Curious about pure bred

How can 2 different types of dogs be labelled as a purebred? And how can CKC or others label them as purebreds?

I thought that the male and female had to be of the same breed.

They do have to be the same breed, and registered with the AKC/CKC

CAn you give an example of what you are talking about?

I was reading Thaighing post about her dog. Oops was reading it again, was confused. :o