NSA's guide to sanitizing your documents. What we're talking about here is actually removing content from files such as PDF's and Word docs (the two most used for docs). It's called redacting. Obviously items such as images and links might not always be fully extracted when you just delete them, so this is also an interesting look into some of the lesser-known settings in your apps. To quote the guide: "The way to avoid exposure is to ensure that sensitive information is not just visually hidden or made illegible, but is actually removed from the original document. Thus any sensitive information must be removed from the document through deletion. The procedures detailed below discuss some of the ways to maintain formatting during the process."