"My guests won't turn up to my event in Black Tie"
Guests of an event usually respect the wishes of the host (especially if you are having a black tie wedding!), and would only "dress down" if they weren't sure what to wear. The Black Tie bookmark dispels any confusion and also acts as a gentle nudge for those considering a less formal option. Remember, the event is usually about YOU, and if you decide that a Black Tie affair is the way to go, your guests will usually respect that wish.
