Just go into your profile, change your display name and picture, and just act like you're in costume until the 31st when we reveal who we actually are! We start on the 25th and end on Halloween, and it's unofficial at this point. We'll still have fun, and Notebook rules of conduct apply. This is for those who are interested, though you could continue RPs and whatnot if you tell the other participants who you are to limit confusion. It's meant to be a silly, fun thing we do (first of its kind, as far as I'm aware), and we just talk and act like our costumes.
It's a masquerade party, but we don't have to interact like normal human beings or worry about missing out on the punchbowl!