: Letters or symbols painted on aircraft tails identified the group and its division. For instance, a "Square J" identified the 390th Bomb Group.

: A group was usually made up of four squadrons. For example, the 397th Bomb Group included the 596th, 597th, 598th, and 599th squadrons.

A was a primary tactical and administrative unit of the U.S. Army Air Forces (USAAF) during World War II, typically consisting of three to four flying squadrons and approximately 50 to 70 aircraft . These groups were organized into larger Wings and Air Divisions to execute strategic bombing campaigns across various theaters of war. Organizational Structure