D.C. Mun. Regs. tit. 3, § 1613
1613.1 Each person eligible to vote in a primary election for U.S. Representative may cast a ballot for no more than one (1) candidate in the contest.
1613.2 At the time of certification of the primary election results for the office of U.S. Representative, the individual receiving the highest number of votes in each party primary shall be certified the nominee of that party.
SOURCE: Final Rulemaking published at 36 D.C. Reg. 8364, 8371 (December 15, 1989).