I have a question: I recently got my US Citizenship and need to apply for a visa for my in-laws visiting me. While filling up the I-134, there is a question "If a United States citizen through naturalization, give certificate of naturalization number" Now, I see my Certificate of Naturalization and see 2 numbers. One is No:XXXXX and other one says CIS Registration No: AXXXXX. WHich one should I put? Please let me know. Thanks HELP!!!