
As ridgieback says, it's the Breed Records Supplement - for those who don't know, this is the Kennel Club's quarterly publication which lists all registrations, transfers of ownership (and changes of name), imports, exports, major awards (CCs, Champion titles, JWs) and all health results (hips, elbows, eyes and probably others besides for different breeds?).
It is published in the showing 'groups' and makes very interesting reading - includes things like how many litters a bitch has had, what age she is, when she had her last litter, etc. and shows who really sticks by their breed clubs' codes of ethics at times! ;)
M.