ErrorCheckingOptions.BackgroundChecking Property (Excel)
Alerts the user for all cells that violate enabled error-checking rules. When this property is set to True (default), the AutoCorrect Options button appears next to all cells that violate enabled errors. False disables background checking for errors. Read/write Boolean.
In the following example, when the user selects cell A1 (which contains a formula referring to empty cells), the AutoCorrect Options button appears.