For example, in the US, Part 571 - Federal Motor Vehicle Safety Standards, Section 571.111 S5.4.2. Retrieved 8 March 2023. "Each convex mirror shall have permanently and indelibly marked at the lower edge of the mirror's reflective surface, in letters not less than 4.8 mm nor more than 6.4 mm high the words 'Objects in Mirror Are Closer Than They Appear.'"
