Neither my wife nor son were required to sign their naturalization certificates when they took their oaths. Now we want to apply for US passports for them and there is some question about how to sign the name. The general advice is to sign with the full name as printed on the certificate but its also advised that it has to match the signature on the photograph which in this case not the full name for either of them. We are planning on using the same signature as on the photo unless someone talks us out of it. What have others done?