Stamped code on trunk lid

[Stillwater Camaro]

I am sure I saw a topic on how to decode this on here a while back, but I can't find it again.
Also, is there a description/pictures of the different styles by year to better identify the lid ?
thanks........

[JohnZ]

That's the Fisher Body "run number" - the first letter identifies the stamping plant, and the number is the week of the calendar year when the panel was stamped.