Signal, Supervisory 1 : A signal indicating the need for action in connection with the supervision of guard tours, the fire suppression systems or equipment, or the maintenance features of related systems
NFPA 1 Fire Code, National Fire Protection Association (NFPA), MA, USA 2009 ed. https://law.resource.org/pub/us/code/ibr/nfpa.1.20 03.pdf, (Code: Nat Fire Protection Association Fr&LfSf Requir - Amer) {171 NFC}