A public body sends a redacted report to a journalist. The names in the text are properly removed. The document properties name the author, and the file path names the folder the document lived in: the case officer's surname and the matter name.
The redaction did not fail. Only the page was examined.
What is in the file without being on the page
A PDF carries a set of fields you only see if you go looking:
- Author and organisation. Usually picked up automatically from the settings of whatever created the document.
- Title, subject and keywords. Frequently still the working title from an earlier draft.
- Creation and modification dates. Timestamps included.
- Producing software. Which application, which version.
- The file path. Some export routes carry the full path of the source file.
- XMP fields. A broader set applications use between themselves, capable of holding a great deal, including editing history.
The file path is the underrated one. Something like C:/Users/j.dewilde/Cases/Merger-Northside/draft-v4.docx contains a username, a matter name and a version, none of which appeared on the page.
What comes across from the source
Beyond the standard fields, it depends where the document came from.
From Word. Margin comments and tracked changes can survive the export, depending on settings. Exporting a draft carrying three colleagues' commentary without accepting or removing it first shares that commentary. See also what "save as PDF" does not remove.
From a system. Exports from a case or matter management system sometimes carry internal references: case numbers, user ids, the template name.
From a scanner. Device name, sometimes a device serial, and the settings used.
Why redaction does not reach this
The part that surprises people, and it is entirely logical once stated.
Redaction operates on page content: this passage must go, so that text is removed. Document properties sit wholly outside that. They are not part of the page, so a tool that edits the page does not touch them.
Which means you can redact a document perfectly according to every rule in why a black box over text is not redaction and still ship the drafter's name with it.
Removing metadata is a separate action, with a separate button, in virtually every tool.
Why AI tools read this too
When parsing an uploaded file, services generally take more than the visible text. Exactly what gets included varies by provider and is rarely documented.
The safe assumption is therefore: what is in the file goes to the service. Not because anything malfunctions, but because you sent the file rather than the page.
That is also the practical argument for checking metadata before an upload and not only before an external send. An internal upload to a chatbot is an external transmission.
What to do before sharing
- Open document properties. In any PDF reader, under file or document properties. Look at author, title, and whether a path is present.
- Run a hidden-information inspection. Most PDF tools have a function that finds metadata, embedded files, comments and hidden layers.
- Remove what has no business being there. Author and organisation rarely serve a purpose in a shared document.
- Check again after editing. Some tools write their own name and a fresh modification date back the moment you save.
Four steps, a minute in total. That is the ratio at stake here: a minute of checking against a piece of data you never meant to share and cannot retrieve afterwards.
