So yeah, I'm a noob, I wanted to use AR codes for Animal Crossing gamecube, but I've been hearing of this thing called the (M) code. So..... what is it?
I guess it's a master code. The game might have some protection against cheats and memory manipulation. I think those master codes disable that protection. Basically you will need to use that code as 1st code, and then add whatever code you want to use.