Thank you red-eye.
So the conculsion that can be drawn from a metar showing 9999 vis, NSC and no indication of percipitation, rather than CAVOK, is that one of the following must (should) exist:
A) Shallow fog (but must be more than 10km from the airport) or reduced vis in one direction should be reported.
B) A forecast that might change one of the previous factors.
Thank you for helping to increase my understanding!
dp