California Code, Health and Safety Code - HSC § 18026

(a) All manufactured homes, mobilehomes, commercial coaches, and special purpose commercial coaches manufactured on or after September 1, 1958, that are sold, offered for sale, rented, or leased within this state shall bear a federal label or an insignia of approval issued by the department, whichever is appropriate, to indicate compliance with the regulations of the department adopted pursuant to this part, which were in effect on the date of manufacture of the manufactured home, mobilehome, commercial coach, or special purpose commercial coach.

(b) The department may issue insignia for manufactured homes, mobilehomes, commercial coaches, or special purpose commercial coaches manufactured prior to the effective dates of the appropriate regulations that meet the requirements of reasonable standards of health and safety as set forth in this part or the regulations adopted pursuantto this part in effect at the time of that issue.

(c) It is unlawful for any person to remove, or cause to be removed, an insignia of approval affixed pursuant to this section without prior authorization by the department.