i've never heard of them, i got Google at
http://www.puppypetite.com/yorkies.html
Puppy Petite. He came home with a kennel cough and a cold. If I knew then what I know now I woukd have tried to find a breeder first, but I love my lil' Google. He's almost 7 months old now, and outside of his not losing his baby teeth he is a healthy pup.
When they sold him to me he just turned 8 weeks old, and already had his dew claws removed and his tail docked. I wouldn't have done that, myself, I would have rather had him 'all-natural.'