In many situations in this country a person can willingly waive any legal requirement or defense so long as the waiver is made knowingly and with informed knowledge. In many cases lawyers have tolling agreement signed by each other on behalf of their clients extending the period of the time for the statute of limitations defense while attempts to settle a dispute are ongoing.In the situation that you are writing about the stipulation wpuld appear to refernence his agreement to remain under court supervision for whatever the case is about where there is an order in effect for monthly payments that he agreed to apparently. If the period of time for court supervision in your son's matter exceeds twnety (20) years and for payment during this time period of twenty (20) years, your son's signing of the order would not extend the time period to retrieve the payment.If there is a failure to pay by your son on an obligation under the order, the time period to obtain the period would start then.