BACK TO THE STANDARD EXPLANATIONS
The standard provides:
HAIR: The coat is harsh, dense and straight. The undercoat is dense and soft. With the exception of the head and the front part of the limbs where the coat is short and flat, the coat, of moderate length, is abundant all over the body. On the neck, the back of the limbs and the tail, the coat is longer - profuse coat on these parts being typical.