I've recently read two quite "hard core" novels, both by famous authors. One was erotic fiction and one was a thriller which was very violent and gory. At the end I realized something: the F*** word was never used once in either book.
Then, I realized that I don't actually see it a lot in novels, or perhaps the novels I read.
Both the above books had a lot of sh**, damn, freaking, screw, bi**** etc, but not F*** or F***ing and variations.
Is there some unwritten rule about this? Is it seen as very vulgar in novels? Or just unnecessary? Can it put readers off?
Any thoughts would be appreciated.