Ways of validating data
In practice, this setting seems to effect only the command "circle invalid data".
When enabled, blank cells are not circled even if they fail validation.
Custom formulas greatly extend the options for data validation.
Decimal - works like the whole number option, but allows decimal values.
For example, with the Decimal option configured to allow values between 0 and 3, values like .5, 2.5, and 3.1 are all allowed.
For example, to restrict entries to the actions "BUY", "HOLD", or "SELL" you can enter these values separated with commas as seen below: When applied to a cell in the worksheet, the dropdown menu works like this: Another way to supply values to a dropdown menu is to use a worksheet reference. small, medium, etc.) in the range F3: F6, you can supply this range directly inside the data validation settings window: Note the range is entered as an absolute address to prevent it from changing as the data validation is applied to other cells. For example, with the named range called "sizes" for F3: F7, you can enter the name directly in the window, starting with an equal sign: Named ranges are automatically absolute, so they won't change as the data validation is applied to different cells.
If named ranges are new to you, this page has a good overview and a number of related tips.There are a number of built-in validation rules with various options, or you can select Custom, and use your own formula to validate input as seen below: The Input Message tab defines a message to display when a cell with validation rules is selected. If no input message is set, no message appears when a user selects a cell with data validation applied.