service uniform would be replaced by Army Green service uniforms. The U.S. Army intends to maintain the dress blue uniforms for ceremonial use. The U.S. Army's uniform regulations also define a class of "special ceremonial units," that are authorized to wear distinct ceremonial regimental uniforms for ceremonies and public duties. They include select U.S. Army band and guard units, including the 3rd Infantry Regiment's Commander-in-Chief's Guard, the First Troop Philadelphia City Cavalry, and some National Guard. Additionally, cadets at the United States Military Academy wear a cadet grey swallow-tailed blouse with white trousers and black shako for parades and drills. U.S. Marine Corps The most formal of a Marine's uniforms outside of the elaborate evening dress uniforms of officers and senior enlisted, it is often referred to as "Dress Blues", due to its color (as distinguished from the green and khaki service uniforms), and can be worn in many forms. It is the only uniform of the United States military to use all of the colors of the nation's flag and incorporates button designs which are the oldest military insignia still in use in the United States Armed Forces to this day. The various designations used in Dress Blue include: Dress Blue "A" has a long sleeve choker-collar midnight blue outer blouse, white barracks cover, with all medals and service ribbons. Enlisted coats have a red trim and more buttons down the middle of the coat than officers. Dress Blue "B" is the same as "A", but service ribbons and marksmanship badges are worn instead of medals. Dress Blue "A" (with medals worn) is strictly reserved for official ceremonies, while Dress Blue "B" may be worn on leave or liberty. Dress Blue "C" is the dress blue uniform worn with the long sleeve khaki shirt (without coat). Service ribbons and badges may be worn. Dress Blue "D" is the dress blue uniform worn with the short sleeve khaki shirt (without coat). Service ribbons and badges may be worn All the blue uniforms have the same trousers, cover, and black shoes, with the exception of general officers who wear dark blue trousers in the same color as the coat. Officers, Staff Noncommissioned Officers, and Noncommissioned Officers wear blood stripes on their trousers. Blood stripes are 1.25" in width for NCOs and SNCOs, 1.5" for officers, and 2" for general officers. A sword may be worn when the individual is in command