Ceremonial

Relating to ceremony, or external rite; ritual; according to the forms of established rites.

Observant of forms; ceremonious. [In this sense ceremonious is now preferred.]

A system of rules and ceremonies, enjoined by law, or established by custom, in religious worship, social intercourse, or the courts of princes; outward form.

The order for rites and forms in the Roman Catholic church, or the book containing the rules prescribed to be observed on solemn occasions.