The (in)famous A86/A386 assembler claimed to use this technique to identify code produced with it. As far as I know, it was just a simple inversion of reg-reg ModRMs depending on the register values being used, although I didn't test it too exhaustively.
Speaking of things with the same names, what happened to Linux a386 and what the heck was it even? I can't find a link nowadays, but it was something like User Mode Linux, but not really.
