The small, round skullcap of the ecclesiastic. The
official name is pileolus; other designations are: berettino, calotte, subbiretum (because worn under the biretta), submitrale (because worn under the mitre), soli-deo. The pope's zucchetto is white, that of the cardinals red, even when the cardinal is a member of an order. Cardinals who had been secular priests received the red zucchetto and ...