I havent researched the issue. InshAllah I will. But even if Uthman brought this in, with no basis in the sunnah whatsoever, which I highly doubt, then the prophet salallahu alayhi wassalam said follow my sunnah and the sunnah of the khulafah rashidah so this doesnt present any sort of problem for me because I consider uthman to be someone who's example should be followed in and of itself