Illinois offers an "Other Adjustment" only if the IRS instructs you to include an adjustment amount on your Federal return that is not specifically listed on Form 1040, Lines 23-35. This is not a common line item.
If the federal adjustment is for an item of income (reported on Federal Form 1040, Lines 7-21, you may include a deduction to the extent that the income is included on your Illinois return.
If the federal adjustment is an expenditure related to income, you may include a deduction to the extent that the related income is taxed in Illinois.
If the federal adjustment is an expenditure unrelated to income, you may include the amount that you included on your Federal return.