26 USC 5180 - Signs

(a) Requirements 
Every person engaged in distilled spirits operations shall place and keep conspicuously on the outside of his place of business a sign showing the name of such person and denoting the business, or businesses, in which engaged. The sign required by this subsection shall be in such form and contain such information as the Secretary shall by regulations prescribe.
(b) Penalty 
For penalty and forfeiture relating to failure to post sign or improperly posting such sign, see section 5681.