(a) This section contains an outline of the procedures used in the assignment of Telecommunications Plant in Service-Account 2001 to categories and the apportionment of the cost assigned to each category among the operations.(b) The treatment of rental plant is outlined in §§ 36.2(c) through 36.2(e) . If the amount of such plant is substantial, the cost may be determined by using the general procedures set forth for the assignment of the various kinds of property to categories.(c) The amount of depreciation deductible from the book cost or "value" is apportioned among the operations in proportion to the separation of the cost of the related plant accounts.