Here is the issue. I called out a double tap on the main 200 Amp breaker. The main wires are aluminum (with protective coating) and the wires that double tap the main going to the sub-panel next to it are copper. I have a realtor that claims he has called a retired electrician and said it is not a normal practice but it IS acceptable. Can someone tell me how to word this so I can get through to the realtor that the retired electrician, he, or even me are set straight. Over 8 years I have never had an argument when I come upon this issue. So it’s a double tapped Main breaker with aluminum (with protective coating) and copper on the same screw (lug).
Give me a link, the NEC on it, or proper wording. Thanks