有国内的一些材料，我打算找朋友翻译签名。按照这里http://www.uscis.gov/forms/forms-and-fees/general-tips-assembling-applications-mailing 的解释，我只要附上说明就可以了。
问题是朋友的签名需要找这边的public notary公证吗？还是并不需要？
谢谢了！
The certification format should include the certifier's name, signature, address, and date of certification. A suggested format is:
Certification by Translator
I [typed name], certify that I am fluent (conversant) in the English and ________ languages, and that the above/attached document is an accurate translation of the document attached entitled ______________________________.
Signature_________________________________
Date Typed Name
Address