Okla. Admin. Code § 45:30-5-15
All vehicles owned or leased and made use of by Beer Distributors, their agents, or employees, Small Brewer Self-Distributors, or Brewpub Self-Distributors, except licensed carriers under the Oklahoma Alcoholic Beverage Control Act, shall have displayed on the outside of the doors, windows or side panel on both sides of the vehicle a sign in letters at least three (3) inches in height and one and one-half (1 1/2) inches in width stating the letters A.B.L.E. and the license number. The name and address of the Beer Distributor, Small Brewer Self-Distributor, or Brewpub Self-Distributor may be printed in letters of lesser dimensions. Signage in smaller dimensions for vehicles belonging to Beer Distributors, their agents, or employees may be placed on the inside front dashboard of the vehicle in a location clearly visible from outside the vehicle. These signs shall be properly displayed while transporting any beer or brewed products by the Beer Distributor, Small Brewer Self-Distributor, or Brewpub Self-Distributor from the Brewer or Nonresident Seller or to all Retail Spirit, Retail Beer, Mixed Beverage, Caterer or Special Event licensees.
Okla. Admin. Code § 45:30-5-15