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 to the Assistant Chief of Air Staff Intelligence (ACASI) for the Chief of the Air Staff (CAS) from C; it includes a query from the Prime Minister (PM) and a comment by the CAS on the German Air Force (GAF) report on all fronts for January 15-16, including reports of RAF raids on Emden and Hamburg, and German raids on targets in the U.K.