When this helps
You want to know whether an earlier draft is still inside a PDF. Some editors append a new file state when saving; others rewrite the PDF. Only retained states can be inspected. A file with one visible saved version may have been edited many times before it reached you.
Try it in the checker
Select a PDF and let the additional checks finish. Summary shows Saved versions. Click it, or choose Everything and select Saved versions from Explore this PDF. Read any incomplete-history warning before using the count.
Each entry identifies a retained version in save order. Download this version saves the original file prefix through that version’s boundary. Open it separately to review its pages and metadata. This does not edit your source file. Earlier copies can contain information removed from the current pages.
Read the result in context
The public sample PDF contains six retained states. It deliberately changes document properties over several saves, then adds an unreferenced XMP packet. Comparing a downloaded earlier version with the current file demonstrates why old fields must not be presented as current metadata.
The count describes file states, not a list of human actions. One save can change many pages, and an ordinary signing operation can also append a state. A retained version does not automatically mean something suspicious happened.
What this cannot establish
The history reader follows cross-reference links rather than treating every end-of-file string as a save. Damaged links, recovery and parsing limits can leave an incomplete history. It does not recover edits that were overwritten or never included. Historical objects inside compressed streams may need a second parser. A saved version can reveal old content, but it is not a guaranteed recovery method for redacted text.