During World War II, the suffix Stab (Staff) was used in the German Luftwaffe (air force) to designate a headquarters unit. This applied to subordinate units in each Gruppe or Geschwader — the equivalent units to wings and groups in other air forces. These command units used the green colour of their aircraft and individual identification letters to distinguish their aircraft from the rest of air units in same sections. These units were divided in the following form: For example: