Cal. Code Regs. tit. 2, § 1093.4 – Expense Accounts.

(a) Production
Supervision, labor and expense
Purchased power
Generation fuel, water and steam
Maintenance--structures and improvements
(b) Transmission
Supervision, labor and expense
Maintenance--structures and improvements
(c) Distribution
Supervision, labor and expense
Maintenance--structures, improvements and equipment
(d) Customer accounts
Supervision, meter reading and other expense
Uncollectible accounts
(e) Administrative and general
Salaries
Franchise requirements
Office supplies and other expenses
Rents and leases
Maintenance--general plant
Property insurance, injuries and damages
Other
Employees' retirement and benefits
(f) Other operating
Depreciation and amortization
Other
Taxes
Expense credits
(g) Non-operating
Interest on long-term debt
Other
Expense credits
Other interest
Expenses of other activities
Expenses applicable to prior years