47 CFR 32.3000: Instructions for balance sheet accounts—depreciation and amortization.

(a) Depreciation and amortization subsidiary records. (1) Subsidiary record categories shall be maintained for each class of depreciable telecommunications plant in Account 3100 for which there is a prescribed depreciation rate. (See also § 32.2000(g)(1)(iii).)

(2) Subsidiary records shall be maintained for Accounts 2005, 2682, 2690, 3400 in accordance with § 32.2000(h)(4).

(b) Depreciation and amortization accounts to be maintained by telephone companies, as indicated.

Account title

Depreciation and amortization:

Accumulated depreciation 3100

Accumulated depreciation—Held for future telecommunications use 3200

Accumulated depreciation—Nonoperating 3300

Accumulated depreciation—Tangible 3400