CUSTOMS (CONSUETUDINES). – These are particular regulations designed to ensure uniformity in sacred functions, rendered necessary, especially in large churches, as the rite developed. In monasteries, such customs (known in other Churches as *ordines*) were variously named according to the monastery of origin, e.g., *Consuetudines Cluniacenses*, *Farfenses*, etc. These were transmitted as a heritage to newly founded, affiliated, or reformed monasteries to maintain unity and ensure that all sacred functions were performed in the same manner. The *Consuetudines* of Montecassino were always considered of particular importance as preservers of the most ancient and authentic traditions.
BIBL.: B. Albers, *Consuetudines monasticae*, I-V, Stuttgart and Montecassino 1900-11; St. Kainz, *Die Consuetudines Schyrenses*, in *Studien und Mitteilungen aus dem Benediktiner- und Cisterzienserorden*, 19 (1903-1904), p. 661; S. Eisenhofer, *Handbuch der Katholischen Liturgik*, I, Freiburg 1932, pp. 108-10; F. Oppenheim, *De libris liturgicis deque iure ex eis manante*, Turin 1940, p. 53, n. 2.