Prior to collection, during collection, during transportation and until the contents have been emptied therefrom, each can intended for use or used for milk drippings, milk rinsings, mixtures or combinations thereof shall have securely attached thereto a red tag not less than 2″ × 4″ in size upon which shall be printed conspicuously in block letters at least one-half inch in height the words “Milk Drippings,” “Milk Rinsings” or “Mixture,” or any combination of such words which will properly describe the contents of the can. The name and address of the operator of the plant where such products were recovered, the location of the plant, the name of the collector and the date of collection or recovery shall be plainly printed or stamped upon each such tag.