Covering text with a coloured box can leave the original information recoverable. Redaction needs a workflow that removes the selected content.
Find every occurrence
Review the full document for names, reference numbers, signatures and repeated identifiers. Check headers, footers, attachments and scanned pages. A visible page is only one place a PDF can store information; no single rectangle should be treated as a full document audit.
Use the dedicated redaction tool
Select the areas to remove in Redact PDF and use its redaction export. An annotation or a white text background is not equivalent. Choose the supported mode and inspect its limitations, particularly when image regions or overlapping objects are involved.
Test the result
Reopen the exported file, search for the removed terms and attempt to select or copy text in the redacted area. Inspect all pages visually at a useful zoom. For highly sensitive documents, have a knowledgeable reviewer check metadata and non-page content as well.
Share only the reviewed copy
Use a filename that identifies the final redacted version. Keep the unredacted original in an appropriately restricted location. Do not accidentally attach both versions when sending the document.