A more thorough explanation:

Custodial interference

Custodial interference is when a parent violates a court order regarding custody of their child. This can be as serious as taking the child away from the custodial parent or as minor as contacting the child more than allowed. Custodial interference is considered a crime in many cases, and taking a child or keeping them longer than allowed from the custodial parent can be considered kidnapping. However, if the action is taken to protect the child from harm or danger, such as during a natural disaster or to prevent violence, the parent may not be charged with a crime.

• A mother takes her child on a vacation without the permission of the father who has sole custody of the child.
• A father refuses to return the child to the mother after their scheduled visitation time has ended.

These examples illustrate custodial interference because in both cases, a parent is violating a court order regarding custody of the child. The mother in the first example is taking the child away from the sole custodian without permission, while the father in the second example is keeping the child longer than allowed. Both actions are considered custodial interference and can result in legal consequences.