Op-20-G

The various designations for departments in Op-20-G can be a confusing tangle of acronyms which changed from month to month. I’ve been able to sort out the departments, at least as they were organized 14 April 1944 thanks to Walter Reiss, husband of former WAVE Bertha Boron, who received this information from the National Archives and shared it with me. If you are also confused by this classification system yet want to clarify it for yourself, I recommend the Glossary of US Naval Abbreviations published online by the Naval Historical Center

Op-20-G’s Subdivision Order No. 69

14 April 1944

The cognizance and functions of the various departments and sections under Op-20-G, and the relationship between certain departments and sections, are as follows:

  • I – Assistant Director and Assistants
  • 20-G: Assistant Director of Naval Communications for Communications Intelligence
  • 20-G-1: Operation and Planning (Technical)
  • 20-G-10: General Assistant to 20-G-1
  • 20-G-20: General Assistant to Op-20-G for dediCated-administration
  • II-Operations Coordination and Planning Staff
  • GX (D/F and Intercept Facilities
  • The Staff includes the following members:
  • Officer in Charge, Fleet Radio Unit, Melbourne
  • Officer in Charge, Fleet Radio Unit, Pacific Area
  • G-30 – Pacific Theater
  • G-40 – Atlantic Theater
  • G-50 – Research
  • G-60 – Technical Services
  • G-70 – Clandestine
  • G-80 – Strategic Information Coordinator
  • GC – Communications
  • GD-A – Intercept Control
  • GD-P – Intercept Control
  • GH – Secretary of Staff
  • GI-A – Correlation and Dissemination (Atlantic)
  • GI-D – Correlation and Dissemination (Diplomatic)
  • GI-P – Correlation and Dissemination (Pacific)
  • GR – Personnel
  • GT-A – Traffic Analysis
  • GT-P – Traffic Analysis
  • GX – (See end of list).
  • GY-A – Cryptanalysis
  • GY-P – Cryptanalysis

14 April 1944

OP-20-G’s SUBDIVISION ORDER NO. 69:

Subj: Cognizance and Function of Sections Under Op-20-G.

Ref: (a) U.S. Naval Communication Intelligence Organization.

  • 1. This Subdivision Order supersedes Op-20-G Subdivision Order No. 67, dated 14 February 1944.
  • 2. The cognizance and functions of the various departments and sections under Op-20-G, and the relationship between certain departments and sections, are as follows:
  • I – Assistant Director and Assistants.

    • 20-G: Assistant Director of Naval Communications for Communication Intelligence.
    • 20-G-1: Operation and Planning (Technical)
    • 20-G-10: General Assistant to 20-G-1.
    • 20-G-20: General Assistant to Op-20-G for dediCated-administratiion
  • II-Operations Coordination and Planning Staff.

    The Staff is composed of officers stationed at Washington, who are fitted by experience and training to assist in the planning of future operations of the Communication Intelligence organization. The assistants to the Assistant Director as well as the officers in charge of the Fleet Radio Units at Pearl Harbor and Melbourne are ex-officio members. The Planning Staff, as a whole, will function principally as a coordination group with advisory powers. Small committees will be designated to plan specific new projects.

    GX (D/F and Intercept Facilities) has solely staff duties in connection with the coordination of Communication Intelligence activities, and these will be listed herein.

  • GZ-A – Translation
  • GZ-P – Translation.
  • GX – D/F and Intercept Facilities.
  • III – The Washington unit.

    • A. dediCated-administrative Department

      • G-20 – Head of dediCated-administrative Department
      • GB – Secretariat
      • GQ – Supply
      • GR – Personnel Records, Training and Allocation
      • G-21 – Senior Wave Assistant
      • G-22 – First Lieutentant (also Fire Warden and Air Raid Warden
      • G-23 – Security Officer
      • G-24 – Assistant Security Officer and Assistant Fire and Air Raid Warden
      • G-25 – Morale
      • G-26 – Transportation
      • G-27 – Navy Department Liaison
    • B. Pacific Theater Department

      • G-30 – Head of Pacific Theater Department
      • GD-P – Intercept Control (Pacific)
      • GT-P – Traffic Analysis, D/F and RFP (Pacific)
      • GY-P – Cryptanalysis and Decryption (Pacific)
      • GZ-P – Translation and Code Recovery (Pacific)
      • GI-P – Correlation and Dissemination (Pacific)
    • C. Atlantic Theater Department

      • G-40 – Head of Atlantic Theater Department
      • GD-A – Intercept Control (Atlantic)
      • GT-A – Traffic Analysis D/F and RFP (Atlantic)
      • GY-A – Cryptanalysis and Decryption (Atlantic)
      • GZ-A – Translation (Atlantic)
      • GI-A – Correlation and Dissemination (Atlantic)
    • D. Research Department

      • G-50 – Head of Research Department
      • GE – Cryptanalytic Research
      • GJ – Radio Engineering and Research
      • GK – Mathematical and Physical Research
      • [ed. note: written in by hand:] GP – Statistical Personnel Pool
      • GM – Machine Research
      • GV – Foreign Language Research
    • E. Technical Services Department

      • G-60 – Head of Technical Services Department
      • GB – Secretariat (Technical)
      • GC – Rapid Communications
      • GL – Collateral Information
      • GS – Machine Processing
      • GW – Traffic Center
    • F. Clandestine Department

      • G-70 – Head of Clandestine Department
      • GU – Clandestine
    • G. Diplomatic Department

      • G-80 – Strategic Information Coordinator