Although millifarads and mF are technically correct to express one thousandth of a farad,
I've never seen them used in practice.
Of interest to me is when to capitalise (or not) the first letter of the unit.
e.g 3.3 V, but 3 volts
I think when you use the symbolic abbreviation it is usually upper case (V, A, mA, uF,...)
but when you spell it out you use lower case (volts, amps, ...) even though it stems from someone's surname. Go figure.
And on the subject of multipliers and dividers in prefix, it's always handy
to express time in apparent useless denominations ...
e.g. a weekend be referred to as ~170 kiloseconds,
or a year might be 32 megaseconds
a coupe of minutes could be 1.5 microdays
endless fun for confounding nontechnical management