California Code, Business and Professions Code - BPC § 25170

Any person who delivers to the premises of any on- or off-sale general licensee, or any on- or off-sale general licensee who has upon his licensed premises, or any person who possesses any distilled spirits the container of which does not bear a label plainly indicating the quantity and proof strength of the contents and the name of the manufacturer, rectifier, importer, or wholesaler thereof is guilty of a misdemeanor.  To the extent that such information is blown into the glass of the container, it constitutes a compliance with this section.