In the mid-20th century, the Post Office Department provided codebooks to its postal inspectors. They were expected to use codes while sending sensitive information by telegraph. The Cipher Code handbook from 1941 contained instructions for using the ciphers while sending messages. The 1959 Telegraph Code book,also issued by the Post Office Department, expanded from the previous edition’s 2 page booklet to 12, with detailed instructions and code words to use while sending secure telegraph messages. The later book included a number of changes to the code phrases, such as: “Fapar” was to be used in place of “Bilay” for train wreck, “Fapet” instead of “Bible” for airmail wreck, and “Karby” replaced the phrase “Dados” for “meet and protect Federal Reserve shipment on next train arrival.”
The U.S. Postal Inspection Service