Welcome to the wonderful world of ASME Section IX; the basis of AWS B2.1. There are many parallels between the two standard, however Section IX provides more detailed information. For example, how an A-number is determined is pretty well explained in ASME Section IX. AWS B2.1; not so much.
The weakness of ASME Section IX and AWS B2.1 is the welder is not given much consideration. Section IX is written by engineers for engineers. So, variables like voltage, amperage, etc. are largely ignored unless notch toughness is a consideration.
The saving grace is that the code lists the minimum requirements that must be met or in this case, the minimum information that must be recorded or presented by the PQR and WPS. There is nothing preventing the user from recording more information. I personally think it is pretty silly to go through the effort of qualifying a WPS and not record the welding variables used, i.e., groove angle, root opening, voltage, wire feed speed, amperage, travel speed, etc. After, those variables might come in very handy when writing the WPS.
I cannot remember how many times I received phone calls or emails with the question, "I qualified my procedure, but where do I find the voltage and amperage for my WPS?"
I usually ask, "Didn't you record that information while the welder welder the coupon?"
The response, "The code doesn't require a witness, so I didn't witness the welding, so how could I record that information?"
"Silly boy." is my usual reply.
Best regards - Al