Name Act Article 2

When applying for household registration, naturalization, or a passport, the applicant must supply a name using Chinese characters found in the Chinese etymological dictionary Ci Yuan, the Chinese encyclopedic dictionary Ci Hai, the Kangxi Dictionary, or the Guoyu Cidian compiled by the Ministry of Education.Characters not found in the above dictionaries may not be used.A Taiwan indigenous person who registers his/her ethnic name under his/her culture and customs may use indigenous scripts.
中文原文 姓名條例第2條
辦理戶籍登記、申請歸化或護照時,應取用中文姓名,並應使用辭源、辭海、康熙等通用字典或教育部編訂之國語辭典中所列有之文字。
姓名文字未使用前項所定通用字典或國語辭典所列有之文字者,不予登記。
臺灣原住民族依其文化慣俗登記傳統姓名者,得使用原住民族文字。

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