Not quite sure what you mean by "explain the (3) sections that sentence is referring to?" But I would think the code would allow the reduction of the feeder grounded conductor size amounting to 30% of the range, oven, cooktop and dryer load. It's written kinda goofy but the handbook explains it a little bit. The feeder grounded conductor can be reduced the way I read it. Based on the type of feeder being a Delta.
