Etymologically, the word biretta is Italian in origin and would more correctly be written beretta. It probably comes from birrus, a rough cloak with a hood, from the Greek pyrros, flame-coloured, and the birretum may originally have meant the hood.Even at the present day birettas vary considerably in shape. Those worn by the French, German, and Spanish clergy as a rule have four peaks instead of three; while Roman custom prescribes that a cardinal’s biretta should have no tassel. As regards usage in wearing the biretta, the reader must be referred for details to some of the works mentioned in the bibliography. It may be said in general that the biretta is worn in processions and when seated, as also when the priest is performing any act of jurisdiction, e.g. reconciling a convert. It was formerly the rule that a priest should always wear it in giving absolution in confession, and it is probable that the ancient usage which requires an English judge assume the “black cap” in pronouncing sentence of death is of identical origin.