Customary (Liturgy)

A customary is a Christian liturgical book that adapts a ritual family and rite to a particular local context, typically to the customs of a specific church, cathedral, monastery, or religious order. It is generally synonymous with, and sometimes forms part of, a consuetudinary, a book recording the ceremonial forms and regulations used in a community's services and daily practices. Customaries are a key source for the distinctive qualities of medieval local liturgical uses, and in modern contexts the same kind of book may be called a custom book.