What's this stamped number for?

[jeffvh]

I understand the VIN's and engine numbers, but what is the purpose of the number stamped on the body right above the coolant overflow tank on the 69 2000? The number stamped is 12010859.

Jeff Von Holten (SRL311-12920 owner since 1980, still learning about it...)

[spl310]

I don't know that anyone has ever figured it out. I have found other odd stampings of numbers - and they are different from car to car. On my 1500, I have found where an inspector initialed the car under the dash pad...