The rules that you applied since the editor opened. They are in edits.csv.
The rules of edits.csv from before. Click a row to show its two roads; delete puts it in the list to apply.
The roads with their own head lengths or end shapes, as they are now, with the time of each road's last change. Reset puts the defaults in the list to apply.
A crossing that the solver could not keep: a flaw on the map.
A road that only comes near the road below it. Look only where the two overlap.
An order that a stack or another order won.