German number system in the early years of Starfighter operation
The tactical number system was based on the idea to identify the aircraft of the corresponding
wing/squadron. This identification system was used until 1967.
It consisted of 2 letter and 3 numbers, with the Iron Cross (Eiserne Kreuz) in between.
  The 1st letter indicated the tactical role
  Luftwaffe B: Waffenschule (OCU)
    D: Jagdbomber (Fighter Bomber)
    E: Aufklärungsflugzeug (Recce Aircraft)
    J: Jagdflugzeug (Fighter)
    K: Werkstattflugzeug (Factory Aircraft)
    N: Sonderflugzeug (Special Task Aircraft)
  Marine T: Trainingsflugzeug (Trainer)
    V: Jagdbomber (Fighter Bomber)
  General Y: Erprobungsflugzeug (Test Aircraft)
  The 2nd letter indicated the Flying Wing
  Category B B: WaSLw 10 BB
    F: TSLw 1 BF
    G: Luke (planned, but never used) (BG) *(see note 1)
  Category D A: JaboG 31 DA
    B: JaboG 32 DB
    C: JaboG 33 DC
    D: JaboG 34 DD
    F: JaboG 36 DF
    R: LPR 1 (Modifications) DR
  Category E A: AG 51 EA
    B: AG 52 EB
  Category J A: JG 71 JA
    D: JG 74 JD
  Category K C: FIAT KC *(see note 2)
    E: Messerschmitt KE
    F: Lockheed KF *(see note 3)
    G: Fokker KG
  Category T A: MFG 1 TA
    B: MFG 2 TB
  Category V A: MFG 1 VA
    B: MFG 2 VB
  Category Y A: ErpSt 61 YA
  1st and 2nd letter together resulted in the wing code
  The meaning of the 1st number was different in the Luftwaffe and Marine
  Luftwaffe number: 1 1st squadron
    number: 2 2nd squadron
    number: 3 TF-104G / F-104F
    number: 1 MFG 1
    number: 2 MFG 2
  The meaning of the 2nd and 3rd number was different again in the Luftwaffe and Marine
  Luftwaffe number: 01-30 1st squadron
    number: 31-60 2nd squadron
    number: 61-80 TF-104G / F-104F
  Marine number: 01-55 MFG 1
    number: 01-53 MFG 2
  This system was not used by the WaSLw 10 !
  Some examples:
  BB+375 WaSLw 10 F-104F
  BF+011 TSLw 1 F-104F
  BG+129 Luke F-104G (planned, but never used)
  DA+122 1.Sqn JaboG 31 F-104G
  DF+241 2.Sqn JaboG 36 F-104G
  DR+233 LPR 1 F/TF-104G (for modification)
  EB+371 AG 52 TF-104G
  JD+101 1.Sqn JG 74 F-104G
  TA+160 MFG 1 TF-104G
  VA+101 MFG 1 F-104G
  VB+201 MFG 2 F-104G
  YA+104 ErpSt 61 F-104G
  ND+110 Display aircraft for exhibition "Unsere Luftwaffe"
  DA+031 MTT for functional test flight of TF-104G after reassembling before delivery
In 1967/68 the system was changed to the new German serial numbers (tactical).
The change was ordered on November 13, 1967, and was effective January 1, 1968.

The change of the coding on the aircraft was done in 1968 over a timeframe of several month!

Four numbers starting at 20+01 to 29+21 were assigned to the individual aircraft and not to the unit anymore.
Between number 2 and 3 is the well known Iron Cross (Eiserne Kreuz). This system is still in use as of today.
Example: F-104G construction number 2043 became serial number 2036 coded as 20+36.

The number "2" indicates a F-104, and the individual aircraft was registered in numerical sequence.
20+01 to 26+90: F/RF-104G
27+01 to 28+35: TF-104G
29+01 to 29+21: F-104F

F-104 already out of service at that time did not get a serial number
Example: F-104G construction number 2077, crashed coded as DC+119 1967.
All German F-104 in service in the USA at that date got a "shadow" German serial number
Example: F-104G construction number 2035, US serial number 63-13251 got a "shadow" serial number 2028,
but it was never used or seen on the aircraft! The aircraft was coded as 13251.
All German F-104 already out of service in the USA at that date did not get a serial number
Example:F-104G construction number 2032, US serial number 63-13248, crashed 1965 coded as 13248.

*note 1: BG codes:
The codes BG+101 until BG+148 were used by the MatAmt (German Logistic Command) for the transfer from Germany to the Lockheed factory at Palmdale, USA for re-assembly. The plan was to code the German F-104 operating at Luke with "BG" codes, but this was not legal according to USAF regulations. That means that the "BG" code was used ONLY on paper and was never seen on an aircraft.

*note 2: KC codes:
The codes KC+101 until KC+116 were reserved for the Fiat G-91 T.3's with construction numbers 91-2-0001 until 91-2-9916. Only the first G-91 was coded that way during the test flights at Turin-Caselle. That is why the F-104G were coded starting with KC+117.

*note 3: Lockheed codes:
Initially the Lockheed production code was DA (not to be mixed up with the JaboG 31 code). Construction numbers 2001 to 2024 were coded DA+101 to DA+121. Construction numbers 2025 to 2097 were coded KF+101 to KF+172.

compiled by: Hubert Peitzmeier
update: @ January 14, 2021