What exactly happens if you break a three month resignation period? I don’t advocate doing this in generally but as a hypothetical exercise if this person just stopped showing up for work, what exactly could the company do?
Was curious about that as well. I've never heard of such an obsurd amount of time, and it seems doubtful it would hold up. "You need to give us 3 months heads up no matter what, but don't worry, we don't have to give you any if you oversleep for a meeting."
But this is for when both of them can't find a mutual solution. You can always agree to terminate the contract earlier, if both parties agree.
At least that is how it works in Germany.