I had a mouse that moved in between the hood and the hoodliner. in my 1980 Cutlass.

When I removed the old liner (the mouse took off) I noticed a document that was taped to the underside of the hood. It doesn't have a title to it but it has a 2 or 3 digit code for just about every piece of the car...radio, steering, interior colors, mirror color, air cleaner, wheel lug nut...EVERYTHING

Does anyone know anything about this document? Is there a list somewhere identifying these codes? They might be useful when looking for parts.

 

That is either a build sheet or a broadcast card. Keep it safe and nice, because it, like you said, details what the car comes with, and that is provenance for proving a car is the way it was. Not such a big deal on every car as much as the rare ones, but it is still a very important part of your car's history. Save it!

 

What year and model of car?? Can you post a picture of it?
Sounds like you might have found a list of RPO codes (Regular Production Order). Yes there are lists available for GM.
RPO (GM) Master List

 

The camera sucks on my phone but this is what the document looks like and I took some crappy close-ups as examples.

• The first photo shows the full sheet
• The 2nd photo outlines all of the options
• One photo is of the Power Steering section and I have the code "CM" for the pump. For the pump belt I have an "SL"...right below that, the radio has a code "U58"
• The transmission cooling pipes have a code XR" for the lower, and "XP" for the upper...also we can see that the steering column has a code "YX".

It seems that this paper identifies everything which is really cool. I am hoping to find the parts list match up to these codes. I checked out the master list link Allan provided and the stuff for this '80 Cutlass doesn't seem to be on there. If anyone knows anything aout these codes please share your thoughts

 

Holy cow, is your car's VIN on there? Body Tag info?
Or, is the hood from another car?

Lucky man!

 

What you have is the "build sheet" for the car. The 3 digit codes in the lower half (generally letter-number-number) are RPO codes. The 2 digit alpha codes are broadcast codes for components. The broadcast codes are plant use only and are thus harder to decode.
You'll have better luck scanning the sheet rather than taking pics. You should find your VIN and cowl tag body id at the top of the sheet.