In the Catholic Church, preconciliar Latin liturgical rites ("preconciliar": before the Second Vatican Council, which began in 1962) coexist with postconciliar rites. In the years following the Second Vatican Council, Pope Paul VI initiated significant changes. Some of Paul VI's contemporaries, who considered the changes to be too drastic, obtained from him limited permission for the continued use of the previous Roman Missal. In the years since, the Holy See has granted varying degrees of permission to celebrate the Roman Rite and other Latin rites in the same manner as before the council. The use of preconciliar rites is associated with traditionalist Catholicism.

In the decades immediately after the Second Vatican Council, each of the various grants of permission to use the preconciliar Roman Rite Mass was in the form of an indult (i.e. a concession). The term universal indult was used to describe a hypothetical broadening of these concessionary permissions, but in his 2007 apostolic letter Summorum Pontificum, Pope Benedict XVI went even further than the proposed "universal indult" by elevating the status of the preconciliar forms beyond that of a concession. In 2021, Pope Francis reinstated restrictions on the use of the Tridentine Mass with his apostolic letter Traditionis custodes.

The simultaneous use of the preconciliar rites alongside the current editions of those same rites has necessitated the development of nomenclature to distinguish the older versions from the newer ones. The preconciliar Roman Rite has been called by a wide variety of names:

To distinguish it from the Mass of Paul VI, the older Roman Rite Mass (that is, the 1962 revision of the Tridentine Mass) has been called at various times the:

The preconciliar Ambrosian Rite has been called the Extraordinary Form of the Ambrosian Rite.

Because the current versions of the rites are far more widely used, they are generally identified using the name of the rite without any further specification, e.g. "Ambrosian Rite". When differentiation is required, the current version is often called the Ordinary Form of the rite. Pope Francis introduced the phrase "unique expression" to refer to the current Roman Rite in contrast to the preconciliar form. The Mass of the current Roman Rite is sometimes called the New Order of Mass (Latin: Novus Ordo Missae) or simply the Novus Ordo.

In June 1971, Pope Paul VI gave bishops permission to grant faculties to elderly or infirm priests to celebrate the older Roman Rite Mass without a congregation. Later that year, Cardinal John Heenan presented Paul VI with a petition signed by 57 scholars, intellectuals, and artists living in England, requesting permission to continue the use of the older Mass. On October 30, 1971, Paul VI granted this permission for England and Wales. Because Agatha Christie was one of the petition's 57 signers whose name Paul VI is said to have recognized, the indult became known as the Agatha Christie indult.

In the 1984 letter Quattuor abhinc annos, the Congregation for Divine Worship and the Discipline of the Sacraments under Pope John Paul II extended to the entire Latin Church the indult for bishops to authorize celebrations of the preconciliar Roman Rite Mass under certain conditions.