NFPA 1 Fire Code 2018:
10.11 Fire Protection Markings
10.11.1 Premises Identification.
10.11.1.1 New and existing buildings shall have approved address numbers placed in a position to be plainly legible and visible from the street or road fronting the property.
10.11.1.2 Address numbers shall be a minimum of 4 inches (100 mm) high with a minimum stroke width of 1/2 inches (13 mm).
10.11.1.3 Telecommunications equipment utilized to communicate address data to E911 communication centers shall be programmed and maintained to accurately convey such address information to the E911 communication center.
10.11.1.4 The assignment of addresses to buildings shall be in accordance with a method approved by the *AHJ.
10.11.1.5 Addresses shall not be changed unless approved by that *AHJ.
10.11.1.6 Address numbers for suites within a multiple tenant building or complex shall be individually identified in a manner approved by the *AHJ.
10.11.1.7 Address numbers shall contrast with their background.
10.11.1.8 Address numbers shall be arabic numerals or alphabet letters.
1.3.2 Referenced Standards.
18.104.22.168 Where no applicable codes, standards, or requirements are set forth in this Code or contained within other laws, codes, regulations, ordinances, or bylaws adopted by the authority having jurisdiction (*AHJ), compliance with applicable codes and standards of NFPA or other nationally recognized standards, as are approved, or approved performance based options in accordance with Chapter 5, shall be deemed as prima facie evidence of compliance with the intent of this Code.