Subdivisions of any account in this system of accounts may be kept, and upon order of the commission shall be kept. The title of each such subdivision shall clearly indicate the account of which it is a part. When an account is subdivided in the general ledger, an account need not also be raised for the total of the subdivisions. When such subdivisions are carried in subsidiary ledgers, however, the general ledger shall contain the controlling accounts therefor so that a complete general ledger trial balance may be obtained.
N.Y. Comp. Codes R. & Regs. Tit. 16 § 196.4