His successor, Pope John XXIII, issued a new typical edition of the Roman Missal in 1962. This incorporated the revised Code of Rubrics which Pope Pius XII's commission had prepared, and which Pope John XXIII had made obligatory with effect from 1 January 1961. In the Missal, this Code of Rubrics replaced two of the documents in the 1920 edition; and the Pope's motu proprio "Rubricarum instructum" took the place of the superseded Apostolic constitution "Divino afflatu" of Pope Pius X.