Over on the Budget Weddings board there's a bride who seems to be a bit confused about what a black tie wedding entails... What do you think the definition of black tie is? What elements make a wedding black tie?
EDIT: If you go to a black tie wedding, what would your expectations be in terms of food, drinks, entertainment, venue, etc.? Would you be upset if your FI or DH rented a tux for the wedding, for example, and those expectations weren't met?