D.C. Mun. Regs. tit. 9, r. 9-430
In addition to events listed in the Act, the tax on admissions to public events shall apply to (but is not limited to) admission charges for trade shows, boat shows, home shows, horse shows, and dog shows.
Charges for the use of recreational facilities by persons participating in athletic events, and dues or initiation fees for admission to social clubs shall be exempt from the tax.
Cover or minimum charges by restaurants and other establishments for the sale of food or drink are considered part of the charge for food or drinks consumed on the premises and shall not be taxable as admissions.
If discounts are allowed to sales agents as compensation for sales of tickets, those discounts are considered to be a selling expense which may not be deducted in determining the amount of taxable receipts.
D.C. Mun. Regs. tit. 9, r. 9-430