Annotations are not edits to the underlying text
Highlighting a passage or drawing a rectangle places visible content on a PDF page. Depending on the tool, text beneath an overlay may remain selectable, searchable or extractable. Treat these changes as markup until you have independently verified their effect on the underlying document structure.
Redaction needs removal, not just concealment
A black box can hide sensitive text to the eye while leaving it in the file. Confidential information may also appear in metadata, attachments, previous versions or annotations. Use a purpose-built redaction workflow, inspect the final PDF with text extraction, and follow your organization's approved document handling rules. SuiteOfficeLab's visible overlay controls should not be treated as secure redaction.
Drawn and digital signatures serve different needs
A drawn signature is an image or vector mark on the page. A cryptographic digital signature normally contains certificate information and can provide tamper evidence. Whether an electronic signature is accepted depends on the organization, document and applicable rules. For any important contract, verify the recipient's requirements rather than relying on appearance alone.
Review exports before sharing
Place markup and signatures on the correct page, save a new copy, and reopen it. Check scale, page count and text readability. Retain the source PDF separately in case a recipient requests a clean version.