Chevrolet 1998 Prizm Owner's Manual page 81

Both keys are used for
the ignition, the doors
and all other locks.
When a new vehicle is delivered, the dealer removes
the metal plate from the key ring and gives it to the
first owner.
The metal plate has a code on it that tells your dealer or
a qualified locksmith how to make extra keys. Keep the
code in a safe place. If you lose your key, you'll be able
to have a new one made easily using this code.
NOTICE:
Your vehicle has a number of features that can
help prevent theft. However, you can have a lot o
trouble getting into your vehicle if you ever lock
your key inside. You may even have to damage
your vehicle to get in. So be sure you have an
extra key.
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