ansys

Hi all, This has been bugging me for a while now. While repairing my 2nd gen (1996) JDM Subaru Legacy's ignition lock cylinder, I came across this little nub. I can't for the life of me figure out what it does though. It's located on the bottom of the ignition cylinder lock, and there's even a cut-out for it in the plastic housing under the steering column so you can access it without taking anything apart. Anyone have any idea as to what it's purpose is? Cheers!