You obviously don't know what I meant.Split boards were very common.
Dual boards were not.
You know what I meant....
Split board - switch (or 100mA Type-S) incomer, with 1 RCD downstream of that. Very common before the 17th.
Dual board - switch incomer, two completely separate sections each with an RCD, neither RCD downstream of the other. Not very common before the 17th.
Got you......thanks