Subchapter XII. Customer Service Operations. Part A. City Wide Call Center. §§ 1-327.01 – 1-327.02 Part B. Customer Service Operations Unit. §§ 1-327.31 – 1-327.34 Part C. Office of Unified Communications. §§ 1-327.51 – 1-327.57 Part D. D.C. One Card. §§ 1-327.71 – 1-327.73