We have the answer! B&P Code section 22940:
22940. It shall be unlawful for any business to use words expressly referencing an individual's marital status as part of the individual's mailing address on a billing tatement, related correspondence, enclosing envelope, or any solicitation for new business. This shall not prohibit the use of the prefix "Mr.," "Mrs.," "Ms.," or "Miss."
22941. Any violation of this chapter shall be punishable by a civil penalty of up to two hundred fifty dollars $250) for each violation.
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