No person in the City shall advertise or hold himself out to the public as a plumber, or as a licensed plumber, when such person does not have a license as provided for in this Plumbing Code.
No person not in legal possession of a valid master plumber's license issued by the City shall engage in or represent himself as a master plumber in the City, or expose or use a sign with the words "master plumber" or "plumber" thereon, or advertise with similar words for the purpose of implying that he/she is a master plumber or a plumber.
(1957 Code §1127.15)