Excellent and comprehensive document describes how to remove potentially embarrassing metadata from Word and PDF documents.
Redaction FAQs:
Q: What is redaction?
A: Redaction, also known as sanitizing, is a form of editing where sensitive information is removed from a document.
Q: How is redaction performed?
A: Redaction takes a finished document and blocks sensitive content in-place. The “flow” of the document is not changed; rather, sensitive information can be covered in black ink, or covered with white paper.
Q: Can documents be redacted electronically?
A: Yes, if it’s done correctly. Done wrong, the data that is “covered” is still there and can be discovered by people who know how to look. Read the following article from the NSA on redacting documents safely.
Redacting with Confidence: How to Safely Publish Sanitized Reports Converted from Word to PDF
Q: Can PDF documents be redacted?
A: Yes, as long as they are not locked (which can prevent editing). Adobe Acrobat Professional 8.0 has a built-in redaction tool that makes redaction easy to use and highly effective. Acrobat has a redaction toolbar that permits the user to select text and graphics to be redacted. Selected candidates are highlighted in red until redaction is applied.
Q: Are there any disadvantages to redaction?
A: If redaction is done improperly, it may be possible to discern what has been redacted. When individual words are redacted, the length of the redacted word is clearly visible. Sometimes it is smart to redact surrounding words in order to obscure the words that are actually sensitive.
Peter H. Gregory 
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