Ratio 2:5 Type B Used on some night flying aircraft, especially heavy bombers, 1918–1919. (Known at this time as the "night roundel"). On all surfaces of NIVO-colored night bombers from 1923 until NIVO phased out; Used on camouflaged aircraft in all positions from Summer 1938 until superseded by Type A-1 roundels. Used on upper surfaces of many aircraft until 1947. On fuselage sides and upper wings of overall PRU Blue photo-reconnaissance aircraft 1940–1944 (e.g.:Photo-reconnaissance Spitfires) and aircraft with "High altitude" camouflage (e.g.: de Havilland Hornet) 1944–1947