Civil Associations Act Article 38

Where a member (member representative) of an occupational association cannot attend the members’ (member representatives’) assembly, he may entrust in writing another member (member representative) to represent him. However, the number of the entrusted attendees may not exceed one-third of the attendees who attend the meeting by themselves.Each member (member representative) may represent only one other.
中文原文 人民團體法第38條
職業團體會員(會員代表)不能親自出席會員(會員代表)大會時,得以書面委託其他會員(會員代表)代理。
但委託出席人數,不得超過該次會議親自出席人數之三分之一。
每一會員(會員代表)以代理一人為限。

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