Reply from Agony Uncle
A “Black Tie” event means an event that requires formal dressing. It would be rude and improper for gentlemen to dress in your usual jacket.
One should have to wear tuxedo. This name originates from the outfit that made its appearance first in 1886 in New York’s Tuxedo Park. The Europeans on the other hand calls it the smoking jacket.
“Black tie” means a bow tie either in black or other colors (never white). The pants must be pleated. One must never wear belt only cummerbund. The corresponding for ladies would be evening gown and never working clothes or party dress. Attention must be paid to appropriate accessories and purse.