a) I use OrCAD, and it assigns part numbers based on the order they are placed on the sheet(s). Seems to be OK. b) for MOTM, these are my own set of rules vias are 50/30 (50mil pad/30mil hole) pads are 70/40 signal traces are 16mil power/ground are 100mil 'main lines' then 30mil to pads Paul S.