Enforcement Rules for the Issuance of ROC Visas to Foreign-Passport Holders Article 12

Family members of, and others accompanying, officials of specific inter-governmental organizations and foreign agencies that are based in the ROC may apply for single/multiple-entry resident visas with a duration of no longer than 5 years.The above-mentioned persons, unless possessing official identification cards issued by MOFA, shall apply for ARCs.
中文原文 外國護照簽證條例施行細則第12條
對於駐我國之特定政府間國際組織、外國機構執行公務者及其眷屬、隨從人員,得核發效期不超過五年、單次或多次入境之居留簽證。
前項人員未持有外交部核發之政府間國際組織、外國機構、官員證、職員證或外籍隨從證者,應申請外僑居留證。

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