This is a piece from the post on yorkie markings:
"There may be a white star or a small blaze located on the fore chest in the tan, or across the black and tan. This is a much looked-for point, as it is an indication that the puppy will probably be a good coat grower in quantity, though not necessarily in quality. It is also an indication that there will be no melanism, or over-supply of pigment. "
Here is the link to that post:
http://www.yorkietalk.com/forums/gen...rt-thread.html
You can also find that info on the YTCA site and you might want to print that information for anyone with questions.