A consuetudinary (Med. Lat. consuetudinarius) is the name given to a ritual book containing the consuetudines—forms and ceremonies—used in the service of a particular monastery, religious order, or cathedral. Often, over long periods of time, religious orders would develop unique liturgical approaches and such would be reflected in the written consuetudinary.
Notable examples of consuetudinary books include:
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.