White Tie
White tie is the most formal dress code in Western fashion. Men are expected to wear a black tailcoat, trousers, shoes, and socks; white wing-collared shirt, vest, and bow tie; studs, cufflinks, suspenders, and, if you really want to go wild, a boutonniere. There are no color requirements for women, any old floor-length evening or ball gown will do—long gloves optional. Morning dress is a variation of white tie for events before 6 p.m.; men wear a modified tailcoat called a morning coat, and striped trousers in a muted color, while women may venture slightly shorter with their dresses. These cocktail dresses are great.
Black Tie
Black tie is slightly less rigid, yet amply swanky. For men, black tie calls for a tuxedo jacket (rather than a tailcoat), black bow tie (rather than white), and the option of black vest or cummerbund. Women may opt for a dressy long dress. The pre-evening variant for black tie is called stroller and replaces the man's tux jacket with a lounge coat and the bow tie with a necktie. If an invitation references creative black tie, don't let your mind run away with you; men can choose an unconventional color for their shirt or accessories.
Semiformal
At the lower end of the fancy scale is semiformal dress (considered informal in traditional parlance). Men need only wear a business suit, dress shirt, and tie; women can wear a flowy dress or cocktail dress or dressy separates.
Whatever the occasion or time of day, it's always best to respect the dress code requests of the host who sent the invitation. You wouldn't want to be caught at a formal dinner party in a purple cummerbund when everyone else is in hats and tails.
Recommentions:
off the shoulder dresses, wedding guest dresses