 DATE: Father Gionetti gives Father Merrin a copy of the Rituale  Romanum (Roman Ritual). (The administration of exorcism is in Title  X of the Rituale Romanum.) The title of the book embossed on its  leather cover is "Roman Ritual", in English. Later in the film,  Father Merrin asks Joseph to help him by reading passages of the  book, and we are shown a couple of printed pages, the text of which  is also in English. The Rituale Romanum would have been printed in  Latin in 1949, when the film is set, because vulgar translations of  liturgical texts were not authorized until the promulgation of the  Sacrosanctum Concilium (Constitution on the Sacred Liturgy) by Pope  Paul VI on 4 December 1963, as part of the Second Vatican Council.