Cryptonym: CALL
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 18: ..."Term: CALL. Definition: Cable indicator for West German foreign intelligence..."
04/18/63: Cable from Hamburg to Director (Info: BRUS, FRAN): Slugline RYBAT TYPIC AMLEG CALL: "1. AMLEGS-1 (Manuel Leveque Cajaraville), 2, 3, 4 (Alberto Gutierrez Barbero), 5, 6, 7, 8, 11, 24, 25, and 28 probably willing and able perform sabotage on ships if requested. Unless operation considered of vital importance overriding other potential these agents, prefer not to employ them this function. Above represents partial assets Bahia de Mariel, Oriente, Sierra Maestre, and Las Villas. Early May, including Sierra Maestre and Camilo Cienfuegos, approximately five Cuban ships will be on high seas..."
104-10170-10168: DISPATCH: RICHARD CASE NAGELL PUBLICATION
03/31/70: Dispatch from Chief of Base, Berlin to Chief, European Division (COS, Germany): Subject: CALL/MHORDER/Operational Richard Case Nagell Publication: "1. Forwarded herewith for Headquarters is a document recently received from the Chief of the Aliens Police of Department II of the West Berlin police concerning the Richard Case Nagell affair. The document was received by the Aliens Police via the mails in a letter addressed directly to the Aliens Police in West Berlin. The envelope was destroyed by the clerk who opened it and there is therefore no way of knowing whether it was mailed in the United States or elsewhere or who the sender was. It has evidently been published by Nagell himself. 2. The attachment may be of interest to LNERGO (FBI). (Signature for) Winfield A. Calvin."