27 CFR § 5.152 - Imitations.
(a) Imitations must bear, as a part of the designation thereof, the word “imitation” and include the following:
(1) Any class or type of distilled spirits to which has been added coloring or flavoring material of such nature as to cause the resultant product to simulate any other class or type of distilled spirits;
(2) Any class or type of distilled spirits (other than distilled spirits specialty products as defined in § 5.156) to which has been added flavors considered to be artificial or imitation.
(3) Any class or type of distilled spirits (except cordials, liqueurs and specialties marketed under labels which do not indicate or imply that a particular class or type of distilled spirits was used in the manufacture thereof) to which has been added any whisky essence, brandy essence, rum essence, or similar essence or extract which simulates or enhances, or is used by the trade or in the particular product to simulate or enhance, the characteristics of any class or type of distilled spirits;
(4) Any type of whisky to which beading oil has been added;
(5) Any rum to which neutral spirits or distilled spirits other than rum have been added;
(6) Any brandy made from distilling material to which has been added any amount of sugar other than the kind and amount of sugar expressly authorized in the production of standard wine; and
(7) Any brandy to which neutral spirits or distilled spirits other than brandy have been added, except that this provision shall not apply to any product conforming to the standard of identity for blended applejack.
(b) If any of the standards set forth in paragraphs (a)(1) through (7) of this section apply, the “Imitation” class designation must be used in front of the appropriate class as part of the designation (for example, Imitation Whisky).