21 CFR §516.155

1. (a)The labeling of an indexed drug that is found to be eligible for indexing under § 516.129(c)(7)(i) shall state, prominently and conspicuously: “LEGAL STATUS—In order to be legally marketed, a new animal drug intended for a minor species must be Approved, Conditionally Approved, or Indexed by the Food and Drug Administration. THIS PRODUCT IS INDEXED—MIF # (followed by the applicable minor species index file number and a period).” “Extra-label use is prohibited.” “This product is not to be used in animals intended for use as food for humans or food-producing animals.”
2. (b)The labeling of an indexed drug that is found to be eligible for indexing for use in an early, non-food life stage of a food-producing minor species animal, under § 516.129(c)(7)(ii), shall state, prominently and conspicuously: “LEGAL STATUS—In order to be legally marketed, a new animal drug intended for a minor species must be Approved, Conditionally Approved, or Indexed by the Food and Drug Administration. THIS PRODUCT IS INDEXED—MIF # (followed by the applicable minor species index file number and a period).” “Extra-label use is prohibited.”
3. (c)The labeling of an indexed drug shall contain such other information as may be prescribed in the index listing.