California Code, Business and Professions Code - BPC § 19611.5

(a) In addition to the amounts otherwise deducted pursuant to this chapter, every association other than a fair that conducts a thoroughbred race meeting may deduct from the total amount handled in daily double, quinella, exacta, and other multiple wagering pools approved by the board up to 3 percent thereof to be distributed 50 percent as commissions and 50 percent as purses.  From the amount distributed as purses, a sum equal to 0.07 percent of the total handle shall be held by the association to be deposited with the official registering agency pursuant to subdivision (a) of Section 19617.2, and shall thereafter be distributed in accordance with subdivisions (b), (c), and (d) of Section 19617.2.

(b) At least 30 days prior to the commencement of its meeting, the association shall file with the board a statement of the additional deduction to be made pursuant to subdivision (a).  Except with the consent of the board, the amount of the deduction shall not be changed during the course of the meeting.