The British government started war rationing in January 1940 with the issuing of food coupons. This was designed to ensure a fair distribution as imported food was in short supply. Due to the attacks of燝erman U-Boats on merchant ships in the Atlantic, it was almost impossible to import cloths and other fabrics. Civilian clothes rationing was introduced in June 1941 with each man, woman and child being issued with a clothing ration book consisting of coupons to be detached by the shopkeeper when they became valid. Because of the scarcities it was a case of 'Make do and Mend' for housewives in particular, becoming an important part of the war effort. Restrictions on rationed goods were gradually lifted three years after war had ended. Rationing on clothes ended on 15 March 1949. Scarcity resulted in the "Black Market" created with trade in goods that violated the rationing regulations.