Just for interest, in Canada we have an approach ban. While not providing the exact quote the gyst of the regulation is: refering to CAT 1 approaches only, an aircraft may not proceed beyond the FAF with an RVR of less than 1200 (ft) unless it is a training flight and there is no intention to land. There is no spiel given to the crew, they are just advised of the current RVR with the expectation that the crew should be aware of what is stated in the CARs. If the RVR should go below 1200 after the a/c has gone by the FAF it is up to the crew to determine the course of action.