I didn't have a clue what that meant so, I took the liberty of looking it up and here is what I found.  First, it is a way they WON'T have to pay your son what they owe him....but here is the whole explanation.  GOOD LUCK.  Hope that your lawyer stick it to them.  They need to pay for all of your trips as well. GEEZ

abstract of judgment n. a written summary of a judgment which states how much money the losing defendant owes to the person who won the lawsuit (judgment creditor), the rate of interest to be paid on the judgment amount, court costs, and any specific orders that the losing defendant (judgment debtor) must obey, which abstract is acknowledged and stamped so that it can be recorded and made official with the government. The purpose of an abstract of judgment is to create a public record and create a lien or claim if necessary on any real estate property owned or later acquired by the defendant located in the county in which the abstract of judgment is recorded. If the loser does not pay the judgment voluntarily then the winner can force a sheriff's sale of any property to collect. There are several problems: 1) to find the county where the loser owns real estate property; 2) the probability that there are secured loans, tax liens and/or other judgments that come ahead of the judgment lien; 3) the possibility that the loser/debtor may go bankrupt and avoid paying the debt.