For children's tags, customers often replace the SS# with their home phone number and many customers put the child's home address in place of the last two lines.
In 1940, some dog tags were marked in the following manner:
1st Line - soldier's full name
2nd Line - his full seven or eight digit service number and date of any Tetanus injections (e.g., "T42" or "T41 42") and an initial to indicate blood group
3rd to 5th Lines - Address of next of kin and on the 5th line and to the right an initial indicating the soldier's religion.
In 1944 the next of kin details were discontinued because it was thought that they gave the enemy information. The seven or eight digits of the soldier's identification number on the second line were broken down as: first two indicate an area within the states, second two town, and last four identify the soldier himself.