K-member coin looking tags???

[BossBird]

Have removed quite a few k-members. Never understood what these coin looking things represent. Have seen them, have not seen them. Found one car with 3 of them.

 

[Kern Dog]

It was a fast way to attach a part number without stamping the K member.
My 70 had a 90 on it, denoting the last 2 numbers of the part #.