Wikipedia
The mapcode system is a spatial reference system (not to be confused with the Denso mapcode system). A mapcode is a code consisting of two groups of letters and digits, separated by a dot. It represents a location on the surface of the Earth, within the context of a separately specified country or territory. For example, the entrance to the elevator of the Eiffel Tower in Paris is “France 4J.Q2”. As with addresses, it is often unnecessary to explicitly mention the country.
The mapcode algorithm defines how a WGS 84 coordinate (a latitude and longitude) can be converted into a mapcode, and vice versa. Mapcodes are supported on over 50,000,000 car navigation devices world-wide. More and more mapping companies are adopting mapcode as a standard.