Enforcement rules concerning the implementation of industrial group act. Article 18

The number of directors of industrial board of trade should be multiple of three and odd number, moreover, the number of directors should not be less than nine.
中文原文 工業團體法施行細則第18條
工業同業公會理事名額應為三人之倍數及奇數,並不得少於九人。

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