When an agent modifies a document after it is signed by the one or both of the parties, this is referred to as:

Defacing means intentionally damaging or marking a document to make it illegible or alter its appearance, which is different from making corrections. Defacing is generally done with malicious intent and is never appropriate in real estate transactions.

Notarization involves having a document certified by a notary public to verify the identity of signers and ensure they signed willingly. It's a formal authentication process, not a modification of content after signing.

Amanuensis refers to a person employed to write what another dictates or to copy what has been written by another. It's related to document creation but not to post-signing modifications.