Papal DecretalsThe term decretal ˗ epistola decretalis, littera decretalis ˗ is used to describe a papal ruling, especially on ruling on ecclesiastical discipline, or a rescript (rescriptum) in response to an request for a norm. A decretal may be distinguished from a privilege that was granted to an ecclesiastical institution or person.
By the twelfth century a decretal more generally meant a decision rendered on a case that had been appealed to Rome, i.e. an appellate decision.
Decretals were collected into collections and placed on an equal footing with conciliar canons ca. 500.
Sircius' decretal letter marks the beginning of the papacy adopting the legislative and judicial vocabulary of secular Roman Law.
Pope Hormisdas (514-523) Commissioned Dionysius Exiguus to compile a canonical collection, later called the Collectio Dionysiana
Latin Text of Siricius's Decretal
Latin Text in Sankt Gallen, Stiftsbibliothek 671, fol. 220-228 (Ninth Century): Collectio canonum Dionysio-Hadrianaan
Latin Collections of Canon Law