I've got some fics that are currently part of an unrevealed collection -- I'd like to designate one of them as a safe work, but I don't want to de-anon myself before author reveals. Should I just wait to sign up until afterward?

eta: what is the procedure for offering a fandom that slots under an umbrella tag (with other unrelated works)? I know the request must be canonical, but does the same apply to offers?