YMMV = Your milage is controlled by law, and cannot vary.

You can sign broken contract freely - it's unenforceable, so you can sign whatever paper HR hands to you, and only when you're retaliated against do you need to care. Which coincidentally is when you stop needing to be cooperative anyways.

Don't "YMMV" your way out of laws that protect you.

Some contract clause meanings have physical location dependence on where they are signed. That is why one should always consult local legal representation as well. =3