|George McDonald to Carl Spaatz, June 21, 1944
The Normandy landings and many other British and Allied operations were greatly facilitated by successful code-breaking efforts. For security reasons, information from decrypted German communications intercepts, which was given the code name ultra, was given only to a few high-ranking military leaders. This review of German Air Force (G.A.F) activity, made shortly after D-Day, contains such super-secret information. All persons to whom the review was sent were warned that they should burn their copies after reading them. Clearly not everyone obeyed the requirement.
Typed report. Carl A. Spaatz Papers, Manuscript Division, Library of Congress (219.5)
World War II