MV is Mega Volt
mV is milli Volt
Mv or mv do not exis. v is velocity.
Mhz and mhz do not exist, MHz and mHz do.
C is capaitance in F , c is light velocity in m/s, but C is also Coulomb, the unit for Q, charge.
S is siemens, s is seconds so it is ms and Ms or mS and mS
E is Elctric field strenght in V/m, here m is meter
Volt, Ampere ect are named after people that is why we use captials, exeptions make the rule,
e is Euler
atto, femto, nano, milli are smaller then the unit so small letters
Mega, Terra, Peta are bigger as the unit so a capital letter.
Also used wrong are the h parameter for transistors. It is h not H and the subscript is important too, FE is for DC amplification, but fe is relative for small signal. So two totaly different things.
If we follow these simple basics we are all talking about the same thing. You maybe write mHz out of lazyness or because you do not care or know and because you never work with mHz but some of us do and I have seen a discussion where the starter used mohm and everybody assumed he was talking MOhm. That took more then a page of non usable anwers. He meant mOhm ( milli Ohm, a small part of a Ohm)
This is nothing to make jokes about or say you do not care or it is not important. This is so basic everybody should know and so important everyboy should apply these rules ( or at leat try, everybody can make mistakes)