"One simple word, BIGOT, is stamped in big letters across the Operation Neptune Initial Joint Plan of February 12, 1944, and from then until June 6, that stamp appeared on all supremely secret pieces of paper handled by D-Day planners. If any of those papers or maps had fallen into enemy hands, the invasion would have failed or been scuttled—a distinct possibility in the anxious days after Exercise Tiger.BIGOT was a code word within a code word, a security classification beyond Top Secret. When planners adopted Neptune as the code word for the naval and amphibious aspects of the invasion, they realized that greater protection had to be given to any document or map that even hinted at the time and place of D-Day. They chose the odd code word BIGOT by reversing the letters of two words—To Gib—that had been stamped on the papers of officers going to Gibraltar for the invasion of North Africa in November 1942.
Those who were to get date-and-place information were given special security back-ground checks. If they qualified, they were described as “Bigoted.” So when Eisenhower learned about the catastrophe off Slapton Sands, he wanted to know whether any of the dead or missing had been Bigoted. About ten men had. Those bodies were found and their documents collected. But had the Germans found any secrets on other bodies?
Allied code breakers, who eavesdropped on German communications, listened for days to determine whether the Germans had gained any new intelligence about D-Day. They had not. D-Day’s secrets were still safe.
The BIGOT maps and documents were created in isolated cocoons of secrecy. One was hidden in Selfridges department store in London. BIGOT workers entered and left Selfridges by a back door, many of them knowing only that they were delivering scraps of information that somehow contributed to the war effort. Others with BIGOT clearances worked on Allied staffs scattered around London and southern England. So restricted was the BIGOT project that when King George visited a command ship and asked what was beyond a curtained compartment, he was politely turned away because, as a sentinel officer later said, “Nobody told me he was a Bigot.”
The system occasionally broke down. In March 1944 a U.S. Army sergeant accidentally sent a package of BIGOT papers, some containing the target date and place of the invasion, to his sister. The family was of German descent, and the sister lived in a German section of Chicago. By chance the package broke open in a Chicago post office. Postal authorities saw BIGOT and Top Secret stamped on documents and called the FBI. Investigators cleared the soldier of espionage, though he was confined to his quarters until after D-Day. The FBI put everyone who had seen the papers under surveillance. Another serious breach came in May when a U.S. major general told guests at a London dinner party that D-Day would come before June 15. He was demoted and packed off to the United States, as was a Navy captain who had blabbed too much at another party."