The Organic Act for the Regional National Taxation Bureaus, Ministry of Finance Article 4

Each regional national taxation bureau shall have one (1) chief secretary of a rank equivalent to senior appointment at the grade of ten (10).
中文原文 財政部各地區國稅局組織通則第4條
各地區國稅局置主任秘書,職務列簡任第十職等。

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