Thanks for bringing this thread back to the front, Delmar. I like the certificate idea.
Here in PA private schools have access to a lot of special-ed and learning disability resources from the public school system. I don’t know much about the process, but students with extraordinary academic struggles can be given what’s called an IEP (which I think stands for Individualized Education Plan, or something like that). Our school works with the state agency to evaluate the student’s abilities and devise an IEP that will maximize his potential. Those who perform adequately according to their IEP receive a special diploma that notes how their course of study differed from the regular course. Again, I don’t know much about this, and I may have gotten some details wrong, but that’s the gist of it.