How to Remove Hidden Unmarked Set By Comments in PDF Redactions
Question details
The user needs to prevent hidden sticky notes labeled "Unmarked set by" from appearing on redacted PDFs when opened in third-party viewers, without deleting essential bookmarks.
- Product
- Adobe Acrobat
- Device & OS
- macOS
- Scenario
- Redacting sensitive text in a PDF document and sharing it with users who may open the file in non-Adobe PDF viewers like macOS Preview.
- Observed behavior
- Redaction tools leave behind hidden metadata that renders as visible sticky notes labeled "Unmarked set by" in third-party viewers. Using the full "Sanitize Document" feature removes the notes but undesirably deletes all document bookmarks.
Before removing hidden information or sanitizing your redacted PDF, ensure you have saved a backup copy of the original, unredacted file to prevent accidental loss of important data or bookmarks.
Selectively Remove Hidden Information to Preserve Bookmarks
Instead of using the aggressive "Sanitize Document" feature, use the "Remove Hidden Information" tool to delete comments while selectively keeping your bookmarks intact.
The "Sanitize Document" function is designed to strip all metadata, including bookmarks, links, and hidden layers. By choosing to manually inspect and remove hidden information, you can target the problematic redaction metadata without breaking document navigation.
Make sure all your redactions are applied and finalized in your PDF editor so that the sensitive text is permanently burned out of the document.
Navigate to "Tools" > "Protect" and select "Remove Hidden Information" instead of clicking "Sanitize Document".
Allow the tool to analyze the document. It will display a list of all hidden text, metadata, comments, and deleted content found within the PDF.
Review the results pane. Uncheck the box next to "Bookmarks" to ensure they are preserved, but make sure "Comments and Markups" remains checked to delete the "Unmarked set by" notes.
Click the "Remove" button to clear the selected metadata, then save the document as a new PDF file and test it in macOS Preview.
Flatten the PDF to Remove Interactive Comments
Flattening the PDF merges all annotations, comments, and redactions into the base document layer, preventing third-party viewers from misinterpreting hidden metadata as sticky notes.
Redact and Secure PDFs Reliably with WPS Office
Avoid hidden metadata and cross-viewer compatibility issues by using WPS Office. WPS PDF provides clean redaction and document flattening tools to ensure your privacy is protected without leaving ghost comments or breaking bookmarks.
- 1. Open your PDF in WPS Office: Launch WPS Office and open the PDF document that contains sensitive information you wish to hide.
- 2. Access the Redact tool: Navigate to the "Protect" tab in the top ribbon and select the "Redact" feature.
- 3. Apply your redactions: Highlight the sensitive text or draw a box over the areas you want to remove, then click "Apply Redactions" to permanently erase the data.
- 4. Save a clean copy: Use the "Export to PDF" or internal print functionality to generate a secure, flattened copy that is fully compatible with third-party viewers like macOS Preview.
Frequently Asked Questions
Why do "Unmarked set by" comments appear only in macOS Preview?
Different PDF viewers interpret PDF metadata and annotation layers differently. Adobe Acrobat hides redaction metadata natively, but default system viewers like macOS Preview may mistakenly render these hidden properties as visible sticky notes.
Does the Sanitize Document tool always remove bookmarks?
Yes, the standard "Sanitize Document" feature aggressively removes all metadata, bookmarks, links, and hidden data to ensure total security. To keep bookmarks, you must use the "Remove Hidden Information" tool selectively instead.
Can I remove sticky notes without flattening the PDF?
Yes. By using the "Remove Hidden Information" tool and specifically checking "Comments and Markups" while unchecking "Bookmarks", you can delete the ghost sticky notes while keeping your document's navigation and text layers intact.
Will converting the PDF to an image remove the hidden comments?
Yes, converting the PDF to an image format (like JPG) and then back to a PDF will completely destroy all metadata and hidden text layers, preventing hidden comments. However, this also makes the document unsearchable and removes all bookmarks.
