From the '23 NEC "Qualified Person. One familiar with the construction and operation of the apparatus and the hazards involved."
The only change in this definition from the '23 NEC to the '99 is the replacement of the word "apparatus" with "equipment".
I quote from the '23 NEC because I do not have a copy of the '30 NEC, which is the edition the Three Stooges would have used had they been "qualified persons" and actually read a codebook.
One of the happiest moments of my misspent youth was when I was about 8yrs.
I actually got to go to the Grand Opening of "The 3 Stooges meet Hercules" and see them in person. It was the best thing in the World to me, and still is