The so-called Decretum Gelasianum or Gelasian Decree was traditionally attributed to the prolific Pope Gelasius I, bishop of Rome 492–496. In surviving manuscripts the Decretal exists on its own and also appended to a list of books of Scripture titled as attested as canonical by a Council of Rome under Pope Damasus I, bishop of Rome 366–383. Since that list contains a quotation from Augustine, writing about 416, it is evident that the title Incipit Concilium Vrbis Romae sub Damaso Papa de Explanatione Fidei, the so-called Damasine List, is of no historical value.
The Decretal include a list of works adjudged apocryphal "by Pope Gelasius and seventy most erudite bishops." Though the ascriptions are generally agreed to be apocryphal themselves, except among the most traditional of apologists, perhaps reflecting the seventy translators of the Septuagint and the seventy apostles sent out in Luke, this list de libris recipiendis et non recipiendis ("of books to be admitted and not to be admitted"), probably originating in the 6th century, represents a tradition that can be traced back to Pope Damasus I and reflects Roman practice in the development of the Biblical canon. In the list of gospels, the order is given as Matthew, Mark, Luke, John. Fourteen epistles are credited to Paul including Philemon and Hebrews. Of the General Epistles seven are accepted: two of Peter, one of James, one of the apostle John, two of " the other John the elder" (presbyter), and one of "Judas the Zealot".
The Decretum is in several parts: the second part is a canon catalogue, and the fifth part is a catalogue of the 'apocrypha' and other writings which are to be rejected. The canon catalogue gives 26 books of the New Testament, 2nd Corinthians is not mentioned. (Parts 1, 3, and 4 are not relevant to the canon.)