Each utility shall determine currently the costs which are applicable to the steam plant accounts and in the case of costs involving allocations, the amount which is applicable to other accounts, such as operating expenses, taxes, retirement work in progress, other balance sheet accounts, and income or surplus accounts; the intent of this provision being that such costs shall be allocated to the accounts to which they are applicable when they are incurred.
N.Y. Comp. Codes R. & Regs. Tit. 16 § 461.15