Indult

An indult in Catholic canon law is a permission, or privilege, granted by the competent church authority – the Holy See or the diocesan bishop, as the case may be – for an exception from a particular norm of church law in an individual case, for example, members of the consecrated life seeking to be dispensed from their religious vows, or of priests and deacons who voluntarily seek to return to the lay state (usually to marry). An apostolic indult is needed from the local ordinary for presbyteral or diaconal ordinations done within a year before the normal date; if the ordination is done more than one year in advance of the normal date then a papal apostolic indult from the Holy See (through the Congregation for Catholic Education, the Congregation for the Clergy, or the Congregation for Religious in the Roman Curia) is also needed.

The best-known indult among lay Catholics in recent times was the one granted by Pope John Paul II in 1984 authorising the world's bishops to permit celebrations of the Tridentine Mass liturgy in their dioceses. This indult gave rise to the term "indult Catholics", referring to Catholics who attended such celebrations. This indult was superseded in 2007 by new legislation introduced by Pope Benedict XVI in the motu proprio Summorum Pontificum.

...
Wikipedia