Page "Mass (liturgy)" Paragraph 27

All of these books contain such features as meditations for the presiding celebrant ( s ) during the liturgy, and other material such as the rite for the blessing of palms on Palm Sunday, propers for special feast days, and instructions for proper ceremonial order.

These books are used as a more expansively Catholic context in which to celebrate the liturgical use found in the Book of Common Prayer and related liturgical books.