~~~ or simply an incuse security feature.

The machined/auger incuse is only as deep as half the thickness of the protective layer where the underlying grapic is untouched.

I've neve seen this before and have nothing similar to compare it to, but I have been told that some of the lower denom jetons of the series carry this on one side, but I've not seen any.

If it is a cancellation, it is rather mild and doesn't take too much awy from the piece as would a drillhole. Kind of thoughtful...