Regulations Governing Securities Investment and Futures Trading in Taiwan by Mainland Area Investors Article 31

Only after overseas depositary receipts have been redeemed may an Institutional Investor, itself or through a depository institution, within the scope of the original number of shares redeemed, purchase the original securities from the Taiwan market or deliver to the custodian institution original securities it already holds, for the depositary institution subsequently to reissue overseas depositary receipts based thereupon.Overseas depositary receipts reissued pursuant to the preceding paragraph are limited to those for which it has been expressly stipulated in the deposit contract and custody contract that after redemption the overseas depositary receipts may be reissued.
中文原文 大陸地區投資人來臺從事證券投資及期貨交易管理辦法第31條
海外存託憑證經兌回後,機構投資人始得自行或委託存託機構在原兌回股數範圍內自臺灣地區市場買入原有價證券或將其已持有之原有價證券交付保管機構後,由存託機構據以再發行海外存託憑證。
依前項規定再發行海外存託憑證,以存託契約及保管契約已載明海外存託憑證經兌回後得再發行者為限。

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