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 on North Africa: that the Tunis Air Corps probably abandons Matmata airfield, on March 22; and of reconnaissance tasking for the Tunis Air Corps, on March 22; on Yugoslavia: on the status of Operation WEISS on March 21, with a combined German/Croatian attack being supported by German Air Force (GAF) bombers against enemy forces in the Virovitica area; and that GAF units are to deploy to Agram; a German Navy summary report for March 21 on operations in the Black and Mediterranean Seas; and on the Russian Front: a situation report for March 21; and of GAF reconnaissance results for March 20.