Not absurd at all! That was apparently me missing yet another thing in the U.I. that wasn't caught in the pre-promotion "is that everything?" check. I apologize.
For the purposes of this community we will define crack as: any fanwork (fic, art, etc) that is centered around an insane pairing, a completely ridiculous scenario, or a combination of both.
By saying that we take the crack! part seriously, we mean that stories should have a somewhat logical progression to them (it can't be completely logical if it's based on the inane and absurd, can it?) and even though they are written with an attempt at seriousness, the stories themselves are so out there and it is virtually impossible to take them seriously.
To be vulgar about it - if you read a story and your first thought is "Damn, that was fucked up!" then you probably found a crack!fic.