This is a command to offset a polyline and put the offset
polyline into a separate layer from the original
polyline.
Offset to layer <0>: ROW
Enter the offset amount: 20
Select object to offset: pick
a polyline to offset
Specify point on side to offset: pick a point
Pulldown Menu Location: Edit > Offset
Keyboard Command: offset_layer
Prerequisite: Linework to offset