of {HEAD ~ map objects} having {TAIL ~ respective descriptors} and loci 
having
A computer implemented method for determining a requested map location includes providing a database holding a plurality of { HEAD ~ map objects } having { TAIL ~ respective descriptors } and loci
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH