A Parti Yorkshire Terrier has white spotted patterns with any of the colors/color patterns described here.  Parti originates from a recessive piebald  gene, so both parents must at least carry Parti to produce Parti pups.  The amount of white also tends to be “dose dependent” in Yorkies, i.e., If a dog only carries on piebald gene, it will generally have white on the chest and maybe small amounts of white on the feet, neck, head, chin and occaisionally back.  If it has both piebald genes, there is generally white on all four legs, patches over back, head and tail.  In the Yorkie world, “terms get crazy” when add Parti…and move between American and European nomenclature