Jus novum (c. 1140-1563) Jus novissimum (c. 1563-1918) Jus codicis (1918-present) Other Sacraments Sacramentals Sacred places Sacred times Supra-diocesan/eparchal structures Particular churches Juridic persons Philosophy, theology, and fundamental theory of Catholic canon law Clerics Office Juridic and physical persons Associations of the faithful Pars dynamica (trial procedure) Canonization Election of the Roman Pontiff Academic degrees Journals and Professional Societies Faculties of canon law Canonists Institute of consecrated life Society of apostolic life A celebret, in Catholic canon law, is a letter from a bishop or religious superior authorizing a priest to say Mass in a/an (arch)diocese other than his own.
xvi on Reform) lays down the rule that "no cleric who is a stranger shall without letter commendatory from his own ordinary be admitted by any bishop to celebrate the divine mysteries".
One who has his celebret in due form, or who is certainly known to be in good standing in his own diocese, may be allowed to celebrate until he has had sufficient time to comply with this rule.
In the United States, the Third Plenary Council of Baltimore, as a regulation against collectors of funds for other (arch)dioceses or countries, enacted a decree (No.
The absence of the celebret does not suffice denial of permission to say Mass, if persons worthy of belief bear positive testimony to the good standing of the priest.