I could check first, but thought I'd see if WTF is allowed as a word here. While its an abbreviation of a word we don't allow the WTF has almost become an acceptable phrase.
I see it is allowed, so I won't chastise anyone for it, though I'll try to avoid using it myself. I tried to use it in another forum and saw it was censored.
Just for fun, who remembers when the word spoon was banned? That always caused problems here, but if I have a legacy on this forum it will be for correcting that.