This has been discussed during various IFR courses and refreshers.. I'm
running on old memory here.
For a Part 91 operation it is not enforceable. The tower has no way of
knowing what the pilots in-flight visibility is at the approach end of the
runway.
I have seen pure VFR on one end for 2,000ft of a 10,000 ft runway.. with the
other parts of the airport the fog so thick you could not see the lines to
taxi.

For Part 135 and other operations, the pilot cannot even begin the approach
for a "look see" if the visibility and ceiling are reported as less than
that required for the approach.

Now whether ATC reports it or not?

BT

"Robert M. Gary" wrote in message
...
This is from my FIRC study guide....

"It is still true, however, that ATC is required to report to an FAA
district office as an incident, any landing that is made when the
visibility is being reported as less than one- half mile, or the RVR
is less than the published minimums. And the pilot may be asked to
explain to the FAA the circumstances of the landing."

Sounds wrong to me.

-Robert