4 layer DRU rules - min width 8 mil ?

Hello,

I have checked the DRU file for 4 layer fusion service and the wire clearance values are all set to 8 mil.
On the specs webpage, they are listed as 6 mils

Can you please tell me if I am missing something?

thanks

6 mil would be the minimum and you are less likely to have problems if you use 8 mil. This is quite common with low-cost PCB suppliers - they prefer slightly larger clearances than the minimum.

6 mil would be the base and you are less inclined to have issues in the event that you use 8 mil. This is very basic with ease PCB providers - they incline toward somewhat bigger clearances than the base.