My kids are at a public charter school, and the school is not allowed to discriminate - the enrollment forms are basically identical to the enrollment forms at the neighborhood public school. Entry is determined by lottery. And yet, I have heard of gifted charter schools elsewhere, not in our school district (I have never really looked into it).
My guess is that the gifted charter schools that were grandfathered in are more like "magnet" schools which, I believe, are allowed to discriminate based on test scores, or at least they did historically. I recall hearing about "magnet" schools decades ago, while charter schools are a newer phenomenon. The difference may be that the magnet schools are run by the school district, while the charter schools are not. Come to think of it, our district has a full time gifted program that requires test scores, among other things, and operates like "magnet" schools in that there are only a handful of locations at which they operate (out of the 30-ish elementary schools).
