The sacristan held charge of the church and all things necessary to the services. At Saint-Jean, the customary (lectio
31) tells us that he was also called the thesaurarius, or treasurer. The sacristan watched all things in the treasury,
including the relics, altar ornaments, and altar vessels. He was charged to bring out the correct things for each altar
and feast, and was the one to prepare the communion hosts, and to supervise the (separate) washing of vessels and cloths
used in the consecration of the hosts. He rang the bell to mark the canonial hours, and was in charge of the monastic
parish located within the precinct of the abbey. In many communities, the sacristan had assistants: the subsacrist (not
known at Saint-Jean), and a separate treasurer, as well as a vestarer (a position known at Saint-Jean).