Aircraft Flight Operation Regulations Article 23

No one may perform power-back operations unless the operator has established procedures for such operations and has been approved by CAA.
中文原文 航空器飛航作業管理規則第23條
航空器使用人非經訂定航空器動力後退程序並報請民航局核准者,不得進行動力後退作業。

English translation for reference only; the Chinese text prevails. Not legal advice.