Sometimes one would need an outcross to get a larger gene pool as the Nebelung is still a young breed, and there is a risk of the prosentage of inbreed getting higher than wanted. To work against this one would bring in a permitted outcross.
For the Nebelung breed the only outcross permitted is the Russian Blue.
Longhaired kittens would be a Nebelung, Shorthaired kittens would be a Nebelung variant.