GPS ID, MapID, FID, PID, RgnID ,VenID
GPS ID - Unique identifier for a hardware device.
FID – Family ID value – Unique identifier for map creator. FID is NOT MapId.
PID - Product Code - Unique value for product identification. Usually value 1 is used.
Region Code - Each product can consist of several separate regions. There could be up to 255 regions within a single product, each region can have its own unlock code.
Subregion ID - Additional identifier for unlock code, sometimes it's called vendor ID.
Garmin unlock codes are created basing on GPS ID, FID, PID, region and subregion.
Map ID - Identifier for a single tile of a map. This number must be unique among all maps in GPS.
A GPS receiver will ignore a second tile with the same MapID.
Each Garmin .img tiles have their own map ID, other then FID and PID.Each tile has an unique mapname.
How is MapID created?
MPC user gets the MapID inside license,FID too.
In cGPSmapper or Mapwel is the user who has to define MapID for each tile.
The MapID (8 digits number) switch defines what the actual filename for each tile is. Tiles usually have filenames that increment by 1 each time.
Just tiles have a MapID? Or other subfiles too?
Only tiles have a MapID, but can find the MapID in other subfiles, MMR file has MapID from its connected tile, MDR (index) contains all MapIDs from mapset, TRF, JCV have mapIDs from connected tiles.
There is a relation between FID and MapID?
There could be created a formula to compute MapID range basing on FID value, but this can be true for some Garmin maps only.