Like many things that we continue as customs in the Church, this skullcap was originally developed for a practical purpose. It was worn to cover the tonsure (shaved top of the head) of the cleric, protecting him from the elements.

One source says there is no connection with the Jewish head covering that men wear (yarmulke) but others would say that it has its source in this Jewish custom, as do many of our practices.

The use of different colours and materials developed in the Middle Ages. In 1464, the pope granted cardinals the red zucchetto. This led to adaptation of the zucchetto by others in the hierarchy in black.

The popes themselves began to wear the zucchetto only in the 1500s, using instead the camauro which is more of a bonnet (can be seen in pictures of Pope John XXIII). The papal motu proprio of 1968 reinforced the use of the zucchetto for the hierarchy.

During and after the Renaissance, a variety of colours and materials became prevalent with the colours designating rank. Only the pope can wear white, except for religious orders whose habits are white. On June 17, 1867, Pius IX granted amaranth red skullcaps to patriarchs, archbishops and bishops. Other clergy can only wear black.

Not restricted to the hierarchy, as mistakenly believed the last 30 years, it is the option of all clerics with its colour white, red, violet or black denoting the rank of the wearer.

There are all sorts of rules for wearing the zucchetto. It must always be worn under the mitre. It must be removed during the Mass from the Sanctus to just after Communion, as well as when bowing to the altar. It is always removed before the exposed Blessed Sacrament and in processions of the Blessed Sacrament.

Some prelates remove it during the Lord's Prayer or the Gospel but neither of these are required. Any cleric who is not a bishop or cardinal should remove his skullcap in the sacristy before entering the sanctuary.

Everyone must remove the zucchetto when the pope enters a room and normally keep it off while he is present. However, as the present pope has long meetings, it is permissible to replace it after all the formal greetings are completed, following the lead of the senior cleric present. There are other rules for the zucchetto when the pope is present for a liturgical celebration.

When you have a private audience, you may present a white silk zucchetto to the pope who will put it on his head and give you the one he is wearing as a sign of his appreciation. Although Pope John Paul doesn't encourage this practice, he honours the 400-year-old custom but not in large gatherings.