Cal. Rev. & Tax. Code § 24406.6

For purposes of Section 24373.5, and Sections 24404 to 24406.5, inclusive, net earnings shall not be reduced by amounts paid during the year as dividends on capital stock or other proprietary capital interests of the organization to the extent that the articles of incorporation, bylaws of the organization, or other contract with patrons provide that those dividends are in addition to amounts otherwise payable to patrons that are derived from business done for or with patrons during the taxable year.