Schedule AD is used to report differences between federal and Wisconsin income. These differences are called modifications and may affect the amount you report as an addition modification on line 2 of Form 1. If the form is being populated, then you must have selected Wisconsin as a State - leading me to believe you either reside in Wisconsin, or you work there. Either way, this form is basically asking you what portion of your income is attributable to Wisconsin ("related to"). That way, if none of it is taxable to Wisconsin, you need to identify this information on this screen. If there is nothing to enter and the system will not allow you to e-file without entering something, I would need to know a little more about your situation. This should at least help you to understand its purpose.
