The “notch” was created out of necessity to accommodate a machine-the Addressograph Model 70, manufactured by the Addressograph-Multigraph Corporation. The Addressograph Model 70 was a clunky, heavy, hard to maneuver piece of equipment that looked like a pistol.
The notch allowed medics to properly position the tag on the Addressograph so they could imprint identification information from the dog tag onto military paperwork.
Myths and Rumors
Most myths and legends about the notch center on the use of putting dog tags inside the mouths of dead soldiers.
Some believed the notch was there to use the soldiers front teeth to hold the dog tag in place. In cases where rigamortis had set in, myths spread that the notch helped the soldier who discovered the body to maneuver the dog tag into place. Some even believed the notch helped the mouth stay open to allow toxic gases to escape so medical forces responsible for retrieving bodies wouldn’t risk contamination.
Here’s one more for the rumor mill. Because the Addressograph Model 70 looked like a gun. Some medics used it in extreme situations to ward off enemies.
The End of the Notch
ID tags issued after the Vietnam War do not have the notch. The military discontinued using the Addressograph machines, so there was no further need for the notch. The dog tag term is also out. The military prefers to call them “ID tags” to be more politically correct and disassociate such an important item from derogatory analogies.