I am both posters, pardon the confusion. I don't want to pretend to be the authority for what's acceptable, but it seems people here prefer if the pokemon you bring aren't too op. So a smattering of ou pokemon and down.
However I remember a time when sometimes people would decide on a theme before multi battles, like monotype where everyone would bring pokemon of the same type, or tiered battles so people could pick from certain pools like ubers or RU pokemon. I have no prejudice for rules, but I do believe it's better when those battling have similar expectations. Your question is considerate.