[morzh]

nf is nano farad... 1/1000 of a pico farad, as I understand it... here we generally use mfd or mmfd, some modern folks use pf for mmfd and some folks use a u instead of the m because they think it looks more like a Greek mu for micro, silly, I think. I still say micro-micro farad for pico farad to this day, LOL, but then I'm old.

No it is the picofarad that is 1/1000 of nanofarad. 

Pico is ten to the minus 12, 

Nano  is ten to the minus 9.

Then there is femtofarad, ten to the -15, 1/1000 of the picofarad. Radios dontdeal with that but some devices do. I have a friend who measures those.

And no one needs Attofarads.