[Mongo]

Frontierrots,
You are right I was unable to remember which registry it was, (This was learned with Hunting dogs, which had usually four to five different sets of papers on the same dog) they seem to come and go and different breeds have different registrys.
But in the day twenty to twenty five years ago, once you had purple ribbon papers on both dogs and you went closer than the six generation span they kicked you back to the yellow papers.
In other words line breeding is or was defined by that six generation skip before you breed straight back, any thing closer is Inbreed.
This is the method that has been used to develop different newer breeds and or to re coupe almost lost breeds and or species that still have a large numbers of stock to breed from.
This is not the thing that any average person is or should do. It is for the ones that are completely devoted for life to a breed and or species. For as poohbearsmom stated one MUST be willing to cull or one should not breed, neutering and or spaying is now the norm instead of the old school CULL.