Forgive me if this doesn't belong here, but I thought this more appropriate for PM than for Programmers or SO.
We use risk assessments where I work as part of the software development life-cycle. A matrix of impact (sometimes referred to as severity) versus likelihood is used to establish absolute risk. One of the levels of impact (or severity) is "None" which I take to mean 'if this happened there would be absolutely no impact'.
Have I missed something? I've asked colleagues but no one seems to be able to come up with a meaningful answer. What is the point of defining a risk which has no impact? Surely that is not a "risk" that is just 'something which can happen' and has no business on a risk assessment.