You cannot add a comment to your signature. However, a standard legal phrase—such as “Read and approved”—can be requested by the signing platform.

A document for signing is only presented once agreement or consensus has been reached. This is also the case with paper-based agreements or contracts: a document is created to formalize the agreed terms.

• At that point, the content and the signatories are already known.
• A signatory cannot add anything to the document. It is a PDF/A file, and any modification would invalidate its legal status.
• This means the original content cannot be overwritten.
• The signature is added as an extra layer, which is permitted by the PDF/A format.