The Operational Groups Field Manual was a top secret document written in 1944 by the Office of Strategic Services (OSS), the precursor of the Central Intelligence Agency (CIA). The purpose of the manual was to provide information, guidance, and basic doctrines for forming, training, and deploying operational groups during World War II. The manual was eventually declassified and is now a document of historical interest giving insights into spycraft and special operations during World War II.
Office of Strategic Services (OSS) was the intelligence agency of the United States during World War II. It is the precursor to the Central Intelligence Agency (CIA).