Removing the Hidden Data in Your Documents
Written on June 4, 2004 by Robert & Karen Vanderzweerde
Appeared in Greenmaster Magazine
Did you know that when you share a Microsoft Word document with someone, you
may be sending more information than you intend? This may include personal
information, deleted text, revision marks, and locations of files on your
Microsoft, in an attempt to make its software user friendly, faster, and to
enable collaboration, stores hidden data or leaves deleted information in your
document. When you send the document to someone, they can then look up all that
Normally, this not a problem if you share information amongst friends or
people within your organization. It becomes important when you send (or receive)
proposals, legal documents, customer letters, or any information shared with the
public (e.g. a guide published on you web site). There have been cases of
lawsuits initiated based on the data hidden in a shared document.
Here's how to find the hidden information and how you can protect yourself if
you share your document. Most of these apply to Microsoft Word.
Hidden Danger: File Properties
When a document is saved for the first time, Microsoft Word automatically
fills in the title based on the first few words in the document and your name
and company based on the license information that you filled in when you
installed the software.
To see the hidden information, open the File menu and select Properties.
The quick way to protect yourself is to erase the text in the title, name,
and company fields when you use File | Properties. However, it's easy to forget
to do this. To further protect yourself, open the Tools menu, select Options,
click on the Save tab, and ensure that "Prompt for document
properties" is checked. Then, whenever you save a document for the first
time, you get to see and change the properties.
In the XP version of Microsoft Word, you can open the Tools menu, select
Options, click on the Security tab, and ensure that "Remove personal
information from this file on save" is checked.
Hidden Danger: Deleted Text
Text that you delete from a document is not actually deleted. It is just
marked as deleted but the text remains in the file. Mircrosoft does this to
enable the very useful Undo command (i.e. you can't undelete text if the text is
physically not there). When you save the document, the deleted text is saved too
if the "allow fast saves" option is on.
To see the deleted text, open the document as a text document.
The only way to physically remove deleted text is when a document is saved
without using the "allow fast saves" option. When saving a document,
select Save As, and then click on Save to bypass the "fast save". You
can turn off "fast saves" permanently by opening the Tools menu,
selecting Options, clicking the Save tab, and ensuring that "Allow fast
saves" is unchecked.
Hidden Danger: Tracked Changes, Revisions, and Comments
Whenever two or more people work on a document, it is nice to be able to turn
on the "Track changes while editing" feature or to insert revision
marks or comments. The recipient of the document, especially if it has been
modified many times, can easily focus on the changes, revisions, or comments
rather than re-reading the entire document.
To see any hidden changes that have been tracked, open the Tools menu, select
Track Changes, select Highlight Changes, and ensure that "Highlight changes
on screen" is checked.
There is only one way to remove tracked changes and that is to accept or
reject them and create a "clean" version of a document. Do this by
opening the Tools menu, selecting Track Changes, clicking on Accept or Reject
Changes, and making sure to either accept or reject each change.
To see hidden comments, open the View menu and select Comments. Each comment
must be deleted individually to remove them.
For any other hidden text, you can view it by opening the Tools menu,
selecting Options, clicking on the View tab, and checking the "Hidden
text" under "Formating marks". The hidden text must be deleted
manually (just a you delete any other text).
Hidden Danger: Version Control
Sometimes, when it takes a long time to create a large, complex document or
to make major changes to a document, it's nice to save an older version for
To see previous document versions, open the File menu and select Versions. If
there are any saved older versions, you can open and read them.
To delete any unwanted versions, open the File menu, select Versions,
highlight the version to deleted and click on the Delete button.
The Safest Publishing Strategies
The safest way to share or publish a document is not to share the document at
all. First, you publish it and then you shared the published version.
There are two main ways to do this.
If you publish a lot of materials, the most useful method is to use the
Portable Document Format (PDF) made popular by Adobe Acrobat. Many documents
sent out by large firms or downloadable from web sites are published in this
manner. As the publisher, you need to buy the Adobe Acrobat software (about
$299US for the standard version). As the reader, you need to install the free
Adobe Acrobat Reader. Both are available online at www.adobe.com.
If you publish occasionally, then you should take all of the protective
measures listed in this article. If your document is text only (i.e. no pictures
or graphics in it), you can also publish it as a web page. The web version of
the document does not support hidden text. To do this in Microsoft Word, open
the File menu and select Save as Web Page.
Of course, if you're really paranoid, you can always print the document and
either fax or mail it. However, this seems so backward in our age of electronics
Remember to remove the hidden data in your documents. Practice safe document