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 South and South-east Europe: of preparations for gas warfare, under the covername HIRSCHHORNSALZ, to be known as CLINKER, on April 5; on West Europe: of 29 German Air Force (GAF) aircraft being destroyed in an Allied raid on Lyon-Bron airfield on April 30; on South Europe: of air attacks on railway bridges in the Gulf of Genoa area, on May 3; that GAF units in upper Italy are to be prepared for action in the event of an emergency in the west, with commanding officers to visit the new operations area, from May 2; on an emergency in the west, concerning the arrangements for the diversion of transferring aircraft units to other airfields in the event that enemy air attacks prevent use of the intended airfield, on May 2; Naval Headlines, covering that the German Navy is to take measures to combat sabotage; from the Japanese military attaché in Turkey, giving the views of the Turkish Chief of General Staff on the progress of the war, saying a second front is unlikely and the Germans will hold the Soviet forces, on April 12; from the Japanese ambassador in Berlin, describing Allied air raids, that German morale is high and that there has been no decisive effect on the essential war industries, on April 28; and from the Japanese representative of the Ministry of the Interior in Berlin, detailing the percentage of air raid damage to German cities, on April 18.