The meaning of all accounting terms used in this article, and the calculation of each amount to be computed under any provision of this article, shall be determined in accordance with the uniform system of accounts for railroad companies or other applicable rules, regulations, or orders of the interstate commerce commission, or other federal regulatory agency having jurisdiction at the time over the accounts of the corporation or, to the extent not so governed, in accordance with sound accounting practice.
N.Y. R.R. Law § 310