The Yorkshire Terrier (often called simply the Yorkie) is a breed of small dog in the terrier category. The long-haired terrier is known for its playful demeanor and distinctive blue and tan coat. Yorkies can be very small, usually weighing not more than 7 pounds (3.18 kg); the standard of this breed does not mention the minimum weight accepted nor does it specify a height. Based on registrations of the American Kennel Club, Yorkshire Terriers became the second most popular dog breed in the United States in 2006, trailing only the Labrador Retriever.