RVR reports reach aircraft via ATS units and / or aeronautical broadcasts.
Flight Crew Reference Guide

a. The reporting scale should consist of increments between 25 metres, when RVR is less than 150 m, 50 metres for RVR up to 800 metres, 100 metres for RVR between 800 and 1200 m and increments of 200 m for RVR above 1200 m. Where the observations are made by counting runway edge lights, the reporting increments should be determined by the spacing of those lights. Any observed value which does not fit the reporting scale in use should be rounded down to the next lower step in the scale.
b. 50 metres should be considered as the lower limit for measurements and reports of RVR.
Below this limit the reports should merely indicate that the RVR is less than 50 metres, in the form ’RVR BLW 50 m’.
c. RVR should be reported to the appropriate local ATS units, whenever there is a change in the value to be reported in accordance with the reporting scale. The transmission of such reports should normally be completed within 15 seconds after the termination of the observation.
d. In reports in abbreviated plain language the name of the element should be given in abbreviated form and the units should be included, for example, ’RVR 400 m’.
When RVR is above the maximum value which can be determined by the system in use, it should be reported in the form ’RVR ABOVE 1700 m’; the use of this form of reporting should be limited to cases where RVR is above a value between 1500 m and 2000 m.
When the RVR is below the minimum value which can be determined by the system in use, it should be reported for example in the form ’RVR BLW 150 m’ where the figure 150 is the minimum value that can be determined by that system.
If RVR is observed from one location along the runway, about 300 metres from the threshold, it should be included without any indication of location. If the runway visual range is observed from more than one location along the runway, the value representative of the touch down zone should be given first, followed by the values for the other locations along the runway, together with an indication of these locations, according to the method by which positions are notified in the Aeronautical Information Publication (AIP), for example, ’RVR RWY 16 PSN A 600 M PSN B 500 M PSN C 400 M’. When there is more than one runway in use, the available RVR values for each runway should be given and the runways to which the values refer should be indicated, for example, ’RWY 26 RVR 500 M RWY 20 RVR 800 M’; if more than one runway is in use, but RVR is available only for one runway, that runway should be indicated in the form ’RWY 20 RVR 500 M’.
e. In reports disseminated beyond the aerodrome only the value representative of the touch down zone should be given and no indication of location on the runway should be included. When there is more than one runway in use and there are significant differences in RVR between those runways, values for more than one runway should be included in accordance with agreement between the authorities and the operators concerned and the runways to which the values refer should be indicated in the form ’RWY 26 RVR 500 M RWY 20 RVR 800 M’.
f. At an aerodrome with several runways used simultaneously for landing and take-off, the RVR should be computed separately for each runway: these computations should be based on the runway light intensities currently used for each runway. When one or more of the runways are temporarily out of use, the RVR for these runways should be computed on the basis of the light intensity currently used for the runway or runways in service or, the highest light intensity currently being used for any of the runways in service, if the intensities are different. When all runway lights are switches OFF, the RVR should be computed on the basis of the appropriate light intensity which would normally be used.
Source: FCRG
See also:
1. Horizontal visibility aspects
2. Visual range
3. Observing techniques of RVR
4. Observing of RVR
5. Availability of RVR observations at ATS units
6. Reporting procedures of RVR reports
7. Accuracy of RVR reports
8. Slant visual range
9. The visual segment
10. Variation in visual segment
11. Flight visibility and vision at high altitudes