One problem often developed, the gap between the blouse and trousers would open up in extreme movement and buttons popped, so braces were issued; in some cases a sweater was worn. A woollen shirt was typically worn under the wool blouse. Wearing an open collar blouse (with tie) was initially restricted to officers, other ranks buttoning the top button of the blouse and closing the collar with a double hook-and-eye arrangement. Short webbing anklets covered the gap between the trousers and the ankle boots, further adding to the streamlined look and keeping dirt out of the boots without having to use a taller, more expensive leather boot.