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-east Europe: a report by the German naval authority on Kos as to shipping in the area, on October 17; on the possibility that if the German operation based on Kos does not take place during the night of October 17, then German ships are to be permitted to withdraw temporarily into the Cyclades area, on October 17; and that men of unpatriotic and criminal tendencies and who are unsuitable as soldiers are to be weeded out of the Germans' 999 battalions, on October 4.