In 1936, Rottweilers were exhibited in Britain at Crufts. In 1966, a separate register was opened for the breed. In fact, in the mid-1990s, the popularity of the Rottweiler reached an all-time high with it being the most registered dog by the American Kennel Club. The Rottweiler nose is well developed, more broad than round, with relatively large nostrils and always black. The muzzle should appear neither elongated nor shortened in relation to the cranial region. The color and markings of a Rottweiler are very distinctive.