On Friday, October 14, 2016 at 11:09:40 PM UTC-6, Hot-Text wrote:

/u Is A Lie

Not quite accurate, but neither is telling the user that it will show up with /? switch applied to format command. The truth is that /U is the new /C.. For whatever reason they decided /C was more better, but at the same time left the /U switch working for /C switch for those of us used to using /U.. Same, same is the result only now /U is an undocumented switch. Description of /C is lacking as well but then so was /U description back when it did show up in earlier versions of DOS.