The German language term Stab (literal translation: "staff") was used during World War II to designate a headquarters unit of the German Luftwaffe (air force). There were Stab units at the level of a Gruppe or Geschwader – units that were equivalent to wings and groups in the air forces of the English speaking world. Stab units directly controlled aircraft as well as controlling those belonging to subordinate units.
These command units used the mandated green "staff aircraft" colour for the third character (the individual aircraft's letter) of their alphanumeric Geschwaderkennung wing code, to distinguish their aircraft from the rest of air units in the same unit. These units were divided in the following form, for the fourth and last character normally used to distinguish individual Staffeln (squadrons) from the letter "H" onwards in Luftwaffe wing codes:
On some occasions they also used letters G, Q, I, J, W and others, or numbers, but these were used less commonly. These units used the red-blue or blue-white-blue Reich Defense (German Reich metropolitan defense) sign. Under the cockpit, the rank of the air commander might have been indicated via a rank sign, with or without additional letters as mentioned above.
For example: