22. Protecting Your Workbooks
So far, you've created spreadsheets that are a bit of a free-for-all. You (or anyone else) can open them and change absolutely anything, from the most minor formatting detail to the most critical formula. For everyday Excel use, this freedom makes perfect sense. However, if you're thinking about sharing your carefully crafted work with other peoplelike colleagues who need to review your numberssome caution is in order.
In this chapter, you'll consider two tools that can help you build bulletproof spreadsheets: data validation and worksheet protection . Data validation catches incorrect values. Worksheet protection locks down your worksheets so they accept only certain types of changes in certain areas. Using these features, you can make your workbooks impervious to error (and deliberate fudging ).