I've taken the liberty to copy here the Guardian's style guide entry on swearwords:

swearwords

We are more liberal than any other newspapers, using language that most of our competitors would not. The statistics tell their own story: the word “fuck” (and its variants) appeared 705 times in the Guardian in the 12 months to April 2010, with a further 269 mentions in the Observer. (The figures for other national newspapers were as follows: Independent 279, Independent on Sunday 74, Times 3, Sunday Times 2, all other papers 0.) The figures for the C-word, still regarded by many people as taboo, were: Guardian 49, Observer 20, Independent 8, Independent on Sunday 5, everyone else 0.

Even some readers who agree with Lenny Bruce that “take away the right to say fuck and you take away the right to say fuck the government” might feel that we sometimes use such words unnecessarily, although comments in response to Guardian Style’s blogpost on the subject were overwhelmingly in support of our policy.

The editor’s guidelines are as follows:

First, remember the reader, and respect demands that we should not casually use words that are likely to offend.

Second, use such words only when absolutely necessary to the facts of a piece, or to portray a character in an article; there is almost never a case in which we need to use a swearword outside direct quotes. The use of swearwords in furniture, especially headlines, should also be avoided unless an editor deems it absolutely necessary.

Third, the stronger the swearword, the harder we ought to think about using it.

Finally, never use asterisks, or such silliness as b------, which are just a cop-out, as Charlotte Brontë recognised: “The practice of hinting by single letters those expletives with which profane and violent people are wont to garnish their discourse, strikes me as a proceeding which, however well meant, is weak and futile. I cannot tell what good it does – what feeling it spares – what horror it conceals”

Grand!