(a) Basic requirements. A proprietor must place the marks prescribed by this subpart on cases, encased containers, and packages of spirits and denatured spirits so that they are:

1. (1) Of adequate size to be easily read;
2. (2) Of a color in distinct contrast to the color of the background;
3. (3) Legible; and
4. (4) Durably affixed.

(c) Location. A proprietor must place the prescribed marks on one side of the case or encased container, or on the head of the package.

(26 U.S.C. 5206)