It's good that you ruled out the water decorations because they were out of place.

@kindlypatrick: Ah, that makes sense! Thanks for clearing that up!

ahh that's what was confusing me, cause I didn't think Light created these robots lol

@kindlypatrick the greatest villain in megaman

The R stands for Rozner Labs, the developer of the DOS games

@ZharK: In Japan, Dr. Light is known as Dr. Right, so the letter plate here implies that he built Volt Man (and, presumably, the other two Robot Masters in the game, Sonic Man and Dyna Man). Upon skimming through Mega Man DOS's page on Mega Man Knowledge Base, however, there doesn't seem to be any evidence that he did build them, and upon looking at the original level map for Volt Man's stage, there isn't even a letter plate anywhere.

It could've been included here as a nod to the fact that in the first NES game, all the Robot Masters *were* built by Dr. Light (and Wily, too, of course). Again, there's no evidence of it, but maybe the same applies to the Robot Masters of the first DOS game as well?

R?