Normally it would be assessed at a breed seminar. I would hope all breed clubs require an assessment before putting a judge on their A list to award CC's! I thought there was a rule a judge had to go on the C then B list first if they did not award tickets in any other breed at all, you can go directly onto the B list however if the club deems your breed knowledge is sufficient. However there is nothing in the red book about judges training. This which is an advisory document which does say judges HAVE to first be on a breed club list (B) to judge at least 3 classes at open show level...so according to this they must work their way up and cannot go straight onto an A list. The A list criteria requires judges to have judged at open level, have judged xxx number of dogs, and so on before being admitted to an A list to award CC's. If a judge is NOT on any breed club list (C / B) they cannot judge at limit and open shows. The exception would be a foreign judge...one who is maybe Irish who already awards Green Stars and then yes they get put straight on some club lists to award CC's here without going through the criteria UK based judge would have to despite the fact that in Ireland to award Green Stars there are some judges who have never laid a finger on a breed until it is in from of them in the ring.
http://www.thekennelclub.org.uk/media/101071/advisorycriteria.pdfAs I have found out recently the KC has absolutely no rules at all on how individual breed clubs are run, nor are they interested if a breed club breaks it's own rules and code of ethics. I had a complaint about a breed club and the KC said it is up to breed clubs to make their own rules and regulations individually and the KC cannot and will not bring action against a club that breaks it's own rules. So it seems if you know of a case of a breed club putting someone straight onto their A list to award CC's for the first time in any breed without ever having worked their way through a c and/or b list to get numbers for experience and prove their ability to judge at open show level and write critiques then yet again the KC are shown to be pretty worthless. The only stipulation the KC do enforce is that judges must have done the specific KC seminars before awarding CC's on conformation and movement, and show regulations...what a farce.