Instructions
Search for an enemy standing near an inanimate object like a box, barrel or other object that could be damaged by a bullet.
Take aim at the object then wait for your opponent to move close to the item -- it is essential he is within a few feet of the inanimate object you have in your sight.
Shoot at the item. It will explode into shards. You will earn a classified kill if one of the pieces impact your opponent with enough force to kill him.
Throw a grenade at your opponent (or cause an explosion) that blows him off the map, resulting in him plummeting to his death. This is also considered a classified kill.