G325A signature and native alphabet

[Snicks 0]

Hello I am currently in the early stages of getting my i129f packet ready and had a question regarding the G325A form for my fiancé. 

He is from Serbia and always signs his name in Cyrillic. Would he sign in Cyrillic or write out his name in Roman alphabet?

I know they have the space under for writing it in native language but was wondering how he signs it. 

They use both roman and Cyrillic alphabet in Serbia but in Roman alphabet his name has accents as well (š,ć).

What would be the correct way to sign it and would he write the native name in Cyrillic or just with the accents?

any help would be greatly appreciated 

[KULtoATL 1,551]

It's wet sign i.e. print and sign with black ink. His usual signature is fine.

[Snicks 0]

Thank you. 

So for the space below that says to write in native language I'm guessing he could write it in Cyrillic or Roman alphabet since they use both?