20-180.2 (C)(4)  Income received by the payor from secondary employment income not previously included in "gross income," where the payor obtained the income to discharge a child support arrearage established by a court or administrative order and the payor is paying the arrearage pursuant to the order. "Secondary employment income" includes but is not limited to income from an additional job, from self-employment, or from overtime employment. The cessation of such secondary income upon the payment of the arrearage shall not be the basis for a material change in circumstances upon which a modification of child support may be based.