Over time, the use of other languages, once a rare privilege only given to the Slavs of Dalmatia (in present-day Croatia) who used Old Church Slavonic written in Glagolitic characters, has become more common than the use of Latin and Greek. Kyrie eleison ("Lord, have mercy") is the first section of the Mass ordinary. During the Middle Ages, prior to the Council of Trent, the Kyrie was frequently troped: it was common in certain uses of the Roman Rite (such as the Sarum Use) to add tropes to the "Kyrie". The tropes were essentially texts particular to a specific feast day interpolated between the lines of the "Kyrie". English renaissance composers seem to have regarded the Sarum rite Kyrie as part of the propers and begin their Mass settings with the Gloria. The 1970 revision of the Roman Missal has extended the availability of this practice to all Masses (though in a different way). Gloria ("Glory to God in the highest"). The "Gloria" is reserved for Masses of Sundays, solemnities, and feasts, with the exception of Sundays within the penitential season of Lent (to which, before 1970, were added the Ember Days occurring four times a year, and the pre-Lenten season that began with Septuagesima), and the season of Advent (when it is held back as preparation for Christmas). It is omitted at weekday Masses (called ferias) and memorials, and at requiem and votive Masses, but is generally used also at ritual Masses celebrated on occasions such as the administration of another sacrament, a religious profession or the blessing of a church. On May 22, 2019, Pope Francis altered part of the Gloria in Italy, changing from "Peace on earth to people of goodwill" to "Peace on Earth to people beloved by God." The changes, which were first approved by the General Assembly of the Episcopal Conference of Italy, are part of the third edition of the Roman Missal. Credo ("I believe in one God"), the Nicene Creed. The "Credo" is used on all Sundays and solemnities. Until simplified by Pope Pius XII in 1956, the rules (some 400 words in Section XI of the "Rubricae Generales Missalis") were much more complicated, listing, among other Masses, those of Doctors of the Church, those celebrated during octaves and certain votive Masses. The Apostles' Creed may always be substituted.