The School Enrollment Form is best if your child goes to school in boundary, it will be good for the career of the athlete or until school enrollment changes:
https://acrobat.adobe.com/id/urn:aaid:sc:US:a10a15ad-05b4-421a-ad5f-3351bcd94277The following link explains appropriate documents for home Proof of Residency requirements:
Proof of Residency