Black tie

Unlike white tie, which is very strictly regulated, black-tie ensembles can display more variation. In brief, the traditional components are:

• A jacket with ribbed silk facings (usually grosgrain) on a shawl collar or peaked lapel (while a notched lapel is a popular modern choice, it is not traditionally considered correct)
• Trousers with a single silk or satin braid covering the outer seams
• A low-cut waistcoat or cummerbund
• A white dress shirt with a turn-down or wing collar collar, shirt studs (optional), and cufflinks (a marcella front is traditional, but other styles are also accepted. A black ribbed silk bow tie matching the lapel facings (self-tie bow ties are preferred but not necessary)
• Black dress socks, usually silk or fine wool
• Black shoes, highly polished or patent leather Oxfords, or patent leather court shoes

from http://en.wikipedia.org/wiki/Black_tie