D.C. Code § 50-2444
Directory of vehicle identification tags.
(a) Within 90 days after the applicability date of this section, the Mayor shall establish, and thereafter maintain, a directory of all vehicle identification tags issued by U.S. states and territories.
(b) The Mayor shall establish procedures for identifying tags as legitimate and ensure that all District employees tasked with enforcement of parking and moving violations are adequately trained in the proper verification of vehicle identification tags.