What does pk3 mean in your 2000 Buick park avenue key?

In the context of your 2000 Buick Park Avenue key, "PK3" refers to a type of anti-theft system known as the Passkey III. This system uses a transponder chip embedded in the key, which communicates with the vehicle's ignition to ensure that only the correct key can start the engine. If a non-compatible key is used, the vehicle's security system will prevent it from starting, enhancing overall security against theft.