Collectiones canonum Dionysianae

The Collectiones canonum Dionysianae (Latin for Dionysian collections of canons), also known as Collectio Dionysiana or Dionysiana Collectio ("Dionysian Collection"), are the several collections of ancient canons prepared by a Scythian monk, Dionysius 'the humble' (exiguus). They include the Collectio conciliorum Dionysiana I, the Collectio conciliorum Dionysiana II, and the Collectio decretalium Dionysiana.

Source: Wikipedia — Collectiones canonum Dionysianae (CC BY-SA 4.0)