GameID

The GameID on Nintendo platforms is a sequence of 4 (6 with company code) characters derived from the end of a title's Title ID, used to represent that title in an abbreviated form.

On the GameCube and Wii, its structure is as follows:

First character	Code representing title type (e.g. G for GameCube titles, R (Revolution) for early Wii disc titles, W for WiiWare titles)
Middle two characters	Unique title/game ID (e.g. "MG" for Super Mario Galaxy)
Last character	Region encoding (e.g. E for Americas/Middle East/SEA, J for Japan/Taiwan/Hong Kong)
Subsequent two characters	Company code (e.g. 01 for Nintendo)

An example of a Wii disc title GameID would be "RMGE01" for Super Mario Galaxy, with "R" representing an early-run Wii disc title, "MG" being the unique game code, "E" representing the Americas region, and "01" being the company code.