Officers during the Civil War from the state forces were known by the rank suffix "of volunteers"; if Regular Army, these officers were known by the rank suffix "USA". Thus, a state regiment colonel would be known as "colonel of volunteers" while a Regular Army captain would be known as "Captain, USA". Regular Army officers of the Civil War could accept commissions in volunteer forces and could also be granted brevet ranks (higher ranks than the permanent commission). In some cases, officers held as many as four ranks: a permanent rank (called "full rank") in the Regular Army, a full rank in the volunteers, and brevet ranks in both as a result of battlefield promotion, meritorious service or Congressional action. The officers typically would only refer to themselves by the highest rank they held. An example is Union Army officer James Henry Carleton who was a "full" captain, a brevet major in the regular army, a colonel of volunteers, and a brevet brigadier general.