This section is for discs commonly known as Check
Discs (or sometimes better known as 'silvers' in the game collecting community).
They are discs that are manufactured with early builds of the games for testing
purposes (or to display at conventions or to give to press for early reviews),
or they are the initial batch of discs off the manufacturing line that are then
thoroughly tested one last time to verify there are no manufacturing problems
(or sometimes to catch last-minute bugs).
It seems that if the 4-letter portion Product Code of the disc ends with a T
or X that the disc contains an early Beta build of the game. This might be a
really early build for testing a specific aspect of the game (sometimes with
debug information and special menus that give you powers the player won't normally
have), or it might be pretty much exactly the same as the final retail disc.
If the last letter is an S, that represents a more-or-less finished version
of the game (although there can still be a ver 1.01, 1.02, etc as last minute
changes are made to the game).
The discs vary in appearence from completely blank (thus the term 'silvers'),
to full details about the game, company that made it, date the build was made,
version number, etc... For the most part, if there is anything printed on the
disc, it's just simple black text on a silver disc.
