D.C. Mun. Regs. tit. 9, r. 9-436
The term "caterer," as used in this chapter, means any person who is engaged in the business of preparing food, meals or beverages, for the purposes of consumption at a place designated by the purchaser.
If a sales agreement with a caterer requires the caterer to prepare and serve food, meals, or beverages, and in addition provides that the caterer shall furnish waiters and other services connected with that preparation and service, the tax shall apply to the total charges, whether or not the charges for preparation and service and the charges for the waiters and other services are separately stated.
The tax does not apply to charges for an announcer, hat check person, doorman, or other person who is not connected with the preparation or service of food, meals, or beverages; Provided, that charges made for the service of these persons must be separately stated on the invoice and the nature of the service must be adequately described.
D.C. Mun. Regs. tit. 9, r. 9-436