 The 1969 revision by Pope Paul VI divided feast days into "solemnities", "feasts" and "memorials", corresponding approximately to Pope John XXIII's I, II and III class feast days.Commemorations were abolished both as a rank of liturgical day and as the addition of a second set of Collect, Secret, and Postcommunion for that commemoration after the Collect, Secret, and Postcommunion of the day at Mass.While some of the memorials are considered obligatory, others are optional, permitting a choice on some days between two or three memorials, or between one or more memorials and the celebration of the feria.