California Code, Revenue and Taxation Code - RTC § 25108

(a) For corporations whose income is subject to the provisions of Section 25101 or 25101.15, the net operating loss determined in accordance with Section 172 of the Internal Revenue Code for a particular taxable year shall be the corporation's “net loss for state purposes” as defined in subdivision (c).

(b) The net operating loss deduction allowed by Sections 24416, 24416.1, and 24416.2, for a taxable year shall be deducted from “net income for state purposes” (as defined in subdivision (c)) for that taxable year.

(c) “Net income (loss) for state purposes” means the sum of the net income or loss of that corporation apportionable to this state and the income or loss allocable to this state as nonbusiness income, as provided by Chapter 17 (commencing with Section 25101).