Worn by the pope, the pallium symbolizes the "plenitudo pontificalis officii" (i.e., the "plenitude of pontifical office"); worn by archbishops, it typifies their participation in the supreme pastoral power of the pope, who concedes it to them for their proper church provinces. Similarly, after his resignation, he may not use the pallium; should he be transferred to another archdiocese, he must again petition the pope for a new pallium. The new pallia are solemnly blessed after the First Vespers on the feast of Saints Peter and Paul, and are then kept in a special silver-gilt casket near the "Confessio Petri" (tomb of St. Peter) until required. The pallium was formerly conferred in Rome by a cardinal deacon, and outside of Rome by a bishop; in both cases the ceremony took place after the celebration of Mass and the administration of an oath. Since the Second Vatican Council (1962–65), the liturgy for the conferral of the pallium as it appears in the liturgical books is to take place at the beginning of the Mass in which the archbishop takes possession of his see; however, the practice of Pope John Paul II and Pope Benedict XVI has actually been to summon all new metropolitans to Rome to receive the pallium directly from the hands of the pope on the Feast of Saints Peter and Paul.