When the AKC cracked down on breeders, many had to leave and these alternative registries popped up. Some of them took legitimate sounding names and even used the initials of other legitimate clubs, for example the Canadian Kennel Club is the AKC equivalent in Canada. However, the other CKC is the Continental Kennel Club, and they will register dogs that aren't eligible for AKC, as well as mixed breeds. The AKC is the only registry that does routine unannounced inspections as well as DNA testing. This is not to say that all breeders with the AKC are good, but that the AKC is trying to get rid of the ones that are the worst. For more information on the different registries see:
Registries