D.C. Mun. Regs. tit. 19, r. 19-1205
A sightseeing tour guide, while engaged in performing services as a sightseeing tour guide, shall conspicuously wear a badge bearing the licensee's license.
No sightseeing tour guide shall cause a customer to be taken to a point of interest without providing that the customer shall be taken from that location to the next point of interest to be visited in the course of the sightseeing tour. This provision shall not apply if:
No licensed sightseeing tour guide shall conduct a sightseeing tour unless the fees for the sightseeing tour have been disclosed in writing prior to the start of the tour.
No sightseeing tour guide shall charge or attempt to charge a sum greater than the original charge for the tour, whether in payment for unsolicited merchandise, meals, or services, or for any other reason. This provision shall not apply if the customer specifically authorizes additional services from the sightseeing tour guide.
A sightseeing tour guide licensee shall notify the Department within thirty (30) days after any change to the information provided on the application required by § 1203, including a change to the business address or telephone number of the licensee.
D.C. Mun. Regs. tit. 19, r. 19-1205