California Code, Health and Safety Code - HSC § 108870

(a) Except as provided in subdivisions (c) and (d), each piece of tableware sold, or offered for sale, in this state shall be permanently and indelibly marked with the name of the manufacturer or importer responsible for the sale of the tableware in California.

(b) For the purposes of this section, permanently and indelibly marked means fired or manufactured into the glazed tableware.

(c) This section shall not apply to any tableware that is manufactured without lead or cadmium as an intentionally added ingredient or as an unintentional contaminant.

(d) This section shall not apply to any tableware product that is of a peculiar structure or too small to accommodate the name of the manufacturer or importer in accordance with subdivision (a), provided that the product either (1) is permanently and indelibly marked with a registered trademark that is on file with the department, or is described and depicted in a certificate of registration that is on file with the department, or (2) is part of a tableware set or pattern, one or more pieces that are marked in accordance with subdivision (a).