Neither. I have a car with a fender tag that mentions some codes that I have not listed in this post. I have no build sheet at all. I'm curious to know about the radio code that I mentioned in the OP because I have a code R11, which is for an AM radio in my fender tag but the car clearly came with a factory AM/FM mono radio. Have no clue what code that might be.....

The other items I'm just curious to know.