It maintains all usages of "fuck," be it expletive, noun, verb, or adjective.
Popularized by Battlestar Galactica in 1978 with the original spelling of "frack," changed to the current spelling in the re-imagined miniseries in 2003.
Noun - You're nothing but a worthless frak!
Verb - Anyone want to frak? I've got half an hour?
That's just frakking great... now the Cylons know exactly where we are!