I am filling out my N400 Online application and got to the "Spouse" section. my wife has had a "FNU" on her VISA and Green card since she has been in this country. the N400 asks for the Spouse Name as show in her Birth certificate - which is in the correct format on the Birth Certificate However they also ask for the GC number which has her listed as FNU and her whole name in the SURNAME field. There is a question there that asks "Has your Spouse ever used a different name" ? should I enter FNU there? Advice is appreciated!