Cal. Rev. & Tax. Code § 23709

(a) For the purposes of this part the term “private foundation” means a domestic or foreign organization defined in the Internal Revenue Code as a private foundation.
(b) For the purposes of this part, if an organization is a private foundation (within the meaning of subdivision (a)) on December 31, 1970, or becomes a private foundation on any subsequent date, such organization shall be treated as a private foundation for all periods after December 31, 1970, or after such subsequent date, unless its status as such is terminated.
(c) For purposes of this part, an organization the status of which as a private foundation is terminated shall be treated as an organization created on the day after the date of such termination, except in the case of a transfer of assets of any private foundation to another private foundation pursuant to any liquidation, merger, redemption, recapitalization, or other adjustment, organization, or reorganization, the transferee shall not be treated as a newly created organization.
(d) For purposes of this part, the term “support” includes (but is not limited to)—
1. (1) Gifts, grants, contributions, or membership fees,
2. (2) Gross receipts from admissions, sales of merchandise, performance of services, or furnishing of facilities in any activity which is not an unrelated trade or business (within the meaning of Section 23734),
3. (3) Net income from unrelated business activities, whether or not such activities are carried on regularly as a trade or business,
4. (4) Gross investment income (as defined in subdivision (e)),
5. (5) Tax revenues levied for the benefit of an organization and either paid to or expended on behalf of such organization, and
6. (6) The value of services or facilities (exclusive of services or facilities generally furnished to the public without charge) furnished by a governmental unit referred to in Section 170(c)(1) of the Internal Revenue Code to an organization without charge.
  Such term does not include any gain from the sale or other disposition of property which would be considered as gain from the sale or exchange of a capital asset, or the value of exemption from any federal, state, or local tax or any similar benefit.
(e) For purposes of this section, the term “gross investment income” means the gross amount of income from interest, dividends, rents, and royalties, but not including any such income to the extent included in computing the tax imposed by Section 23731.