Dangerous documents.

• Position: Up front: news, trends & analysis - Public documents created in Microsoft Word not safe

According to the British Broadcasting Corp., the U.K. government recently decided to abandon Microsoft Word for documents that become public and instead use documents created with Adobe Acrobat, which uses the portable data format (PDF).

Why? Because metadata, typically considered helpful, may be too helpful to some. A document created, opened, or saved in Microsoft Word may contain content that the author might not want to share with others when the document is distributed electronically. This metadata may include names and user names of authors, companies, network server, or hard drive where the document was saved, file properties, document revisions, template information, hidden or previously deleted text, and e-mail headers, server, and printer information.

Computer experts say information tends to leak when users are working with a document that has had a number of revisions or several authors. A function in many versions of Microsoft Office programs, including Word, Excel, and PowerPoint, allows data fragments from other versions a user previously deleted or was working on at the same time to be hidden in any document he or she saves.

With the right tools, this hidden data can be extracted easily. U.K. computer researcher Simon...