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 includes the following correspondence: from C to the Assistant Chief of Air Staff Intelligence (ACASI) for the Chief of the Air Staff (CAS), including intelligence on North Africa, with a German Air Force (GAF) reconnaissance report of January 22 with the Prime Minister's (PM's) query and CAS's reply.