A more thorough explanation:

Definition: Registrarii Liber is a historical term that refers to the register's book in chancery that contains all decrees. It is abbreviated as reg. lib. Registrarius, on the other hand, is a Latin term that refers to a registrar or register, which is a notary.

• The Registrarii Liber was used in chancery to keep track of all the decrees made by the court.
• The Registrarius was responsible for keeping records of important legal documents.

These examples illustrate how Registrarii Liber and Registrarius were used in the past to keep track of important legal documents and decrees. They were essential in ensuring that important information was recorded and easily accessible for future reference.