Social: vbite
CNoArg: You bare your fangs.
ONoArg: $n bares $s fangs and peers around nonchalantly.
CFound: You sensually brush $N's neck with your lips before sucking $S blood!
OFound: $n softly brushes $N's neck with $s lips, and then BITES!
VFound: $n bites your neck! Ouchhhh!
CAuto : Now, if you could bite your own neck..I'd worry.
OAuto : $n is in danger of hurting $mself.
Not "extreme sexual content", just "sexually explicit". It is still subjective, but personally I think it's much easier to judge consistently if it's a simple yes/no.
Defining "extreme violence" is also going to be difficult, but as almost every mud includes violence you could use it to refer to games that take it a clear step further.
I think it's also important to decide whether these will be options the mud owner can choose to click (i.e., based on their own opinion), or whether they'll be enforced by some sort of auditing group.
But some muds take it a step further. Some of the violence in my own game can be very graphic, for example (I could provide some examples if you wish).
I'd suggest basing it primarily on coded support, and secondarily on policy. As I mentioned before, the GodWars codebase has a very explicit xsocial system (including coded support for pregnancy and childbirth). In other muds, mudsex via emotes is considered a 'normal' activity, and I'd tend to consider those "sexually explicit" as well.
I'm not so fond of DavidHaley's suggestion that "For sexual content, "light" might mean kissing and petting", as that would include every mud with a "kiss" social, even if you were to ignore the "emote" command.
Agreed (don't forget coffee and beer, either). On the other hand, a modern day mud where the players could inject themselves with heroin and/or sell it to teenager MOBs should probably have some sort of adult classification.
I don't think you'd have a problem, particularly if it's made clear that the listing information is just a subjective best-guess. Likewise, I can't see someone suing you for advertising an "extended class selection" when you've actually only got 4 classes.