Editing tips from the NSA

Hiding confidential information with black marks works on printed
copy, but not with electronic documents, the National Security Agency
has warned government officials.

The agency makes the point in a guidance paper on editing
documents for release, published following several embarrassing
incidents in which sensitive data was unintentionally included in
computer documents and exposed. Instead of covering up
digital text with black boxes, it is better to delete any information
you don't want to share, the NSA suggested.

The unintended disclosure of metadata, resulting in high-profile leaks
of secrets, has led to red faces at businesses and government bodies in
the past. In March 2004, a gaffe by The SCO Group revealed which
companies it had considered targeting in its legal campaign against Linux users.

The 13-page paper is called: "Redacting with confidence: How to safely publish sanitized reports converted from Word to PDF."

Download: Redacting with Confidence (PDF)