Blouses (and many women's shirts with buttons) usually have buttons reversed from that of men's shirts (except in the case of male military fatigues). That is, the buttons are normally on the wearer's left-hand and the buttonholes are on the right. The reasons for this are unclear, and several theories exist without have conclusive evidence. Some suggest this custom was introduced by launderers so they could distinguish between women's and men's shirts. One theory purports that the tradition arose in the Middle Ages when one manner of manifesting wealth was by the number of buttons one wore. Another that the original design was based on armour which was designed so that a right-handed opponent would not catch their weapon in the seam and tear through, and that a person could draw a weapon with their right-hand without catching it in a loose seam of their own clothes.