Customary
A book describing the customs - the rituals accompanying liturgical services or monastic discipline, for example - of an ecclesiastical establishment.
A book describing the customs - the rituals accompanying liturgical services or monastic discipline, for example - of an ecclesiastical establishment. A customary is a form of directory and is also known as a consuetudinary or Liber ordinarius.
Michelle Brown. Understanding Illuminated Manuscripts (Malibu, CA: J. Paul Getty Museum in association with the British Library, c1994).