In the case a Taiwan ROC citizen married a US citizen, before the marriage certificate is translated, you'll need to come up with a Chinese name for the spouse.
In Taiwan, there is related regulation for foreigner's name translation. They actually allow the translation to have as many Chinese characters as needed. This is to respect one's heritage and culture background.
However, Taiwan ROC's ID card and household registry system allow only 6 characters. In addition, for practical matters, such Taiwan bank accounts, credit cards, and many other documents, it's better off to use just 3 characters - one character for your last name, and two characters for the first name.
As for the process, you first need to file name declaration form with TECO office. They will review the translation and approve it. With the approved translation of name, then you can have your marriage certificate translated and notarized. Then you can have your marriage certificate go through TECO document verification process.
美國矽谷灣區翻譯公證
http://sites.google.com/site/ameritrantranslationservices
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