n.A register containing unique, consecutive numbers assigned to records and including additional information about the identity of persons involved and the documentary context of the record.
Citations
MacNeil 1995, p. 26 The purpose of registers [in Italy known as protocol registers] is to control the stages of distribution and transit for every official document that passes through the registry. The protocol register, for example, records the document's protocol number (i.e., a unique identifier), the name and official title of the sender, the protocol number in the office of the sender (if applicable), the nature of the action, and indication of any enclosures and their types, the assigned classification number, and the office handling the matter.
