
DLC stands for Dog Lovers Club, which means absolutely nothing, and has nothing whatsoever to do with the Kennel Club!
Basically, people can make up any 'facts' about a dog's parentage that they want, and the DLC will send them a printed certificate with these details on it. No verification or anything. The parent dogs don't even have to be of the same breed.
It seems to be that if the pups are 'Registered' then they can be sold for more money, and for your extra £100 you get a worthless piece of paper.