1) I guess if the vis is that bad, the airfield will be operating 'low vis' in which case mid and stop-end RVRs (if available) will be given?
2) The only 'controllling' mid-point RVR I am aware of (CatI) is 75m or less, and same for stop-end, but ONLY if the latter is specified in the
Company Ops manual - which it ain't