This sounds like a PRIVATE school playing games against PUBLIC schools.
If the school is private, they can do anything they want.
Counties in Louisiana are parishes. Napoleonic Code, French tradition and all that sort of thing.
A 'parish' is what they call a county in Louisiana as state law there is based on the Napoleonic Code as opposed to English Common Law.
The term "parish" is used in Louisiana instead of county. The practice comes from Louisiana's early history when the area was by law exclusively Roman Catholic and the government unit coincided with ecclesiastical districts.