Originally within the United Kingdom the title of diocesan record office would frequently have referred to a church-owned diocesan registry or chancery. This would have been where the episcopal registers, administrative papers and title deeds were preserved under the general superintendence of the diocesan chancellor.
In modern usage it generally refers to an approved repository, frequently operated by a local authority, which has been specially designated by a Church of England bishop for the collection and preservation of historic archives, both from the diocese and also from local ecclesiastical parishes.