Consumer Protection Act Article 54

Where a mass of parties injured out of the same consumer relationship, the court may announce by public a notice, after obtaining the consent of the representative(s) selected by other injured parties in accordance with Article 41 of the Code of Civil Procedure, whereby other injured parties may file a demand for judgment in the same litigation procedure within a time limit, containing the facts, evidences and the declaration of claims in writing. Persons making such filing shall be deemed to have made the selection in accordance with Article 41 of the Code of Civil Procedure.Copies of the filing in writing concerning the same litigation set forth in the preceding paragraph shall be sent to both the plaintiffs and the defendants.The time limit referred to in the first paragraph shall be not less than 10 days. The public notice shall be attached to the bulletin board of the courthouse and shall be published in newspapers with expenses to be paid for by the National Treasury.
中文原文 消費者保護法第54條
因同一消費關係而被害之多數人,依民事訴訟法第四十一條之規定,選定一人或數人起訴請求損害賠償者,法院得徵求原被選定人之同意後公告曉示,其他之被害人得於一定之期間內以書狀表明被害之事實、證據及應受判決事項之聲明、併案請求賠償。
其請求之人,視為已依民事訴訟法第四十一條為選定。
前項併案請求之書狀,應以繕本送達於兩造。
第一項之期間,至少應有十日,公告應黏貼於法院牌示處,並登載新聞紙,其費用由國庫墊付。

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