Altar cards

[1] They contain certain prayers that the priest must say during the Mass, and their only purpose is as a memory aid, although they are usually very beautifully decorated.

[1] When Pope Pius V restored the Missal, only the card at the middle of the altar was used, and it was called the "Tabella Secretarum".

[1] The altar card on the left contains the Last Gospel (John 1:1–14), which is said at the very end of the Mass.

The card on the right contains the prayer for blessing the wine and water ("Deus qui humanæ substantiæ") and the Lavabo ("I shall wash", from the words of Psalm 26[25 in the Septuagint/Vulgate]:6–12).

The larger, centre card contains the Gloria, the prayer Munda cor meum recited before reading the Gospel, the Credo, the prayer for offering the Host (Suscipe, Sancte Pater), the Words of Consecration, and portions of the Canon of the Mass.