A more thorough explanation:

Split custody is a type of custody arrangement where parents divide the custody of their children between them. This means that one parent has sole custody of some of the children, while the other parent has sole custody of the remaining children. Split custody is not common because it is generally not considered beneficial to split up siblings.

However, there are some situations where split custody is the best option. For example, if there are children who are very combative or abusive with each other, one child has serious mental health problems, or it is otherwise impossible to parent them together all the time due to their joint behaviors, parents can choose to engage in a split custody arrangement. Another common situation where split custody is implemented is when one of the children is an older teen and wants to live with the parent other than the primary custodial one.

In order to get split custody, parents must ensure that their state laws allow for it, they must agree on the custody arrangement, and they must show the court that split custody is the best way to serve the interests of their children. The court will look at a number of factors before it will allow a split custody arrangement. In some states, these are listed in the split custody laws. In others, the court will use the "best interests of the child" standard to see if it is right for the children. Note that even if the parents agree on the arrangement, the court may not approve it.

For example, if a family has three children and the parents decide to split custody, one parent may have sole custody of the oldest child, while the other parent has sole custody of the younger two children. This arrangement may be necessary if the oldest child has a strong preference to live with the other parent and the parents agree that it is in the best interest of all the children.

Another example is if two siblings are constantly fighting and it is affecting their mental health and well-being. In this case, the parents may decide to split custody so that each parent has sole custody of one child. This way, the siblings can have a break from each other and hopefully improve their relationship over time.

Overall, split custody is a custody arrangement that involves dividing the custody of children between parents. It is generally not common, but may be necessary in certain situations where it is in the best interest of the children.