This is a very interesting thread on a very interesting subject and I really appreciate that everyone is asking questions and giving answers so nicely..sometimes this subject gets a bit out of hand and the information that people would like to hear gets lost in the shuffle..
Splitters (Yorkie/Biewer breedings) can be registered in Germany. I am in the process of registering a litter now. This litter is two females that look totally like Yorkies (F1) Now, next time, when I breed one of these girls with a full Biewer, I should (?) have a litter where some of the pups will look like Biewers and some will look like Yorkies. I have not done so previously, but I have been told that when I register these puppies, the ones that look like Biewers will be registered as Biewers and the ones that look like Yorkies will be registered as Yorkies.(in Germany) Neither of the two clubs I work with here in the states will register my splitter female puppies but that's OK with me as I will have them registered in Germany. All of my breeding Biewers are German registered and I will just continue to register my breeding dogs that way..
-Diana
This is the first time I have bred the "splitters" so this information is just based on research not on to much personal experience yet so I'm open if someone has something to add.