Is their any custody document that does not allow the child to move out after they are 18 while enrolled in high school?

Question

Is their any custody document that does not allow the child to move out after they are 18 while enrolled in high school?

Answer

Once 18, the "child" is an adult and, unless under a court guardianship or conservatorship, free to live independently. He/she is still governed by laws relating to school attendance (if any), but he/she is now an adult and can fend for him/herself. No money from Mom & Dad, though.