A new serial number marking system applicable to firearms identification

A new system for physically recording serial numbers on individual items is proposed. Each serial number is converted to a unique array of points, and this array is recorded on the item by drilling a set of holes having the arrangement of the array into the item. Laser drilling can be used to produce holes of small diameter for the array. The identifying marks extend into the item and cannot be readily removed as surface stampings. In some cases the serial number can be marked in a critical area, so that its removal would destroy the usefulness of the item. This system is particularly suitable for the marking of firearms.