D.C. Mun. Regs. tit. 31, r. 31-1403
No operator shall provide service or sign into a DPS if either the operator or the vehicle does not have all current and valid licenses required by this title and other applicable laws.
No operator shall provide service while under the influence of illegal intoxicants, or under the influence of legal intoxicants that have been prescribed with a warning against use while driving or operating equipment.
No operator shall solicit or accept a street hail, engage in false dispatch, loiter, cruise, or use a taxicab stand.
No operator shall accept a payment from a passenger, or provide service, unless the amount of the fare (including any gratuity), and the method of payment, comply with all applicable provisions of this chapter and Chapter 16.
No operator shall access or attempt to access a passenger's payment information after the payment has been processed.
D.C. Mun. Regs. tit. 31, r. 31-1403