Redaction is available in the Advanced version of Power PDF, via the Security ribbon.
Redaction is the blacking out of sensitive text or pictures from a PDF file. Remove elements (also accessed via the Security ribbon) serves to remove hidden or background information.
Due to possible legal consequences of exposing such information, it is common to redact document contents before public release. The PDF format is complex, and may contain more information than is immediately visible. Users can leak sensitive information unintentionally.
A key concept is that Deletion is not equal to Redaction. The information you delete from a PDF with the Delete command is not actually cleared from the document permanently and can almost always be recovered.
Highlights of Redaction
Redaction lets users sanitize PDF documents they want to release. It is usually a two-step process: first you select and mark items to be removed, then after re-checking you apply the redaction. See the appearance of marked and redacted text under Redacting Content. With Redaction tools, you can:
Select and remove text, vector graphics, bitmap images, or multi-object areas.
Search and remove specific text within the current document.
Remove all references of certain content from the current document.
Show redacted areas as unreadable highlights, optionally overlaid with a Secrecy Coding or a predefined custom text.
Highlights of Document Inspection (Removing Document Elements)
Remove all comments from a document.
Remove document properties and other metadata.
Remove links, destinations, attachments etc.
Remove embedded indexes (under 'Remove embedded non-display data') that may still contain redacted text strings.
Redaction and document flattening
Documents can also be prepared for public distribution by flattening the PDF file. This can remove layers, annotations or mark-ups of specified types from the document, or transforms them into document objects, so they no longer appear in the Comments panel. You can select 'Redaction' as a choice for flattening. In this case:
Black rectangles cover redacted text; these can be selected and moved, but the underlying content cannot be seen or searched. In other words, redaction remains intact.
Black rectangles cover text marked for redaction, but it is not actually redacted; these can be selected and moved, but then the underlying text or object becomes visible, so no redaction has been performed.
Redaction by searching
Redaction can be combined with the searching function. The following are available:
Search and Redact: Found items are marked for redaction, as described in Searching and Redacting Text. Choose this from the Document menu.
Scan and Markup: Found items are highlighted, struck out, underlined or marked for redaction, according to your choice. Choose this in the Scan menu; see Creating PDF Files from a Scanner.
Note
Packages and Portfolios can be redacted by searching. Packages containing only PDF files can be redacted in this way, but packages containing package files may not be correctly redacted. When redaction is applied to a portfolio, only the PDF files in the portfolio will be redacted. In general, it is safer to unpack files before redacting them, because this enables redaction by selection and the results can be examined more easily.