A more thorough explanation:

Citatio ad reassumendam causam

Citatio ad reassumendam causam is a legal term that means "citation to take up a cause again." It is used in civil law when a party dies and the action is abated. In this case, a citation is issued to revive the action against the deceased party's heir.

For example, if a person sues another person and the defendant dies before the case is resolved, the case is abated. However, the plaintiff can issue a citatio ad reassumendam causam against the deceased party's heir to revive the case and continue the legal proceedings.