RMS Power?

In Radiography (x-ray), the characteristics of the beam are controlled by varying the kVp across the x-ray tube and the mA in the filament.
The actual dosage to the patient is really dependant on the mA and kV rms, as is the amount of contrast in the image; analogous to dynamic range in audio.
The kV rms varies greatly with the quality of the power supplied to the input of the transformer and even more with the form of rectification. Since the degree of rectification varies so greatly with various audio technologies from tubes to op amps to class D, maybe RMS is at least as meaningful as peak.

....or maybe radiography and audio have nothing in common and I'm full of s#!t. Happens all the time.

The kV rms varies greatly with the quality of the power supplied to the input of the transformer and even more with the form of rectification.

What is "quality of power"? Do you mean amount?
Is "form of rectification" - full wave or half wave?

Since the degree of rectification varies so greatly with various audio technologies from tubes to op amps to class D, maybe RMS is at least as meaningful as peak.

What is "degree of rectification" and how is it related to op-amps or class of the amplifier? RMS of power does not represent anything useful. Your kVrms * mArms is just power.

...or maybe radiography and audio have nothing in common and I’m full of s#!t.

You’re not. Asking questions is important.

While it's interesting that the term RMS power is a misnomer, it is at least consistent. We are still at least comparing apples to apples. I suspect that's all most consumers care about. As long as I know everyone is using the wrong term in the same way, knowing that one amp is rated at 25 wpc rms and another is rated at 80 wpc rms, that is providing me, the consumer, useful information. 

Zavato, amp is rated 80watt and marked 80watt rms by mistake.  In watt rms it would be 97.6 watt.  Vrms*Irms=Pavg  NOT Prms.

@kijanki  I often see power specifications like "100W RMS".  There is no such thing as RMS power.  Of course, you can calculate RMS value from any curve, including power curve, but it won't represent anything.  "Real" power representing heat dissipated in resistive load is "Average Power"   Pavg=Vrms*Irms.   In case of sinewaves Pavg=0.707Vpeak * 0.707Ipeak = 0.5Ppeak,  or Ppeak = 2Pavg.

Term "RMS Power" or "watts RMS" is a mistake, very common in audio.

Where is the mistake in RMS power?

RMS is a measurement that allows one to determine the peak value of a sine wave that will produce the same heating in a resistive load as a DC voltage. So if run a heater or incandecent bulb off 120 DC or 120 RMS AC the heat and light will be the same. The peak voltage of that sine wave will be 1.414 X 120 about 170 volts. By the way the average of a 170 volt sine wave is 0.637 X 170 or 108 volts. This is all well documented and accepted. 

What is it you are going on about anyway? I make 100 Watt amplifiers and I know how to measure them.They produce 28.28 Volts RMS into a 8 ohm load. 

Perhaps you missed the fact that at the peak the instaneous power is very large and not related to the average voltage.