Strongly built, and compact yet elegant, Andalusians have long, thick manes and tails. Their most common coat color is gray, although they can be found in many other colors. They are known for their intelligence, sensitivity and docility. A sub-strain within the breed known as the Carthusian, is considered by breeders to be the purest strain of Andalusian, though there is no genetic evidence for this claim. The strain is still considered separate from the main breed however, and is preferred by breeders because buyers pay more for horses of Carthusian bloodlines. There are several competing registries keeping records of horses designated as Andalusian or PRE, but they differ on their definition of the Andalusian and PRE, the purity of various strains of the breed, and the legalities of stud book ownership. At least one lawsuit is in progress as of 2011, to determine the ownership of the Spanish PRE stud book (Wikipedia).