California Code, Labor Code - LAB § 2676.5

(a) Every person registered as a garment manufacturer shall display on the front entrance of his or her business premise, and also, if the front entrance is within the interior of a building, on or near the main exterior entrance of the building in which his or her business premise is located, his or her name, address, and garment manufacturing registration number, all in letters not less than three inches high.

(b) The Labor Commissioner may waive the requirements of this section if he or she finds compliance to be unfeasible due to the design or layout of a business premise.

(c) This section shall not apply to a showroom or a building containing a showroom if no garment manufacturing or only incidental garment manufacturing is conducted in the showroom or the building.

(d) As used in this section, “showroom” means a room where merchandise is exposed for sale or where samples are displayed.