Originally Posted by
captjns
ICAO (a United Nations Agency) Annex 6 to the Convention on International Civil Aviation, Part 1 states in
paragraph 4.4.1.2:
"An instrument approach shall not be continued below 300 m (1 000 ft) above the aerodrome elevation or into the final approach segment unless the reported visibility or controlling RVR* is at or above the aerodrome operating minima."
Refer to the country's specifics of operations Aeronautical Information Publication for differences in Approach Bans.
The following paragraph to that quoted above, 4.4.1.3, stipulates that (barring alteration by the State criteria), the procedure may be continued once inside the final approach segment (below 300m/1000') if the RVR falls below minimums. In this case, the procedure may be continued to MDA/DH, but is not authorized below (without appropriate visual references required at MDA/DH/DA).
4.4.1.3 If, after entering the final approach segment or after descending below 300 m (1 000 ft) above the aerodrome elevation, the reported visibility or controlling RVR falls below the specified minimum, the approach may be continued to DA/H or MDA/H. In any case, an aeroplane shall not continue its approach-to-land at any aerodrome beyond a point at which the limits of the operating minima specified for that aerodrome would be infringed.
Note.— Controlling RVR means the reported values of one or more RVR reporting locations (touchdown, mid-point and stop-end) used to determine whether operating minima are or are not met. Where RVR is used, the controlling RVR is the touchdown RVR, unless otherwise specified by State criteria.
http://www.smolenskiefakty.com/icao_annex_6_part_1_section_4_4.pdf
The crucial element at arrival at minimums continues to be not if meteorological reported minimums are at or above charted minimums, but whether one has the necessary references to continue the procedure below minimums; it comes down to whether one can see the approach or runway lights to either continue, or land.