"Fraternity", please. You wouldn't call a sorority a "sore", would you? You wouldn't call your country a . . . yeah, I'll drop it there.
I am going to go out on a limb and say the number of people at Hacker News who pledged is probably small.
Someone else posted "You wouldn't call your sorority ..." but that's just not how the joke goes. Sorry. Gotta do it. I'm telling the joke. Braced for downvotes.
"You wouldn't call your country a..."
And then I realized, that's the first or second half of the joke that got flagkilled :)
I never, ever understood why people get so fucking offended when someone calls a fraternity a frat. It doesn't matter. It just doesn't matter.