A three-compartment vessel for each of the three holy oils: chrism, oil of catechumens, and oil of the sick. The vessel is often inscribed with the Latin abbreviation for each holy oil: S.C. (sacrum chrisma), O.C. (oleum catechumenorum), and O.I. (oleum infirmorum). It has been in use since the Middle Ages. One set of these oils is kept on reserve in a cathedral, and smaller sets for use in a parish, hospital, or infirmary are kept locked in a cupboard in the sanctuary of each church.