Basic Code Governing Central Administrative Agencies Organizations Article 6

The names of administrative agencies shall be defined as follows:1. Yuan: First-level agency.2. Ministry: Second-level agency.3. Council, Commission: Second-level agency or independent agency.4. Administration, Bureau: Third-level agency.5. Branch: Fourth-level agency.An agency may also be named otherwise due to special nature of its functions.
中文原文 中央行政機關組織基準法第6條
行政機關名稱定名如下:
一、院:一級機關用之。
二、部:二級機關用之。
三、委員會:二級機關或獨立機關用之。
四、署、局:三級機關用之。
五、分署、分局:四級機關用之。
機關因性質特殊,得另定名稱。

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