Sometime stands for Fetish, in some stories/fanfiction.

It’s an acronym standing for Can’t Remember A Fucking Thing. It’s usually used to describe embarrassment at being unable to remember someone (CRAFT moment); going onstage as the lead in the latest theatrical performance and your mind goes completely blank (CRAFT situation); the next morning after a night when you got pissed as a fart and woke up in bed cuddling a traffic cone and a string of fairy lights wound round your prick.

Shortfor the kinky social networking site Fetlife

Commonly used in some parts of the UK to refer to amphetamines.

Fat, but better

Used as a derivative of “fuck”. A PG-13 more or less.

a variant of "fat", which means:
1) noun: the lumps and rolls on a large person's body
2) verb: to be large and possess lumps and rolls