Enforcement Rules for the Act Governing Relations between Peoples of the Taiwan Area and the Mainland Area Article 57

The place of the household registration as referred to in Article 42 of the Act shall mean the place of the household registration of the party concerned; the area of the household registration as referred to in Articles 55 through 57 and Article 59 of the Act shall mean the Taiwan Area or the Mainland Area, depending on the place of the household registration.
中文原文 臺灣地區與大陸地區人民關係條例施行細則第57條
本條例第四十二條所稱戶籍地,指當事人之戶籍所在地;第五十五條至第五十七條及第五十九條所稱設籍地區,指設有戶籍之臺灣地區或大陸地區。

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