Mess dress uniformMess dress uniform is the most formal (or semi-formal, depending on the country) type of evening-wear uniform used by military personnel, police personnel, and other uniformed services members. It frequently consists of a mess jacket, trousers, white dress shirt and a black bow tie, along with orders and medals insignia. Design may depend on regiment or service branch, e.g. army, navy, air force, marines, etc. In modern Western dress codes, mess dress uniform is the supplementary alternative equivalent to the civilian black tie for evening wear.