This system of accounts is designed for use by steam utilities. If the utility, in addition to its steam operations, operates other departments, it shall keep such accounts for the other department as may be prescribed by this commission, and in the absence of prescribed accounts, it shall keep such accounts as are proper or necessary to reflect the results of operating each such other department. It is not intended that proprietary and similar accounts which apply to the utility as a whole shall be departmentalized. (See also section 461.2[g] of this Part.)
N.Y. Comp. Codes R. & Regs. Tit. 16 § 461.13