1996 Cadillac Eldorado Owner's Manual - Page 63

The square key is for the ignition only. It has a re.sistorpellet which is part of the vehicle's PASS-Key@% system. When a new Cadillac is delivered, the dealerremoves -the plug from thedoor key. The plug has a codeon it that tells the dealeror a qualified locksmith how to make extra keys. The ignition key has a bar code tag attached to it rather than a knock out plug. Your dealer or qualified locksmith can make extra ignition keys by reading the bar code tag. There are 15 alternative ignition PASS-Key 1 blanks to 1 help discourage theft. Keep the bar code tag and the door key plugs in a safe place. If you lose your keys, you will be able to have new ones made using the plug or bar code tag. The oval key is for the doors and all other locks. ~~ NOTICE: Your Cadillac hasa number of new features that can help prevent theft.You can have a lot of trouble getting into your vehicle if you ever lock your keys inside and you have to damage may your vehicle to get in. Be sure you have extra keys.