3.6 How to prevent watermark on PDF file from being removed by the PDF editing tool?

Solution: PDF editing tools can remove any element content, including watermark, from PDF files. However, by edit encrypting PDF file, it can avoid malicious editing of the file, such as setting an editing password, so that any user must enter the correct password before editing the PDF file, ensuring that the watermark will not be removed. This is suitable for scenarios where PDF attachments are downloaded with watermark from Confluence, usually edit encrypting them before uploading them.