It's popular on Invisionfree/Proboards/Jcink/otherboardh
Personally, I find it does the job perfectly: the 'job' meaning what is and isn't allowed in a game, concerning language, sexual content and violence. The order is Language, Sexual content, Violence, and is colour-coded for our convenience. It's ranked in stages: 0, 1, 2, 3. You rate your game according to what levels are acceptable. Green 0 is the lowest level, whilst orange 3 is the highest. It's a simple matter of clicking 3 tick-boxes, one per category, and copy/pasting the supplied banner code into your game ad- or wherever you think is best to display your rating.
When I come across a game rated 2-2-3, 3-2-3 or 2-1-2, I understand what the game will entail. I either dive into the game links, or I hit the Back button.
On the other hand, with a typical game that's proclaimed as R, PG, NC-17... What constitutes an R or MA rated movie (or RPG, in this case) changes with each individual game. To me, R means zero censorship. That said, I'm somewhat lost when I find a game that's R, but I'm not permitted to write gore, swear, or explore substance abuse. This should've effectively lowered the R rating.
I've long since learned that R simply means that you have to be 18yo in order to join- the rules themselves may require players to keep profanity and graphic violence to a minimum.
What do you use to rate your game? Are you interested in the Universal RPG Rating system?
I am curious, and I want this to be a constructive mission. At the end of the day, I'd like to have a tally of yes and no answers. I do not want personal life stories; a simple yes or no is good enough! The feedback that will be most helpful to me are answers like "Yes, I use this system because it's concise and crystal clear, instead of opting for the MPAA system which I think is inappropriate for role-play." , as opposed to "The MPAA system sucks! I like ______."