7 Pa. Code § 305.134
No horse shall be permitted to start in a race unless approval is given by the Starter. The Starter shall maintain a Starter’s List of all horses which are ineligible to be entered in any race because of poor or inconsistent behavior or performance in the starting gate. The horse shall be refused entry until it has demonstrated to the Starter that it has been satisfactorily schooled in the gate and can be removed from the Starter’s List. Schooling shall be under the direct supervision of the Starter.