"An extraordinary form of the Roman Rite" is a phrase used in Pope Benedict XVI's motu proprio Summorum Pontificum to describe the liturgy of the 1962 Roman Missal, widely referred to as the Tridentine Mass. The phrase distinguishes the liturgy of the Missal issued by Pope John XXIII in 1962 from that of the Missal revised by Pope Paul VI in 1969 (the "ordinary form"), which "obviously is and continues to be the normal Form – the Forma ordinaria – of the Eucharistic Liturgy".