The movie has very VERY VERY VERY strong language. It originally was rated NC-17 for language only.
People talk about sex VERY VERY VERY detailed, with references to necrophilia and transgenders, but nothing is shown. Not even boobs.
I usually count sex and language as a reason for 12 only, nothing more, but in this case i would say the movie is filled with it. You may can not imagine it but the worst thing is when (SPOILER:) a person finds out she accidentally had sex with a dead person (END OF SPOILER).
Also we hear highly philosophic talk aboutr almost anything, but it also includes sex talk, and not just the usual things you hear.
The movie is not distiurbing, frightning or violent.
This black comedy is a masterpiece (i knew i said that about almost every movie i talked about in my last reviews, but it's true!) and it is the best movie Kevin Smith did. All of the others are average, but he can be proud of this one.
(Suiable for viewers 15 and up, not recommended under this age)