Cal. Code Regs. tit. 4 § 1439
Each association shall, if a corporation, maintain a current list of stockholders and the number of shares held by each and such list shall be available for inspection by the Board. The association shall immediately inform the Board of any change of corporate officers or directors, or any change in stockholders when such change of the holdings of any individual stockholder exceeds 5% of the outstanding shares of the corporation. The real owner of the stock shall be listed if known. The Board may require the disclosure of the real name of any individual or person who holds over 5% of the outstanding shares of any racing association and may refuse to issue a license to, or suspend the license of, any association which fails to disclose the real name of such shareholders if such information is known to or ascertainable by the association.
Cal. Code Regs. Tit. 4, § 1439