To All from PA0SE

On my question about the proper way of writing units in English/American I
received the following reply from the Editor of RadCom.

73, Dick, PA0SE


Hello, Dick.

It is RadCom style to use the following:

10V or 10 volt(s), 5A or 5 amp(s), 2W or 2 watt(s).
With IF, RF and AF, capital letters and no dots.
With frequency, no gap between the number and the units, ie
800Hz, 136kHz, 21MHz.

Steve White, G3ZVW

In The Netherlands we write 5 A, but 5 ampère, 10 V but 10 volt. So in
general the unit is written with a capital when abbreviated but with a
lower case when written in full. And with a space between figure and unit.

What is correct in English or American, 3 V or 3V?.  Same question for 10
amp, 10amp, 10Amp, 10Amps?, etc.

And what about rf or RF? if, IF, i.f. or I.F. (intermediate frequency)
etc.?

73, Dick, PA0SE