Cal. Health & Safety Code § 1797.180

No agency, public or private, shall advertise or disseminate information to the public that the agency provides EMT-II or EMT-P rescue or ambulance services unless that agency does in fact provide this service on a continuous 24 hours-per-day basis. If advertising or information regarding that agency’s EMT-II or EMT-P rescue or ambulance service appears on any vehicle it may only appear on those vehicles utilized solely to provide that service on a continuous 24 hours-per-day basis.