The rule is called transferred redundancy and it goes like this in the UK: the company can't eliminate a high level position if some argument can be made that they only needed to eliminate a lower level position. So if a company feels it doesn't need a certain VP position, it can't actually get rid of that VP position if there is some argument that the company would only need to get rid of a lower director position. And the director position can't be eliminated if there's some argument that only a lower senior position could be eliminated. And the senior position cannot be eliminated if there's some argument that only a junior position would need to be eliminated.