There's an article from a University of Utah publication back in like 1908 where they are calling the institution, "The U." Miami wasn't even founded until like the 1950s, but I get that their use of the term is way more prevalent in the mainstream as they were on such a big stage in the 80s and 90s. But I do believe Utah's use of the sign came out a few years before the Y adopted the hang loose sign. Not that it really matters. It's cool, use it.