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Banns of marriage - Wikipedia, the free encyclopedia
In short: "marriage banns [...] are the public announcement in a Christian parish church of an impending marriage between two specified persons. It is commonly associated with the Church of England and with other denominations whose traditions are similar; the Roman Catholic Church abolished the requirement in 1983 .
The purpose of banns is to enable anyone to raise any canonical or civil legal impediment to the marriage, so as to prevent marriages that are invalid. Impediments vary between legal jurisdictions, but would normally include a pre-existing marriage that has been neither dissolved nor annulled, a vow of celibacy, lack of consent, or the couple's being related within the prohibited degrees of kinship".