Author Information in Documents, PDFs, and Office Files

When handling documents for whistleblowing, do not look only at the body text.

PDFs, Word, Excel, PowerPoint, and imaged materials may retain author information, edit history, comments, templates, file paths, and distribution identifiers.

Even if you remove a name from the body text, anonymity breaks if the author's name remains inside the file.

This article organizes author information in documents, PDFs, and Office files that requires particular caution in whistleblowing.

What Is Author Information?

Author information is information attached to a file, such as the author, company name, editor, creation software, and creation date/time.

Office documents and PDFs may retain information that is not visible from the document's appearance.

These may remain as properties or metadata even if they do not appear on the screen when the file is opened.

Cautions for Office Files

Word, Excel, and PowerPoint easily retain change history and comments.

Especially in internal documents, reviewers, department names, revision history, hidden sheets, and embedded objects become clues.

Sending Office files outside as-is is dangerous.

Create a publication copy and check for unnecessary history and comments. However, in situations where evidentiary value is needed, preserve the original before processing.

Cautions for PDFs

PDFs look safe, but information remains inside them.

They may include author, creation software, annotations, forms, embedded text, text under redaction, and attached files.

Simply converting to PDF does not make a file safe.

Check redaction, annotations, properties, and embedded information.

Be Careful With Redaction Failures

In whistleblowing materials, names or numbers may be redacted.

However, if you only place a black rectangle on top, the text underneath may remain. It may be possible to copy text from the PDF, search for it, or see it when layers are removed.

Do not judge redaction by appearance alone.

Open the publication file in another app, and check copying, search, and properties.

Limits of Screenshots

Some people think making a screenshot of a document makes it safe.

Screenshots may reduce some metadata, but they are not a universal solution. Notifications, account names, times, OS UI, browser tabs, and filenames may appear on the screen. Image files may also retain creation time or device information.

Converting to a screenshot is not a process that removes all problems from the original.

It requires separate checking as a publication image.

Separate Checking From Preservation

In whistleblowing, thinking only about removing metadata is dangerous.

The evidentiary value of the original may matter. Information about when a material was created, who created it, and its authenticity may be needed.

What to remove and what to keep changes depending on the purpose.

Providing information to a news organization, consulting a lawyer, and public posting require different judgments.

Do Not Judge by Tools Alone

Metadata checking tools are useful.

ExifTool is a representative tool used to check metadata in many file formats.

URL : https://exiftool.org/

However, information visible to tools is not the only risk. Internal terminology in the body text, document numbers, distribution scope, phrasing habits, and the small number of people who could obtain the file also narrow candidates.

Follow the Recipient's Procedure

It is also important not to over-process whistleblowing materials by your own judgment.

News organizations, lawyers, support groups, and reporting desks may each have procedures for receiving materials and policies for evidence preservation. Before submission, check what format to send, whether the original is needed, and whether an anonymized copy is acceptable.

Safe document handling changes depending on the purpose and destination.

Do not decide by yourself that "deleting makes it safe." Check both the necessary evidentiary value and anonymity.

If judgment is difficult, confirm a safe way to consult the recipient before submission.

Document handling is work that deals with anonymity and evidentiary value at the same time.

If only one side is prioritized, risks that cannot be explained later remain.

Summary

Documents, PDFs, and Office files may retain author information, edit history, comments, file paths, annotations, and hidden data.

Even if you remove a name from the body text, anonymity breaks if a real name or organization name remains inside the file.

In whistleblowing, separate originals, checking copies, submission copies, and publication copies. For materials where evidentiary value is needed, do not process them carelessly; check with a specialist or recipient.

Metadata checking tools are useful, but content correlation and distribution-scope correlation also need to be checked at the same time.

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