Cal. Penal Code § 580

Every person mentioned in this chapter, who issues any second or duplicate receipt or voucher, of a kind specified therein, at a time while any former receipt or voucher for the merchandise specified in that second receipt is outstanding and uncanceled, without writing across the face of the same the word “Duplicate,” in a plain and legible manner, is punishable by imprisonment pursuant to subdivision (h) of Section 1170, or by a fine not exceeding one thousand dollars ($1,000), or both.