In short, pg-13. Swearing/violence/gore and the like is held to a fairly lenient standard-no reason to censor "crude" language per se.
Sexually explicit is a different story. Keep it clean, as in no detailed descriptions. Let me quote from that link...
I don't have a problem with adult themes in IC threads if they're presented tastefully and maturely, but I will ask that all blatant cybersex be kept to private messaging. Cybersex typically involves fast back-and-forth sexual exchanges.