I’m sure that by now this is old news, but I wanted to share it with the community at-large. The more this information is out there the greater the chance to keep instant photography thriving and alive.
This first site is PDF straight from Polaroid explaining the codes found on the back of their instant photos. This includes both peel-apart (pack-film) and integral film. This 55 page document (dated 1998) does a thorough job of explaining the various codes found on the backs of Polaroid pictures. I never gave much thought to these codes and assumed they only meant something to the manufacturer.
I don’t know the author of this website and would like to give credit where credit is due. So, please leave a comment or email me with the site’s author/creator.
A more succinct explanation of the codes can be found at another website. This five page PDF document includes illustrations with examples.
Polaroid Date Codes with Illustrations
Here are several examples from my own collection of family Polaroids with their codes explained.
My Polaroid Blog 