If you are interested in the Bearded Collie breed you may wish to read about merles. The six British Bearded Collie Clubs object to the Kennel Club allowing the registration of Merles - if you want to know why then see the press statement - link above.
At this very moment no merles have been registered in the UK so puchasing a Bearded Collie registered with the Kennel Club still avoids this problem. If you are concerned ask your breeder to reassure you - if you want to speak to those who would register Merles by all means do so.
I do not think nor have I seen any evidence which suggests allowing the registration of Merles will be of any benefit to the health and well being of the breed.
