When you distribute an Office document electronically, the document might contain information that you do not want to share publicly, such as information you’ve designated as “hidden” or information that allows you to collaborate on writing and editing the document with others.

[ Download details: Office 2003/XP Add-in: Remove Hidden Data ]

I am not of the habit of typing things in documents that could cause any issues, but I will sleep more soundly (like I ever have a problem sleeping, thank God) knowing that no one else "hid" anything suspect in a Microsoft^® Word™ document that I forward to a client.