What are the meanings of "M" and "S"?

Hey everybody,

If there are different saturn images that read as follows:

Chaos Seed (RevA) (10M)
Chaos Seed (RevB) (21M)

..what does that mean in particular? I mean I get the Revision part, but what does M stand for? It can't be Multilanguage, since this is a japanese exlusive and there is not one bit of language other than japanese in this game.

But the revision part is not necessarily bound to this M. It can also stand alone like this:

Rockman X4 (1M)
Rockman X4 (3M)

And then there is also S, for example:

Astal (1S)
Astal (3S)

Can somebody please explain to me what are the meanings behind those different numbers and letters and their possible combination with revisions?


Patron Supporter
The (M) or (S) is how the ring code was produced I take it.

(M) is when the master code was used with a laser. For example: Rockman X4

T-1221GP-01680 3M1 C 78

T-1221GP-01680 1MM1 C 77

(S) is when the master code was stamped or engraved. For example: Astal
1008681019 8/95 3SA3
1008681019 7/95 2SA3
1008681019 6/95 1SA1

source: redump.org