Yes. ABRA doesn’t consider it a cover charge so they would be allowed to, but according to DC Regs it has to be a visible sign which many locations do not have.
710.4 Any holder of a Retailer’s license Class C or D, who makes a permitted minimum charge
for either food or a beverage, shall, during the hours when the minimum charge is made, keep
posted in a conspicuous place at each public entrance to the room or place where the minimum
charge is made a sign stating that a minimum charge is made, the amount of the minimum
charge, and whether the minimum charge shall be applied to food and/or beverage(s).
710.5 The sign required by § 710.4 shall be not less than one square foot in area with lettering
not less than one inch (1 in.) in height, and the letters shall be easily legible.