A dog tag is also the colloquial name for the identification tags worn by military personnel, especially in the United States. In the US the name, military id number, blood type and religious preference are stamped on a small piece of metal that is worn on a metal chain around the neck. During World War II, certain medical information such as the date of the soldier's last tetanus shot was also included on the tag. The tag is primarily used for the indentification of dead and wounded.
Wearing of the tag is required at all times by soldiers in the field. It may contain two copies of the information and be designed to break easily into two pieces. This allows half the tag to be collected for notification while the oher half remains with the body when battle conditions do not allow the casualty to be immediately recovered.
Dog Tags in History
Dog tags were worn at least as far back as ancient Sparta.
During the American Civil War of 1861-1865, some soldiers pinned paper notes with their name and home address to the backs of their coats. Other soldiers stencilled identification on their knapsacks or scratched it in the soft lead backing of the Army belt buckle.
Manufacturers of identification badges recognised a market and began advertising in periodicals. Their pins were usually shaped to suggest a branch of service and engraved with the soldier's name and unit. Machine-stamped tags were also made of brass or lead with a hole and usually had (on one side) an eagle or shield and such phrases as "War for the Union" or "Liberty, Union, and Equality." The other side had the soldier's name and unit and sometimes a list of battles in which he had participated.
A New Yorker named John Kennedy wrote to the US Army in 1862, offering to furnish discs for all officers and men in the Federal Army, enclosing a design for the disc. The National Archives now has the letter along with the reply, a summary refusal without explanation.
In the Spanish-American War, soldiers purchased crude stamped identification tags.
The US Army first authorized identification tags in War Department General Order No. 204, dated December 20, 1906, which essentially prescribes the Kennedy identification tag: