No quality mark shall be applied to any article except in accordance with the following provisions of this section:
The mark shall be so applied that the carat mark shall immediately precede the platinum mark, as for example, "14 K & Plat.," "l8 K & Plat.," as the case may be. If the percentage of platinum exceeds 5 per cent, the quality mark may also include a declaration of the percentage of platinum, as for example, "18 K & l/10 Plat.," or "14 K & l/8 Plat.," or as the case may be.
Ca. Bus. and Prof'l. Code § 22128