In Catholic canon law, an interdict is an ecclesiastical censure, or ban that prohibits persons, certain active Church individuals or groups from participating in certain rites, or that the rites and services of the church are banished from having validity in certain territories for a limited or extended time.
Before 1983, interdicts were either personal, if applied directly to a person, wherever he was, or local, if applied directly to a locality and only indirectly to the people in that place whether permanently or only on a visit. Only the Holy See was empowered to impose a general interdict on a diocese or state or a personal interdict on the people of a diocese or country, but bishops too could impose a general interdict on a parish or on the people of a parish or a particular interdict on a place (such as a church or oratory, an altar or a cemetery) or a person.
A local interdict forbade in general the public celebration of sacred rites. Exceptions were made for the dying, and local interdicts were almost entirely suspended on five feasts of the year: Christmas Day, Easter Sunday, Pentecost, Corpus Christi and the feast of the Assumption of Mary. Besides, in the case of a general local interdict, it remained permissible to celebrate in the cathedral or the only church in a town, but without any solemnity such as the ringing of bells and the playing of music, Mass, baptism, confession, and marriage.
Those who were under personal interdict were forbidden to be present at any religious rite except the preaching of the word of God. While mere attendance ("passive assistance," with "assistance" being an obsolete translation of Latin adsistere/assistere ["be present"; cf. the modern Italian equivalent and its Spanish cognate asistir]) by them did not require that they be expelled, if they were well known to be under interdict they were to be prevented from taking an active part.
An interdict today has the effect of forbidding the person concerned to celebrate or receive any of the sacraments, including the Eucharist, or to celebrate the sacramentals. One who is under interdict is also forbidden to take any ministerial part (e.g., as a reader if a layperson or as a deacon or priest if a clergyman) in the celebration of the Eucharist or of any other ceremony of public worship.
These are the only effects for those who have incurred a latae sententiae interdict, namely, one incurred automatically at the moment of committing the offence for which canon law imposes that penalty. For instance, a priest may not refuse Communion publicly to those who are under merely automatic interdict, even if he knows that they have incurred this kind of interdict - unless the cause for the interdict is known to the priest not only privately but publicly, and is persistent, in which case (though not technically by reason of the interdict) people are to be withheld Communion by force of can. 915.
However, in the case of a ferendae sententiae interdict, one incurred only when imposed by a legitimate superior or declared as the sentence of an ecclesiastical court, those affected are not to be admitted to Holy Communion (see canon 915), and if they violate the prohibition against taking a ministerial part in celebrating the Eucharist or some other ceremony of public worship, they are to be expelled or the sacred rite suspended, unless there is a grave reason to the contrary. In the same circumstances, local ordinaries and parish priests lose their right to assist validly at marriages.
Automatic (latae sententiae) interdict is incurred by anyone using physical violence against a bishop, as also by a person who, not being an ordained priest, attempts to celebrate Mass, or who, though unable to give valid sacramental absolution, attempts to do so, or hears a sacramental confession. Automatic interdict is also incurred by anyone falsely accusing a priest of soliciting sexual favours in connection with confession or attempting to marry while having a perpetual vow of chastity.
An interdict is also the censure that canon law says should be imposed on someone who, because of some act of ecclesiastical authority or ministry publicly incites to hatred against the Holy See or the Ordinary, or who promotes or takes up office in an association that plots against the Church, or who commits the crime of simony.
Interdiction featured in 20th century Maltese politics. Between 1930 and 1933, those who voted for the progressive Compact parties (Constitutional Party, Labour Party) were interdicted and refused burial in sacred grounds.
Once again, between 1961 and 1969, the National Executive of the Malta Labour Party was interdicted and voting Labour became a mortal sin. Among other sanctions, Labour voters were refused absolution, last rites and burial in sacred grounds. During this period, most Labour rallies were disturbed by members of Catholic organisations (that formed the "Diocesan Junta") and the ringing of church bells. A large number of labourites left the Maltese Islands during this period, partly due to the fact that at the time a reference letter from the local parish priest was commonly requested by employers. The 1969 Peace Agreement between the Labour Party and the local Catholic authorities stipulates that the interdiction should not be imposed in the future.
In Malta between 8 April 1961 and 4 April 1969 the leadership of the Malta Labour Party, readers, advertisers and distributors of Party papers as well as its voters were interdicted by the local bishop. Previously, between 1930 and 1933 interdiction was imposed on the Constitutional Party and Labour. In both cases, the Nationalist Party won elections while its opponents were interdicted.
Bishop René Henry Gracida of Corpus Christi, Texas interdicted a Roman Catholic politician in the late 20th century for supporting legal abortion; the unnamed individual died while under interdict.
In Scots law, "an interdict is a civil court order that tells a person not to do something or to stay away from you, your children or a specific place, such as your house. If a person doesn't stick to an interdict, the police might be able to arrest them if the interdict gives them the power to do so" similar to an injunction.