NB: This answer tries to answer the more general question, rather than specifically "BrainF*ck"
I'm not sure if the question is about using a profanity or just if adding this language is beneficial. The latter will depend on the type of job you are applying to but as a general rule of thumb (assuming you're a programmer of some sort):
If it's a language that is a bit different and you are proficient in (i.e. makes you stand out) add it.
To address the other question:
Is it ok to use a profanity in a CV if it's the name of a Language / Company / Website (etc.)?
I don't see any issue in this, although of course it will vary from country to country, company to company and person to person. Provided it is clear what it is, it adds to your experience, (and that you're not using just to say "f*ck" on your CV) then it's ok.
Personally, I'd use it as in the title of this post (UK based, tend to apply to more casual small companies). Follow your nose with this one though - judge based on the type of company.
BF is probably ambiguois. For companies you want to avoid swearing go with BrainF.
As many of the comments mentioned, listing Code Golf as a hobby would generally look pretty good on a resume and this is a fairly well established term. Unless you're a complete whizz, specifically at BrainF, just list that.