Fic labeling

Hmmm. I've known for a while now that my system for rating my fics is pretty, well, inconsistent and maybe not the best. I generally use the MPAA rating system (PG, R, NC-17, etc.), but that doesn't seem that helpful, considering the MPAA system isn't used everywhere and those ratings aren't always clear anyway. And I'm not the MPAA's biggest fan. So I'm trying to come up with an alternative. I'm thinking AO3's system (General Audiences, Mature, etc.) is pretty good. Maybe I'll adopt that?

Any ideas/thoughts?