Cal. Bus. & Prof. Code § 17773

Nothing in this chapter, nor in this code, shall be construed to require that the cash or merchandise value of trading stamps be stated or set forth on any sign, statement, or other advertising media that either advertises or offers those stamps, or advertises or indicates the price of gasoline or motor fuel, whether on any dispensing apparatus or elsewhere, and that is displayed at or about any place of business offering for sale or selling gasoline or other motor vehicle fuel.