I've just acquired a postcard of my grandfather as a handsome young L/Cpl in the Durham Light Infantry around (I would guess) 1914-1915. In addition to the stripe on each sleeve (which has an interesting checked texture) he is wearing collar dogs. They appear to be crossed picks and rifles, with the sling of the rifle hanging down to round out the X shape. I assume this designated labour or works units? Would be interested in any further information anyone has on this.