The commonly measured license or measurement permission act referred to in the Roman Catholic Church permission of the local bishop for the regular celebration of Eucharistic celebrations in semi-public or private chapels . Permission is granted on request by the locally responsible bishop and requires appropriate equipment.
Even in the early Church, celebrating Holy Mass in private homes or in small groups was a problem. The synod of Laodicea in the 4th century forbade the celebration of the Eucharist at home, in other regions an episcopal permission was required. Since the early Middle Ages, the house chapel with a house chaplain, the “castle priest”, had become common on noble mansions, and this led to abuses. Also in order to underline the obligation to attend church services in the parish church, there have been repeated attempts to regulate the church, such as a restriction to church services with the sick. The Decretum Gratiani (around 1140, C. XXXIII) handed down: Unicuique fidelium licet in domo sua oratorium habere, et ibi orare; missas autem ibi celebrare non licet , "Every believer is allowed to have a prayer room in his home, but celebrating masses there is not allowed." The Council of Trento (sessio XXII., 1562/63) also banned masses in private homes.
Until the Codex iuris Canonici came into force in 1917, however, there was a legal development that led to can. 1195 of the CIC led: In oratoriis domesticis […] celebrari potest, postquam Ordinarius oratorium visitaverit et probaverit ad normam can. 1192, p2, unica Missa, eaque lecta, singulis diebus, exceptis festis sollemnioribus; sed aliae functiones ecclesiasticae ibidem ne fiant , “In house chapels  a holy mass can be read after the bishop has given it within the framework of the regulations of c. 1192 attended and examined a missa lecta on individual days, but not on feast days; other ecclesiastical activities should not take place there. ” High offices , baptisms and other worship services are therefore excluded.
According to canon law, which was renewed in 1983, in semi-public chapels erected with the permission of the episcopate, “all worship services are permitted unless restrictions are imposed by law or by regulation of the local ordinary or if liturgical norms are contrary” (CIC can. 1225); in (non-public) private chapels “the permission of the local ordinary is required to celebrate mass or other worship services” (can. 1228).
- Celebret : The litterae commandatitiae , a certificate from the bishop or religious superior, called a celebret , with which priests can identify themselves when celebrating Holy Mass in foreign churches, was sometimes referred to as a "mass license".