(a) This account must include the amortization of unamortized net premium on outstanding long-term debt. Amounts credited to this account must be charged concurrently to account 225, Unamortized premium on long-term debt (§ 367.2250).

(b) This account must be kept or supported so as to show the premium on each class and series of long-term debt.

(c) This account must include the following items:

(1) Loss relating to investments in securities written-off or written-down.

(2) Loss on sale of investments.

(3) Loss on reacquisition, resale or retirement of service company's debt securities.

(4) Preliminary survey and investigation expenses related to abandoned projects, when not written-off to the appropriate operating expense account.