General Order Number 10 of the 6th Regiment of Marines dated 15 February 1918 specifically stated, "The numbers assigned to all men present will be stamped in identification tags." There was some clarification in General Order Number 91, paragraph II, of 10 June 1918, which read as follows: The aluminum identification tags, each the size of a silver half dollar and of suitable thickness, will be worn by each officer and soldier of the American Expeditionary Force and by all civilians attached thereto. F., in 1917, will be issued until the present supply is exhausted.
20 December 1906 official stocklist number adopted in 1943. In 1942, the first tag is to be suspended on a necklace 25 inches in length, while the second tag is to be fixed to a separate necklace extension not further than 2 ½ inches under the first one – first models of tag holders were in cotton, plastic, nylon, rayon, the official “double-J” metal necklace was only introduced in 1943 (with hooks & catches) the bead type (initially sold at PXs) quickly became very popular and available in case of loss and gradually replaced the 1943 issue, it was made out of 2 lengths of stainless steel, of approximately respectively 28 inches and 6 inches in length, easy and practical for general use.Informal identification badges soon became popular, and soldiers used a variety of pins, tags, medallions, or other objects in which they engraved their names, hometown, battles they fought in, and other information.Dog tags weren’t standardized by the US Army until the early 1900’s, when the War Department authorized identification tags in War Department General Order No. It was in WWI that soldiers were first issued two identification tags.TAG 2” X 1 1/8” official dimensions: 2 inches (long) x 1 1/8 inches (wide) x 0.025 inches (thick).Rectangular form with notch at left (to position tag on the embossing machine) small rolled outer edges, and a single hole (dia 1/8″) for the necklace.It appears they were worn by some on a purely personal basis.