When you click the realisicic check box, it could spawn a dropdown window,where you could check the options.
Of course, in the server, instead of just "Realistic on" you would also have to have the separate components,
"Falling damage on!
"recoil on!"
Those two messages would mean that falling would hurt, and you have recoil, but you can still see people and health is normal, and thereare still bonuses (if the server allows)