Well, "m" is reserved for "milli". Using a QWERTY typewriter (remember
them?) or ASCII computer keyboard IMO "u" is the better substitute for
"micron". But "p" and "n" are on all those keyboards. So there was/is
no need for the above "mmF" construct, or awkward notations like .005uF
when 5nF would say it much nicer.

73, Eddi ._._.
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Yes, but for some reason 5nF was not of common use before about 25 years ago.
..005uF or 5kpF was the standard, who knows why..

Tony I0JX