A stiff square cap with three or four ridges across the crown. Birettas are worn especially by Roman Catholic clergy and are black for priests,purple for bishops,and red for cardinals.

• 法冠帽顶有三或四道边的硬方帽，尤为罗马天主教教士所戴，牧师戴黑色，主教戴紫色，红衣主教戴红色