One)) No being too OP.  You are limited to having the powers bestowed upon you by your wand, end of story. "Powers" bestowed to you by certain circumstances (i.e. being turned into a werewolf or a vampire) are alright, just make sure you clear it with me first. I don't want hundreds of vampires running around.
Two)) Please use third person, I don't care if you use present or past tense. I find it hard to follow when someone jumps between first and third person, or uses present tense. Also both are annoying. Lol
Three)) Hate the OC, not the person behind them. Honestly I hate it when people rag on someone for whatever reason. So be nice to each other please.
Four)) No bullying OOC. If your character is a Slytherin (and also a prick, not that I'm saying all of them are, though) that's fine, just don't bully outside of that.
Five)) When talking OOC, use parentheses: ()[]{} or any variation you wish, as long as it's clear that it's you talking out of character.
Six)) No Godmodding/playing God. Let others decide the fate of their characters . Unless, of course, I come up with a huge plot twist.
Seven)) Please make a boy and a girl.
Eight)) For the LOVE OF GOD if you swear, please please censor it. I don't wanna get reported
Nine)) Please wait until I've accepted your form before roleplaying. Otherwise I'll be like 'Wait, who tf is this?' And we don't want that lol

That is all for now!