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 reports: a report on a query by the Air Officer Commanding (AOC) in Chief South on a failure to reinforce forward air bases on March 4; a German Air Force (GAF) report of SIGINT on enemy ground dispositions, from March 3; a fragment of a German report from March 3; a GAF report of raids on Egypt on the night of March 2-3; part of a German report on enemy activities on the Russian front including the arrival of British specialist instructors on March 3; and a German 51st Army Corps report from March 1.