California Code, Business and Professions Code - BPC § 19408.3

“Stakes race” means a race for which owners of horses entered or engaged for the race contribute to a purse for which money or any other prize may be added, nominations to which close 72 hours or more before starting; or an invitational race or invitational handicap race for which owners do not conribute  1 to the purse, but which is advertised in the regular stakes program.