[philip1209]

My understanding isn't that it is a legally-binding contract, but that you basically trade positive reference checks should an employee leave in exchange for predictability in when they leave.

[walshemj]

So they are basically offering nothing no one sensible ever gives anything more as a reference than

"mr/ms x worked here from date to date"

For fear of some manger having rush of blood to the head and leave a company open to a law suit.

What's in it for the employee?