Metadata is data within or about the data. Often, it is not seen when viewing the onscreen or printed document. However, simple tools and a curious eye can bring undesirable and even confidential information to light.
For instance, by simply leaving the “Track Changes” feature turned on in Microsoft Word (which can be very useful in the draft process within a group editing situation) the changes – including text that has been deleted and replaced – are saved as part of the document.
When a document with metadata is sent to a party outside of the firm, all of the embedded metadata is vulnerable and could divulge confidential information not intended for others.