(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) Of adequate size to be easily read;

(2) Of a color in distinct contrast to the color of the background;

(3) Legible; and

(4) Durably affixed.

(b) Use of labels. A proprietor may use labels as the means for applying prescribed marks if the labels meet the requirements of paragraph (a) of this section.

(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)