Cal. Bus. & Prof. Code § 138

Every board in the department, as defined in Section 22, shall initiate the process of adopting regulations on or before June 30, 1999, to require its licensees, as defined in Section 23.8, to provide notice to their clients or customers that the practitioner is licensed by this state. A board shall be exempt from the requirement to adopt regulations pursuant to this section if the board has in place, in statute or regulation, a requirement that provides for consumer notice of a practitioner’s status as a licensee of this state.