D.C. Mun. Regs. tit. 11-I, § 559
559.1 A building in the D-6 zone is subject to the use regulations in Subtitle I, Chapter 3 and may generate or receive credits pursuant to Subtitle I, Chapters 8 and 9.
559.2 A building in the D-6 zone fronting on a designated primary or secondary street shall be subject to the use regulations in Subtitle I § 601.
SOURCE: Final Rulemaking published at 63 DCR 2447, 3041 (March 4, 2016 – Part 2).