Cryptonym: ZACABIN
https://www.archives.gov/files/iwg/declassified-records/rg-263-cia-records/second-release-lexicon.pdf
CIA document: Research Aid: Cryptonyms and Terms in Declassified CIA Files Nazi War Crimes and Japanese Imperial Government Records Disclosure Acts: Page 63: ..."Term: ZACABIN. Definition: CIA Office of Special Operations (OSO)..."
https://www.cia.gov/readingroom/docs/PASTIME%20%20%20VOL.%201_0004.pdf
Undated CIA document: Titled: Questions on Stay-behind nets, BOB (Berlin Operating Base): ..."1. The principal need at the present time is a more specific statement on the purpose of our stay-behind mission. In addition to a general definition of what is meant by stay-behind and for what purposes and eventualities the program in Germany is designed, we must also have a comprehensive study indicating which targets we shall be expected to cover. We should go to future customer agencies for this information. If our stay-behind program is primarily designed to furnish OB information, then we must perforce go to the military for an outline of targets. This is the only action we can take which will give us assurance that our energies are not being dissipated on secondary areas. While in all probability we ourselves could make up a fairly common-sense list, the war plans for the defense of Europe, the strategic bombing projected for rear areas, and perhaps plans for future liberation must of necessity be taken into account in drawing up such a list...12. I believe that perhaps closer stay-behind cooperation and coordination in Washington between ZACADDY and ZACABIN would result in more direct support in the field. ZACADDY support to date has been excellent, but our contact has always been loose and informal; 'undefined' would perhaps be a better word...26. It might be wise to set up a continuing liaison with present ZACABIN/ZACACTUS stations which have been dropping W/T operators and agents into Eastern Europe. If they can tell us on the basis of their experience what they would like to find in the way of reception facilities for their agents, we would have a sound idea of the program we must set up now for dropping agents into Germany later..."
https://www.cia.gov/readingroom/docs/BOLSCHWING%2C%20OTTO%20%28VON%29%20%20%20VOL.%202_0001.pdf
01/04/52: Dispatch from COS, Karlsruhe to Chief, Foreign Division, M: Subject: General - Operational. Specific - USAGE: ..."2. To begin, our comments on the various paragraphs in MGKW-11190 follow: a. Par. 1 - 'GRUESOME (Detachment 35 of G-2 US Forces Austria - Det 35 G-2 USFA) is the proper agency to handle (USAGE), but dependent on transfer of GRUESOME to ZACABIN.' When will this occur? We feel that if such transfer is not effected in the near future, it will only result in further vacillation and indecision on the ultimate disposition of USAGE. Further, we are inclined to agree to a great extent with the objections by the Austrian station to GRUESOME handling of USAGE as expressed in par. 3, MASA-1030, and to these add our own comments that no one presently on the GRUESOME staff except Clarence Foley is now authorized to read the extensive ZACABIN files on USAGE operations. Rewriting of these could not be staffed by POB, nor, probably, by the Austrian station..."
104-10224-10002: MURPHY, DAVID E., OP
11/01/52: Dispatch from COS, Karlsruhe to Chief, Foreign Division N: Subject: Administrative Promotion of (REDACTION) - NOTLOX (?): "1. Recommendation is made hereby for the promotion of Subject from grade GS-13 to grade GS-14. Subject was assigned to (unintelligible) as Chief of the Soviet Operations Section in February 1951 charged with the overall direction of the (unintelligible) operational effort into the (unintelligible). In Sept. Subject took over as Chief of the Combined Soviet Operations Base in (unintelligible) responsible for the joint ZACABIN-ZACACTUS (CIA Office of Policy Coordination - OPC) effort. Into this ever increasing area of operational and acquisitive (?) responsibility Subject has brought a high prior motivation, outstanding drive, and excellent operational knowledge...2. As Chief, (unintelligible), Subject is in direct command over approximately 80 ZACABIN and ZACACTUS personnel including a very large training installation at (unintelligible) 60 miles away from (unintelligible) Headquarters..." Handwritten note at bottom of page: "A very well earned promotion. MLC."