I saw the following comment on another site that addresses how a particular situation was handled in Texas, regarding a couple of Private schools.
The UIL allowed Houston Jesuit and Dallas Jesuit to join the association due to years of asking and the fact it was too difficult for them to find competition in Tapps for state playoffs. One year the basketball Tapps largest division had only four schools in the entire state in the playoffs. So here are the rules as told to me by Dallas Jesuit parents at a track meet.
1.They must play in the largest division, which was 5A, but they are now in 6A. Today was Realignment Day, so everyone in Texas found out their new district. Jesuit has 2214 students(1100 boys plus 1114 girls at Urseline) which is the smallest 6A program in North Texas. 2199 is the cutoff from 5A. They are located one block from the Dallas Galleria, so they are in a league of DISD schools, but Skyline and Berkner are really good programs in all sports.
2.They must keep their admission standards. This is where I feel the LHSAA has failed miserably. In other words, for the past 77 years Jesuit students must take an admission test to get in during the spring of their 8th grade year. They must have a certain GPA in Middle School, etc. They do have hardship scholarships, but it illegal to give athletic scholarships. Tuition is $16,200 a year, so alumni board wants to keep it an academic institution and help those that are financially in need, but have kids who qualify for the school.
They give out $2 million in academic aid, but no athletic aid. Test scores and GPA as well as middle school recommendations. In other words, they offer 20 varsity sports and 80 extracurricular activities for all students. They are all male and they mix with Ursaline Academy, one of the best All-Girl prep schools in the USA. They have girls from overs-seas and they have dorms. There are NO props coming out of these sports programs.
3.All coaches must be full time employees. No McDonough 35 deals where three coaches don't even work at the school.
4. Attendance zones are set up by the UIL to mirror the closest public school. Athletes out of zone must sit for one year.
The rules have kept Jesuit clean , plus they are 77 years old and are known for academics, so alums are not worried about winning district championships. They have done well in baseball and football, making the playoffs just about every year. They will not get past round two because they will start to meet much tougher competition.