This question already has an answer here:
"It would have needed an exceptionally strong Confundus Charm to bamboozle that goblet into forgetting that only three schools compete in the tournament... I'm guessing they submitted Potter's name under a fourth school, to make sure he was the only one in his category..."
— Alastor Moody
I know this is a seemingly unimportant detail, but it has bothered me ever since I first read the book years and years ago. What was the name of the fake school that was written on the slip of paper to assure Harry would be picked? Has this ever been revealed?