Maryland Code, Alcoholic Beverages and Cannabis § 30-503

(a) A holder of a wholesaler's license may enter into an agreement with a holder of a per diem license issued under Subtitle 13 of this title to deliver beer on the effective date of the per diem license and accept returns on the same day.

(b) The agreement entered into under subsection (a) of this section shall include the type of equipment, services, personnel, and supplies required to dispense draft beer.