D.C. Mun. Regs. tit. 31, § 503
503.1 Each taxicab, except independently operated taxicabs, shall bear on each rear door:
(a) An identifying design or trade name or the name of the owner or company operating the taxicab;
(b) The word "taxicab" or "cab" (unless that word is included in the owner's name or identifying design or trade name); and
(c) The taxicab fleet number.
503.2 No association shall operate under any trade name using any word as "company," "corporation," or the like; provided, that an individual owner of a taxicab who has filed with the Office a written authorization from a company to use its identifying design may, during the effectiveness of the authorization, have the identifying design and name of that company on the taxicab for which it is authorized.
503.3 There shall not be placed on or in any taxicab any lettering, identifying design, word or symbol which has, tends to have, or may have the effect of confusing, misleading or deceiving the public.
503.4 Except as to identifying designs, logos, letters or trade names approved by the Commission, all numbers, excluding telephone numbers, shall be Gothic in style, three inches (3 in.) high and of solid paint stroke width of three-eight inch (3/8 in.).
503.5 No taxicab shall have a fleet number larger than the number of taxicabs in the fleet (with allowance for a reasonable number of vacancies), and the fleet number shall be placed on each rear door under and apart from the insignia or trade name and on the right rear of the body of the taxicab so as to be clearly visible from the rear.
503.6 No lettering, other than as set forth in this section, shall be placed on any taxicab without the approval of the Commission.
503.7 No taxicab shall bear any trade name, identifying insignia, logo or color scheme not previously approved for it by the Commission.
503.8 An association or owner of twenty (20) or more taxicabs may, upon approval of the Commission, use a unique or special color scheme, with or without an identifying insignia or logo, to distinguish the vehicles of the association or owner from others.
503.9 Effective September 1, 1994, no company, association or owner shall use a unique or special color scheme, logo or insignia on a fleet containing fewer than twenty (20) licensed and operating taxicabs without prior approval of the Commission.
503.10 Each taxicab, except independent taxicabs (see § 505), shall bear on its left rear the name of the taxicab company or association, and on the right rear the taxicab's fleet number. If space permits, the telephone number of the company or association may be displayed on the rear of the vehicle.
503.11 Effective December 1, 1994, each taxicab, except independent taxicabs (see § 505), shall bear on each front door the telephone number of the taxicab company or association with which it is affiliated.
503.12 Each taxicab shall be painted the Commission approved color scheme with the exception of chrome and non-metal trim.
SOURCE: Final Rulemaking published at 37 DCR 3595, 3597 (June 1, 1990); as amended by Final Rulemaking published at 40 DCR 4047 (June 25, 1993); by Final Rulemaking published at 41 DCR 2370 (April 29, 1994); by Final Rulemaking published at 41 DCR
6953 (October 21, 1994); and by Final Rulemaking published 45 DCR 8866 (December 11, 1998).