Identifying method for points on map using reduced reference information

摘要

The method involves dividing the map into a number of map zones according to a predetermined co-ordinate system and the selected zones according to predetermined criteria that selected zones will be given. The map zones are then allocated a unique identification code. The code contains first and second code groups, each second code group having fewer digits than the first code group of code. When allocating the unique codes allocation of a code of the second group to the selected zones takes place.