Quattuor abhinc annos (Latin for "four years ago") is the incipit of a letter that the Congregation for Divine Worship and the Discipline of the Sacraments sent on 3 October 1984 to presidents of episcopal conferences concerning celebration of Mass in the Tridentine form.The Congregation subsequently granted diocesan bishops an indult to authorize specified priests and groups of the faithful who requested it, celebration of the Tridentine Mass according to the 1962 Roman Missal promulgated by Pope John XXIII.[3] An important condition for granting the requests was "that it be made publicly clear beyond all ambiguity that such priests and their respective faithful in no way share the positions of those who call in question the legitimacy and doctrinal exactitude of the Roman Missal promulgated by Pope Paul VI in 1970.The view that use of the earlier form of the Roman liturgy had never been formally abrogated[5] was authoritatively confirmed by Pope Benedict XVI, who declared that permission to use it (which can be granted by the priest in charge of the church) is required only for public celebration.[6] Pope Benedict XVI revoked the directives on 7 July 2007, replacing them with the norms enunciated in his motu proprio Summorum Pontificum.