The National Fire Alarm Code (NFPA 72) establishes minimum requirements for the application of fire alarm notification. As stated, the requirements for when they are to be provided are not contained in NFPA 72, but rather in the appropriate building or fire code adopted by the jurisdiction.  

Design requirements differ depending on whether the system is intended for public mode public mode
Public mode operation is intended to notify all occupants of the building or area protected by the fire alarm system. A fire alarm system that actuates and sounds horns throughout the building, and is intended to alert all occupants to evacuate is an example of a fire alarm system operating in the public mode. operation or private mode operation.