NEC 225.19(A) vs 230.24(A)

[DimlyLit]

Why is there a 6" difference in allowable roof clearance heights for conductors over a roof? One requires 8ft, and the other requires 8'6".
What am I missing?

 

[augie47]

As to why the difference, no idea but 225 is for branch circuits and feeders whereas 230 is for services..
There are subtle differences between the two.