The standards used by IEEE are;
- Long form text is always lower case
abbreviations of a name are always capitalized, to indicate reverence to names, such as tesla (T), henries (H) and pico-coulombs (pC) as opposed to second(s) which is not named after someone.
Greek abbreviations are capitalized as a rule for large positive exponents +6,+9,+12...+24 and lower case for negative exponents or powers of 10, which extends to 10^-24.
Thus Y= yotta down to 10^-24, y=yocta
- one exception is K was already assigned to Kelvin lower
e.g. kilowatt (kW), nanosecond (ns), nanosiemen (nS),
- the other exception is 10^-6 is the Greek letter "mu", μ.
"mu" is spoken as micro as in uF or μF where often the font is substituted with lower "u",
- sometimes ASCII range are imposed (eg 8 bit to 7 bit) and we see Greek font letter Ω, which is ANSI letter W and 100Ω shows by mistake as 100W. Thus the "long form" 100 ohms is "error free" when plain text is sometimes stripped down such as plain text.
e.g. exp.=+6= M = Mega, and exp. = -3= m = milli
The trends of english when society creates new words are;
- Introduction phase... separate words
- Frequent usage .. Hyphenate the words e.g. Never-the-less watt-hours
- common words .. Combine into one new word. e.g. watthours which looks confusing with "th", so this version is not popular for some, but is now "NIST" and IEEE/PES standardized