Field officer rank category (OF-3 to OF-5) of the Russian Imperial Army and Navy until 1917. The British Army (in which these officers are called officers of field rank), and some others in the Commonwealth (including the Australian Army and New Zealand Army), also include the brigadier in this category: the equivalent in other armies is a general officer (the brigadier general). Today, a field officer in the United States (here called field grade) Army, Marine Corps, and Air Force is typically a major, lieutenant colonel, or a colonel: Field officer A field officer, field-grade officer, or senior officer is an army,
Field officer Field officer A field officer, field-grade officer, or senior officer is an army, Marine, or air force commissioned officer senior in rank to a company officer but junior to a general officer. In most armies this corresponds to the ranks of major, lieutenant colonel and colonel, or their equivalents. Some countries also include brigadier in the definition. Historically, a regiment or battalion's field officers made up its command element. In the Canadian Armed Forces, the equivalent of field officers are senior officers (); they include the army and air force ranks of Major, Lieutenant-Colonel, and Colonel, and the naval ranks