The name of the facility, city, state, ZIP Code, and name of the operator shall be legible and clearly visible to patrons. The facility name shall be in letters at least three inches high, and shall be of a color contrasting with the surface on which it is posted. Letters and numbers for the city, state, and ZIP Code, may not be less than one inch in height.
Source:
Section 114337, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=114337..