Name Act Article 4

The ethnic name or Han Chinese name of a Taiwan indigenous person may be registered in the indigenous script together with the name in Chinese characters; the ethnic name or Han Chinese name of a member of another ethnic minority may be registered in Romanized form together with the name in Chinese characters. Neither is subject to the restriction in Paragraph 1 of Article 1.When taking a Chinese-language name during the naturalization process, a foreign national or a stateless person may have his/her original foreign name registered in Romanized form alongside the name in Chinese characters and is not subject to the restriction in Paragraph 1 of Article 1.
中文原文 姓名條例第4條
臺灣原住民族之中文傳統姓名或漢人姓名,均得以傳統姓名之原住民族文字並列登記;其他少數民族之中文傳統姓名或漢人姓名,均得以傳統姓名之羅馬拼音並列登記。
不受第一條第一項規定之限制。
外國人、無國籍人於歸化我國取用中文姓名時,得以原有外文姓名之羅馬拼音並列登記,不受第一條第一項規定之限制。

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