(a) The sliding scale method of expressing any guaranteed analysis (for example, “protein 15-18%”) is prohibited.

(b) The label of any pet food or specialty pet food, which is formulated as and represented to be a vitamin supplement, shall include a guarantee of the minimum content of each vitamin declared in the ingredient statement. Such guarantees shall be stated in units of measurements established by a recognized authority on animal nutrition.

(c) The vitamin potency of any pet food or specialty pet food distributed in any container smaller than one pound may be guaranteed in such units per ounce as established by a recognized authority on animal nutrition.

(d) If the label of any pet food or specialty pet food does not represent such food to be either a vitamin or a mineral supplement, but does include a table of comparison of a typical analysis of the vitamin, mineral, or nutrient content of such food with levels recommended by a recognized animal nutrition authority, such comparison may be stated in the units of measurement used by such authority. Any table of comparison of any vitamin, mineral, or nutrient content shall constitute a guarantee, but need not be repeated in the guaranteed analysis. Such table of comparison may appear on the label separate and apart from the guaranteed analysis.