No person shall sell, offer for sale, or expose for sale shell eggs from a bulk lot which is not plainly marked with a placard having letters no less than one-half inch high designating the correct grade and size or weight class of the bulk lot in accordance with the standards adopted by this state, provided that a bulk lot of shell eggs which has not been graded for quality or which fails to meet the requirements of a grade adopted by this state:

1. (A) Shall be plainly marked with a placard having letters no less than one-half inch high which states "ungraded" or "unclassified";
2. (B) May be plainly marked with a placard having letters no less than one-half inch high which states "mixed size" in lieu of stating a standard size or weight class adopted by this state, if the eggs average twenty-one ounces or more per dozen.