§1. A diocesan bishop is to take care that the acts and documents of the archives of cathedral, collegiate, parochial, and other churches in his territory are also diligently preserved and that inventories or catalogs are made in duplicate, one of which is to be preserved in the archive of the church and the other in the diocesan archive.
§2. A diocesan bishop is also to take care that there is an historical archive in the diocese and that documents having historical value are diligently protected and systematically ordered in it.
§3. In order to inspect or remove the acts and documents mentioned in §§1 and 2, the norms established by the diocesan bishop are to be observed.
Source: Code of Canon Law (Vatican.va)