If a paper is notarized, a notary has officially signed and stamped it, so the law treats the signature as real. People notarize contracts, copies of documents, and sworn statements — not homework or a birthday card. American English writes notarized; British English often writes notarised. You notarize a document, not a person. Though actually, what happens in the room is often simple: you show your ID, you sign while the notary watches, and they add a seal. The seal is the point. Without it, you only have a signature.

經過公證的、已公證（台灣說「公證」，文件拿到公證人事務所辦理）