text: Appendix E
  Table E-3. Assignment of first letter (example)
  Senior Army Headquarters Letter
  USARCENT C
  USAREUR-AF E
  USASOC F
  ARNORTH N
  USARPAC P
  ARSOUTH S
  ARNORTH – U.S. Army North, ARSOUTH – U. S. Army South, USARCENT – U.S. Army Central,
  USAREUR-AF – U.S. Army Europe and Africa, USARPAC – U.S. Army Pacific,
  USASOC – U.S. Army Special Operations Command
  E-22. The second letter in the unit identification of the AIRSUPREQ number indicates the upper echelon
  tactical HQ. If an Army corps is operating in a tactical role, this letter should identify the Army corps where
  the request originated. If the corps is not operating as a tactical HQ, then an Army division should be the
  upper echelon tactical HQ. Table E-4 is a notional example of letter assignment for upper echelon tactical
  HQ.
  Table E-4. Assignment of second letter (example)
  Upper Echelon Tactical Headquarters Letter
  I Corps A
  III Corps B
  V Corps C
  XVIII Airborne Corps D
  E-23. The third letter in the unit identification of the AIRSUPREQ number indicates the lower echelon
  tactical HQ. When operating beneath a tactical corps HQ, the third letter should identify the tactical division
  HQ where the request originated. In the absence of a tactical corps HQ, the third letter should identify the
  brigade within the division that submitted the AIRSUPREQ. When Army divisions operating as upper
  echelon tactical HQ submit AIRSUPREQs in support of a maneuver brigade’s operations, the third letter may
  be used to identify the brigade being supported. Table E-5 is a notional example of letter assignment for
  lower echelon tactical HQ.
  Table E-5. Assignment of the third letter (example)
  Lower Echelon Tactical Headquarters Letter
  3rd Infantry Division A
  10th Mountain Division B
  82nd Airborne Division C
  101st Airborne Division D
  7th Infantry Division E
  25th Infantry Division F
  11th Airborne Division G
  1st Infantry Division H
  1st Cavalry Division I
  1st Armored Division J
  4th Infantry Division K
  3rd Armored Cavalry Regiment L
  E-24. The last three characters in the AIRSUPREQ number are used as sequence numbers, identifying the
  number of the request submitted by the unit. The numbers do not represent the type of air mission. Using the
  data in Tables E-2 through E-5, an AIRSUPREQ submitted by 82nd Airborne Division for March 1st, 2023,
  with XVIII Airborne Corps as their HHQ, operating in the CENTCOM AOR, would have the following
  AIRSUPREQ number assigned:
  * CACDC001.