Regula
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
Lat In practice. A ruin. Regula generalis, a general rule; a standing rule or order of a court Frequently abbreviated, "Reg. Gen."
— Regula Catoniana. In Roman law. The rule of Cato. A rule respecting the validity of dispositions by will. See Dig. 34, 7.