There is something about the phrase Non Functional Requirements that I don’t really like. It’s the Non bit which gets me - I think that word makes them feel unimportant and therefore there is no pressing need to explore how they will affect the system. I have seen on many projects teams procrastinating in defining how the “NFRs” will affect what they are building - usually in the metrics around performance.
On my current project we have decided to appease my sensibilities and have called these Cross Functional Requirements to better express what they truly represent - requirements which cross all the functions we are building. So far the wording works - but we have only finished the 2nd week of inception.