When do you need to create a custom list for use with Excels Auto Fill feature?

You need to create a custom list for Excel's Auto Fill feature when you have a specific sequence or set of values that Excel does not recognize as a standard list, such as days of the week or months. This is common for unique lists like project phases, product names, or custom categories. By defining a custom list, you can easily populate cells with these specific values, enhancing efficiency in data entry. To create a custom list, go to the Excel options and input your desired sequence in the Custom Lists section.