In the DRC check rules box, is there a way to have more than one set of clearance rules for tracks? (In Kicad this is called 'Net Classes'.) For example, suppose I have a PCB with a 240V AC mains input, 5V output DC PSU on it and some small signal circuitry supplied from the PSU. Then for the small signal (5V) tracks I would like rules of 10mil track, 7 mil gap but for 240V AC Mains around the power supply input I may want different rules of 100mil track with 700mil gap. :)