What qualifies as obscene on fluther for moderation standards?

Details, real question at [edit] toward the end:

So I got [mod]ed for a comment which was… quite possibly obscene, but it was in a social [NSFW] topic and I did cross out & whisper the questionable part.

I think it was not just the use of the f-word twice but the way (sexually explicit humor… involving Jesus) I used it twice. But it was crossed out and whispered, and in a social [NSFW] topic… And it was only a small (literally) part of my comment which was actually pertinent to the discourse.

“Response moderated (Obscene)”

What makes something obscene on fluther (for future reference)?

Thanks,
and I don’t blame the party who moderated me, just curious!

PM if it can’t be said without getting moderated for being (Obscene). Cheers.