More info here:

http://www.thecavalierclub.co.uk/hea.../clearmri.html

Any dogs wordwide which have MRId clear can be included regardless of whether they are registered; you need to submit a neurologist's certificate or report for verification. They just made the announcement and are accepting applications for the list. No charge -- this is similar to the MVD-clear list they maintain. With luck the US clubs might start such a scheme too.