In joint custody both parents are custodial parents and neither parent is a non-custodial parent, or, in other words, the child has two custodial parents.
Thus, the spouse given custody (or the spouse with the greater share of residence time in the case of joint custody), may receive assets to compensate their greater child-care expenses.
In joint custody, both parents are "custodial parents" and neither parent is a non-custodial parent; in other words, the child has two custodial parents.