Direction is a Manhattan direction.
All edges on layers that lie in the plow's path are pushed ahead of it, and they push other edges ahead of them to maintain design rules, connectivity, and transistor and contact sizes. Subcells are moved in their entirety without being modified internally. Any mask information overlapping a subcell moved by plowing is also moved by the same amount. The box specifies the area that may be modified by plowing. This area is highlighted with a pale stipple outline.