When my brother got his citizenship that day,he said the local USCIS officer told them the citizenship certificate could not be copied.I read some information in this site that some US citizenship friends apply GC for their parents and they submitted the copy of their citizenship certificate.My question is:
1.Is it true the certificate can not be copied?
2.If not, how can we prove that my brother is a US citizen and my parents are qualified to apply GC now?
Thank you very much for your input.