Easily offended? Don't read this mofo

There's been a lot of talk in these parts about Texas Gov. Rick Perry's comment to a reporter, accidentally caught on mike: "Adios, mofo."

Now, not everyone knows what "mofo" refers to (shorthand for "motherfucker").

And it prompted a discussion on proper style for the word: Mofo? Mo-fo? Mo'fo?

None of my dictionaries at work could help. It is in the online Urban Dictionary as "mofo," but, like Wikipedia, that's not exactly an authoritative source.

But this Language Log entry sheds some light:

For those foreign readers whose command of American slang is incomplete, mofo is a conventional orthographic representation for a slurred fast-speech rendition of "motherfucker". The first two citations in the OED are

1967 H. S. THOMPSON Hell's Angels 33 The "Mofo" club from San Francisco.
1970 R. D. ABRAHAMS Positively Black vi. 154 Soul is walkin' down the street in a way that says, "This is me, muh-fuh!"

At least, mofo started out that way -- I think it's now taken on its own spelling pronunciation, in the style of tsk and phooey and other such orthographic expedients.

The entry is more about the FCC than mofo, and Mark Liberman continues:

Anyhow, I wonder whether the FCC will fine KTRK-TV $500,000 for each airing of Gov. Perry's valediction, as the law apparently calls on them to do:

(link) ...the term 'profane', used with respect to language, includes the words `shit', `piss', `fuck', `cunt', `asshole', and the phrases `cock sucker', `mother fucker', and `ass hole', compound use (including hyphenated compounds) of such words and phrases with each other or with other words or phrases, and other grammatical forms of such words and phrases (including verb, adjective, gerund, participle, and infinitive forms).'

If so, I wonder whether the station will send the governor the bill. This would be the next logical step in what Stuart Benjamin called the FCC's "fucking brilliant regulatory strategy".

Most news outlets have gone with the mofo spelling, although I've seen a couple mo-fos.