What to wear to a "Black-Tie Event"

Usually we see this on high profile invitations. For women it does not mean wear black but it means wear a formal long evening gown or a formal knee-length cocktail dress.
For men it traditionally means a suit with an evening dinner jacket, white shirt and a black bow tie. These days the colours are not as strict but a bow tie and dinner jacket are required. black tie cocktail dress

Dress by Eric Mandeya
Event: Harare Metropolitan Ball 2017
Event Venue: Meikles Hotel