Section 24349(f) - ***** Depreciation in Special Cases(a) Depreciation of Patents or Copyrights. The cost or other basis of a patent or copyright shall be depreciated over its remaining useful life. Its cost to the patentee includes the various government fees, cost of drawings, models, attorney's fees, and similar expenditures. If a patent or copyright becomes valueless in any year before its expiration the unrecovered cost or other basis may be deducted in that year.
(b) Depreciation in Case of Farmers. A reasonable allowance for depreciation may be claimed on farm buildings, farm machinery, and other physical property but not including land. Livestock acquired for work, breeding, or dairy purposes may be depreciated unless included in an inventory used to determine profits in accordance with Section 24271 and the regulations thereunder. Such depreciation should be determined with reference to the cost or other basis, salvage value, and the estimated useful life of the livestock. See also Section 24343 and the regulations thereunder relating to trade or business expenses, Section 24347 and the regulations thereunder relating to losses of farmers and Section 24369 and the regulations thereunder relating to soil or water conservation expenditures. __________
***** This regulation is substantially the same as Section 26 CFR 1.167(a)-6.
Cal. Code Regs. Tit. 18, § 24349(f)