What is Certificate of Citizenship?
Certificate of Citizenship meaning A document issued by DHS as proof that the person is a U.S. citizen by birth (when born abroad) or derivation (not from naturalization). The Child Citizenship Act of 2001 gives U.S. citizenship automatically to certain foreign-born children of U.S. citizens. These children can apply for certificates of citizenship.
reference: U.S. Visas – Glossary