[MotorBikeLes]

I am not going to dispute the preceding arguments, BUT.
My understanding of RMS power, around and in general use for many decades, is as follows. A sine wave input to an amplifier comes out at a consistent amplified level (let us say 1v rms) and it is fed to a loudspeaker whose impedance is, say, 4 ohms. By taking an infinite number of samples of the voltage, squaring them, adding together then finding the square root, you have a mean voltage into the 4 ohms, yielding a mean power output.
Of course that must be a a fixed frequency, which must be at a frequency where the loudspeaker's impedance is the stated 4 ohms.
Certainly not correct for all frequencies that can pass the amplifier, and all the loudspeaker impedance presented at those different frequencies, but a comparison nonetheless.
It was a term happily used for all the stuff I looked at until about 30 years ago when it was *******ised into "music power" and then "Peak music power" and maybe others.
So putting aside the absolute mathematics of confusion, is it not a reasonable term to use?
Les, whose maths never really got beyond "O" level in spite of his 8 years at technical college.