A file of signals intelligence reports, messages, and correspondence issued by the Government Code and Cypher School and sent by the head ('C') of the Secret Intelligence Service (MI6) to the Prime Minister, Winston Churchill. This file contains a message from C to the Assistant Chief of Air Staff Intelligence (ACASI), concerning a query from the Prime Minister (PM) for the Chief of the Air Staff (CAS): on a German Air Force (GAF) general report for July 24; with a minute from the PM; and CAS's reply on the coversheet.