I think it should be around PG-13 cause if not stated, then more mature rps will come out. People might get offended. We *coughcough the rp comunity cough cough* Don't want that.
I thought the rules were mentioning PG-13 limit. I'm not really checking the RP section, but if something is not right, please link me to the thread in question, I'll look into it.