In my elementary school, we weren’t given grades of A B C D F as was the standard before and since. Instead, New Haven R-II school employed a different set of letters that meant the same thing. They were E S M I F. I have no idea how this came to pass, but I hope it was because some person seeking a doctorate in education realized that his dissertation was due tomorrow and he had nothing. Frankly, I could get behind that kind of education theory. Beats modern pedagogy, anyway.