The links shown below demonstrate the need to comply with 3RCNY 505-01 “Apartment and Guest Room Identification and Directional Markings and Signs,” and 3 RCNY 505-02, entitled “Apartment, Guest Room and Stairwell Fire Emergency Markings”
http://nypost.com/2016/03/21/fdny-may-require-nyers-mark-apartments-with-additional-signs/
https://www.rt.com/usa/371326-nyc-high-rise-fire-injuries/