what do the glovebox label codes mean?

does anyone have a comprehensive list of what each of the codes in the glovebox label means?  there seems to be a ton of them there, like 80 to 100 individual codes.  for example, if the seller of the car isn't sure whether it has heated mirrors or a limited-slip diff or even what the ratio is, the label should tell me that, right?  which code tells me what?  i'm shopping around for a used Av, and quite a few are out-of-town so they're not places i can afford to go visit more than once or twice - and i'd like to just have the cheat-sheet handy and be able to say "ah, this one has the 3.73 rear, but no LSD, and blah blah blah", esp when certain things i can't tell by just looking at the truck.

Resource tab on left under vehicle specs will show the codes, they do change dependant on vehicle year model.

http://www.chevyavalanchefanclub.com/resources/2006/specifications.html

Here is a thread with the codes. One list for 2002-2006 and farther down a list for 2007 and up.

http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,84494.msg1536742.html#msg1536742

thanks!  this should make my shopping a little quicker and easier.