This auditor works on your PDF in your browser. There is no upload, and we keep no record of which files you approve.
What it records
The auditor writes six properties into the PDF's XMP packet, in the MX namespace the file already uses:
| Property | What it holds |
|---|---|
mx:ApprovalDecision | approved, changes-requested or rejected. |
mx:ApprovedBy | The name of the person who made the decision. |
mx:ApprovedAt | The date and time of the decision, in UTC. |
mx:ApprovalNotes | What was checked, and anything the publisher must change or know. |
mx:ApprovedSha256 | The SHA-256 of the exact bytes that were reviewed. |
mx:ApprovedLength | How many bytes were reviewed. |
The reviewed bytes stay unchanged
A PDF can be extended without rewriting it: new versions of its objects are added at the end, and a reader uses the latest. The auditor adds a new version of the metadata stream, and nothing else is touched. What you reviewed is still there, byte for byte, as the start of the approved file. Anyone can check it: take the first ApprovedLength bytes, hash them, and compare the result with ApprovedSha256. The MX Inspector does that check when you drop an approved PDF on it, and says so when more was added after the decision.
Because the original bytes stay as they were, a document that passed PDF/A or PDF/UA validation keeps those identifications. The new properties are declared in the file's PDF/A extension schema, so a validator reading the approved file finds them described.
What an approval is, and is not
An approval here is a recorded statement: a named person, a decision and a time, tied to the exact bytes they saw. The hash proves which bytes the statement covers. It does not prove who wrote the statement, because nothing in it is cryptographically signed. Treat it as the review record that travels with the file, the evidence a publisher shows when asked who checked a document before it went out.
To change your mind, drop the approved file again and record a new decision. The new decision replaces the old one and covers everything up to that point, the earlier one included.