27 CFR § 4.38a - Bottle cartons, booklets and leaflets.
(a) General. An individual covering, carton, or other container of the bottle used for sale at retail (other than a shipping container), or any written, printed, graphic, or other matter accompanying the bottle to the consumer buyer shall not contain any statement, design, device, or graphic, pictorial, or emblematic representation that is prohibited by §§ 4.30 through 4.39 on labels.
(b) Sealed cartons. If bottles are enclosed in sealed opaque coverings, cartons, or other containers used for sale at retail (other than a shipping container), such coverings, cartons, or other containers must bear all mandatory label information.
(c) Other cartons.
(1) If an individual covering, carton, or other container of the bottle used for sale at retail (other than a shipping container) is so designed that the bottle is readily removable, it may display any information which is not in conflict with the label on the bottle contained therein.
(2) Cartons displaying brand names and/or designations must display such names and designations in their entirety - brand names required to be modified, e.g. by “Brand” or “Product of U.S.A.”, must also display such modification.
(3) Wines for which a truthful and adequate statement of composition is required must display such statement.