This article is an excerpt from John Walkenbach's Favorite Excel 2007 Tips & Tricks by John Walkenbach. A.k.a. Mr. Spreadsheet, John is arguably the foremost authority on Excel. His forty-plus books include Excel 2007 Power Programming with VBA, Excel 2007 Formulas, and the bestselling Excel 2007 Bible, all published by Wiley. He has also written hundreds of articles and created the award-winning Power Utility Pack. Visit Wiley.com to learn more about this book.

You probably already know how to hide a worksheet. However, to make it more difficult for the casual user to unhide a hidden sheet, you may want to find out how you can make the worksheet “very hidden.”