A more thorough explanation:

Term: REG. BREV.

Definition: An abbreviation for "REGISTRUM BREVIUM," which is a Latin term meaning "register of writs."

Example: In medieval England, the king's chancery kept a REG. BREV. to record all the writs issued by the court.

The term REG. BREV. is an abbreviation for the Latin term "REGISTRUM BREVIUM," which means "register of writs." In medieval England, the king's chancery kept a REG. BREV. to record all the writs issued by the court. This was an important document that helped to ensure that the court's decisions were properly recorded and could be referred to in the future. The use of Latin abbreviations was common in medieval legal documents, and they are still used today in some legal contexts.