Unofficial translation: [ROC] Nationals and foreign nationals of 26[*] countries/regions – Argentina, Australia, Austria, Belgium, Brazil, Canada, Colombia, Denmark, Finland, France, Germany, Iceland, Ireland, Luxemburg, Malta, Mexico (some regions), the Netherlands, New Zealand, Norway, Portugal, South Africa, Spain, Sweden, the UK (some regions), the US, and Uruguay – in which same sex marriage is legal may engage in registration of a same sex marriage.
*It seems to be 26 including Taiwan.
Unofficial translation: Regarding 2 [ROC] nationals or a national and a foreign national from a country where SSM is legal who were married before 2019-05-24 in a country where SSM is legal, to engage in registration of SSM they can rely on their authenticated [經驗證] marriage documents, the dates of coming into effect of which are in accordance with the provisions of Art. 24 of the 司法院釋字第七四八號解釋施行法 [implementation law of JY Interpretation #748 i.e. the SSM law] and Art. 46 and 62 of the Act Governing the Choice of Law in Civil Matters Involving Foreign Elements, with the date on which SSM registration is conducted at the Household Registration Office prevailing.