D.C. Mun. Regs. tit. 23, r. 23-2004
The licensee under a Caterer's license may transport alcoholic beverages within the District of Columbia subject to the requirements of § 1303. The importation of alcoholic beverages by the licensee under a Caterer's license into the District of Columbia from outside of the District of Columbia shall be prohibited pursuant to D.C. Official Code § 25-772, and said alcoholic beverages shall be deemed illegal contraband goods subject to seizure and forfeiture to the District of Columbia pursuant to D.C. Official Code § 25 -911.
The licensee under a Caterer's license shall be permitted to remove sealed containers of alcoholic beverages from an event site, but shall not be permitted to remove unsealed containers from the premises. Customers who purchase or receive alcoholic beverages at the event site shall be permitted to remove sealed containers of alcoholic beverages from the premises and retain possession of unsealed containers on the premises.
Unopened containers of alcoholic beverages purchased from an on-premises licensee, class A, may be returned by the licensee under a Caterer's license either to a class A licensee or stored at a location within the District of Columbia that has been approved by the Board.
D.C. Mun. Regs. tit. 23, r. 23-2004