A claim shall be deposited in the claiming box at least 10 minutes before the time fixed for the race to begin. An official of the association may not give information as to the filing of claims therein until after the race has been run. A claim shall be passed upon by the stewards or their designated representative. When a claim has been filed it is irrevocable and at the risk of the claimant.
58 Pa. Code § 163.261
This section cited in 58 Pa. Code § 163.251 (relating to general provisions).