Under the British Civilian Clothing Order CC41 that went into effect in 1941, severe rationing of cloth and other embellishments were necessary during World War II. The United States passed similar enforcements. The British laws that were introduced made it illegal for a manufacturer or designer to use unnecessary buttons, stitches, pockets, pleats, or any embellishment that was not functional to the garment. The Incorporated Society of London Fashion Designers was called upon to design clothes to help enforce the law and to boost morale during the war years. The government issued women a limited number of coupons with which they could buy clothes.
Historical Dictionary of the Fashion Industry. Francesca Sterlacci and Joanne Arbuckle.