California Code, Revenue and Taxation Code - RTC § 23457

(a) Section 57(a)(5) of the Internal Revenue Code, relating to tax-exempt interest, shall not be applicable.

(b) Section 57(a)(6) of the Internal Revenue Code, relating to accelerated depreciation or amortization on certain property placed in service before January 1, 1987, is modified to read: With respect to each property as described in Section 1250(c) of the Internal Revenue Code as that provision read on April 1, 1970, the amount by which the deduction allowable for the taxable year for exhaustion, wear, tear, obsolescence, or amortization exceeds the depreciation deduction that would have been allowable for the taxable year, had the taxpayer depreciated the property under the straight line method for each taxable year of its useful life (determined without regard to Section 24354.2 or 24381) for which the taxpayer has held the property.