Four Layer Design Rules (traces and spacing)

Hi Guys,

I just submitted a 4 layer design to the DRC bot. All layers were identified properly and passed the Gerber check. But when the DRC email came back it failed to meet the minimum 8 mil trace, 8 mil spacing rules. I thought the minimums for 4 layer boards were 6 mil traces, 6 mil spacing. Is the FAQ out of date or is there something else I need to do when submitting a 4 layer design?

Regards,

Brian.