Some people have an unhealthy obsession over the tiniest, most insignificant things.
In this case it's probably about using U vs V for voltage (U is eg. more commonly taught/used in Europe and is recommended by IEC norm 60050 [1], V is more commonly taught/used in North America ; there might also be different conventions in different industry branches). In the grand scheme of things it doesn't matter of course, but you know, we are on the Internet.
Electric potential is V according to that site [1]; though im not familiar with whatever minute differences U vs V is in Ohms law...growing up I learned it as E or V.
In this case it's probably about using U vs V for voltage (U is eg. more commonly taught/used in Europe and is recommended by IEC norm 60050 [1], V is more commonly taught/used in North America ; there might also be different conventions in different industry branches). In the grand scheme of things it doesn't matter of course, but you know, we are on the Internet.
[1] - https://www.electropedia.org/iev/iev.nsf/display?openform&ie...