I wanted to get collar disks to go with my WWI tunic so I did my usual eBay scanning and picked up these and a US disk in a separate auction. These are not all WWI disks, the two middle ones are early 20's and the bottom one is late 20's.
I believe the top left has something to do with mules. Mule skinners, transport, I don't know. I've found one other on the net but no real information on it. Probably not a very common one.
It is very tempting to start collecting these but I'm thinking i better steer clear. I collect too many things already.
https://www.milsurps.com/images/impo...qU1lopng-1.jpg
https://www.milsurps.com/images/impo...Z9oaApng-1.jpg