What is a Petrus bad edge?
From CubeOosan
When using the Petrus method, the third step is to get rid of bad edges.
There are 7 edges not part of the 2x2x3. If an edge can be moved to its correct place using only the two free sides and it arrives in the correct orientation, it is a good edge. If it arrives in the wrong orientation, it is a bad edge.
