Farewell Dossier
The Farewell Dossier was the collection of documents that Colonel Vladimir Vetrov, a KGB defector "en place" (code-named "Farewell"), gathered and gave to the Direction de la surveillance du territoire (DST) in 1981–82, during the Cold War. Vetrov was an engineer who had been assigned to evaluate information on NATO hardware and software gathered by the "Line X" technical intelligence operation for Directorate T, the Soviet Union directorate for scientific and technical intelligence collection from the West.