If a horse is sold by private sale, or at public auction, the written acknowledgement of both parties is necessary to prove the fact that he was sold with his engagements, but when a horse is sold or claimed out of a claiming race, the horse's engagements are included unless the advertised conditions of the race state specifically to the contrary. A sale, under any circumstances, to a person ruled off, or to a disqualified person, shall have the effect of a declaration of forfeit as if made by the vendor on the date of sale.
Ill. Admin. Code tit. 11, § 1413.270