A coloured yarn of jute laid up in a strand of rope to identify the materials from which it was made. Commercially made manila rope was marked with a black rogue's yarn, naval manila rope with red in each of two strands. Commercial sisal rope had a red rogue's yarn, naval sisal had yellow in each of two strands. Commercial hemp had no rogue's yarn, naval hemp had red in all three strands. Coir rope was marked with a yellow rogue's yarn in one strand only. Originally, rogue's yarns were used only in naval rope and indicated from their colour the ropeyard in which they were made. They were introduced to stop thieving by making the rope easily recognizable, as in the days of sailing navies naval rope was considered far superior to any other, and there was a great temptation to smuggle it out of the dockyards and sell it to owners or captains of merchant vessels.