A customary is a Christian liturgical book containing the adaptation of a ritual family and rite for a particular context, typically to local ecclesiastical customs and specific church buildings. A customary is generally synonymous to and sometimes constituent of a consuetudinary (Latin: consuetudinarius or consuetudinarium) that contains the totality of the consuetudines—ceremonial forms and regulations—used in the services and community practices of a particular monastery, religious order, or cathedrals. The distinctive qualities of medieval liturgical uses are often described within customaries.[1] In modern contexts, a customary may also be referred to as a custom book.[2]