Young Blonde Girl Changing Her Evening Dress At Home

Black tie
Briefly, men wear a dinner jacket (US English: tuxedo coat); trousers, uncuffed, with one stripe on leg seams; shirt (stiff wing or soft folded collar) with either a placketed, pleated, piqué, or ruffled front; a black bow tie; a black evening waistcoat or a cummerbund; black, patent leather or calf Oxfords or court shoes; cuff links and shirt studs; accessories. However, this is not strictly formal. It would correctly be classified as semi-formal.
Again, a variety of dresses is worn by women, including cocktail dresses, little black dresses, and evening gowns.