That seems to be the case with linguistic- and group practices in general. It's not universal law, and while the overlap of correctness and even best practice is pretty big, there are still differences. Subject matter, language, abstract institution (universities), concrete ditto (Oxford, Chalmers, Max Planck IoT, Royal Academy of {country}), register/style (daily newspaper, tabloid), etc.

Fair enough. I first learned of it on law review in law school, from the Texas Law Review’s Manual of Style.

This is very common parlance in law