Fracture ala signature is

Depressed fracture(Fracture ala signature):When a poion of fractured bone is driven inwards to a distance equivalent to the thickness of the skull table *Heavy weapon with a small striking surface Ex:- Hammer, stone, chopper * Due to local deformation of skull. * It is also called 'fracture ala signature' (signature fracture), as the shape often points towards the shape of the offending weapon. Gutter fracture: seen in oblique bullet wounds Ring fracture- Fracture around the foramen magnum