Clarification needed for NC State for "addition to income in NC handled differently from Federal"

There is a question on the NC return that is very confusing because if you enter income as stated in the "learn more" help topic, you end up getting taxed on NC income that is supposed to be exempt.

 

Its under "Addition to income in NC handled differently from Federal"

You are prompted to enter Expenses Allocable to Income Exempt or Excluded From Gross Income

but under the "Learn More" it says

Enter the amount of expenses allocable to income NOT SUBJECT to North Carolina income tax.

 

This makes absolutely no sense, why would I want to add income  that should not be taxed in NC? This flows directly to the NC taxable income!