Actually, I meant more if there's a spell we use in the RP that does not exist in the series. So say if we want a spell to turn something into a rabbit, which does not exist in the series (I've checked, while there is transfiguration for every animal, they don't name a lot of speicific ones for every animal, just one for furrets, rats and birds). It'd be a spell we should assume be taught in class, so everyone should be able to use it if they're at the right year to learn it.
But yeah, if someone makes up a spell that even in our RP is new and has never been used (example if Kiku makes a spell to make a hologram of characters in his manga appear), then that should be added too. Not really picky on what spells we add as long as they've never appeared in the books.