Pobs, I found this info:
Erkennungsmarke: This was the standard issue German military identification tag, often called a "dog tag". The Erkennungsmarke was instituted and first issued in August of 1939 to all members of the German Wehrmacht. Thereafter, the tag was issued to all soldiers shortly after they were first inducted into the Wehrmacht. The tag itself consisted of a thin aluminum, zinc, steel, or tin oval disc that was worn around the neck on a chain, string, or lace. Wear of the tag was required at all times by all soldiers in the field or field conditions. It was perferated in the middle and was stamped with identical information above and below the perforation line. The tag was designed to be broken in two pieces when the soldier wearing it was killed. The lower half would be collected if at all possible, and given to the unit HQ for grave registration and notification. The upper half would remain with the body itself. The information on the tag varied throughout the war, but generally consisted of the designation of the individuals initial replacement unit (the unit all soldiers were inducted to before being sent to a regular field unit), a soldier number, and the soldiers blood type. Initially, all German units of Kompanie size were required to maintain complete lists of all soldiers and their Erkennungsmarke. These lists would be updated as needed once a month with any additions and subtractions based on men lost as KIA, MIA, through transfers or sick leave, or that were gained through replacements and transfers or soldiers returned from sick leave. This offical Kompanie listing was registerd with the German Armed Forces Information Office for Casualties and War Prisoners, and was kept as up-to-date as possible.
You can see an image of a tag to help make sure we are looking at the same thng. Go to this site:
http://www.feldgrau.com/soldier-id.htmlCJ