The short answer
An edge crack and a stress crack are not necessarily the same. ROLAGS defines an edge crack as any crack that reaches an edge. A stress crack also begins at an edge, but it has no identifiable impact point. Stress or twist damage can result from movement within the vehicle frame or from an installation or mounting condition rather than a rock strike.
ROLAGS recommends replacement for stress cracks and for edge cracks that intersect more than one edge. A crack caused by an identifiable impact and reaching only one edge is not automatically excluded, but it must still satisfy every applicable size, location, layer, contamination, feature and technician-judgment requirement. The vehicle itself should also be assessed for conditions that could compromise glass retention. Do not press on the glass to search for an impact point. A technician can inspect both sides, the perimeter and the mounting area before deciding whether repair is appropriate.
