In Jackson v. Jackson (1975) 51 Cal.App.3d 363, a noncustodial parent (the father) provided a home and financial support for his daughter in excess of the court-ordered support obligation. The court concluded the father, by assuming exclusive and sole custody, had "expended amounts well in excess of the court-ordered $ 750 per month." (Id. at p. 368.) The court reasoned: "While it is true that an order for child support may not be retroactively modified (Civ. Code, 4700) and that accrued arrearages are treated like a judgment for money citations it must be remembered that such orders are an exercise of the court's equitable power and are designed to compel satisfaction of the child support obligation which exists apart from the marriage status. The obligation is to the child and not to the mother. " (Jackson, supra, 51 Cal.App.3d at pp. 366-367.) The Jackson court held: "The purpose of the child support order was to insure that the daughter was properly cared for and was not to provide mother with a weapon to be used retributively against the father. Thus we conclude that the trial court would have been well within its discretion in recalling and quashing the writ of execution or permitting only partial enforcement on the basis that the father had directly discharged his obligation or on the basis of equitable considerations." (Jackson, supra, 51 Cal.App.3d at 368.) In short, custody of the parties' child was awarded to wife, and husband was ordered to pay child support. Custody of the child was transferred to husband with the consent of wife, but without an order modifying custody or support. Husband ceased paying child support. Later, wife obtained a writ of execution for 22 months of unpaid support, dating from the time husband took physical custody. Husband moved to quash the writ. The trial court denied the motion on the ground it had no jurisdiction to retroactively modify support. The Court of Appeal reversed. It agreed the trial court had no jurisdiction to retroactively modify support, but held it had equitable powers over the enforcement of the support obligation. Thus the trial court had the discretion to find husband had discharged his support obligation by providing the parties' child with a home as wife had agreed. (Id. at p. 368.)