About wrapping, imagine when your yorkie hair getting longer, when playing outdoor, yorkie's hair might get dirts and sometimes broken. So to keep yorkie hair in good condition just like a show dog, wrapping must be applied. Also wrapping is technique that is normally used by exhibitors to aid in growing a long show coat. If you search through yahoo or google finding about yorkie wrapping, you will see many website that teach you how to wrap your yorkie hair. Here is one example,
http://www.geocities.com/Heartland/Ridge/6636/help.html