Rottweiler how to see pure or impure

How to see if a Rottweiler is pure or not? The purebred Rottweiler male is about 63-69 cm tall at the shoulder and the female is about 58-63 cm tall at the shoulder; the Rottweiler coat is short and smooth, black in color with fawn or reddish-brown spots, the proportion of spots does not exceed one tenth; the head is of medium length, moderate in size, and slightly wrinkled on the forehead. Height: The male dog is about 63-69 cm tall at the shoulder, and the female dog is about 58-63 cm tall at the shoulder. Coat: The coat is short, straight and coarse on top and fine on the bottom. The coat is black, with fawn or reddish-brown spots on specific areas, which do not exceed one-tenth of the body. The undercoat is black, gray, light brown, but it is not good if it is visible from the outside. Curly hairs are considered unsatisfactory. Head: Medium length, wide skull cap, short and thick nasal muzzle, fairly elevated forehead, both foreheads very expansive, and dogs with wrinkled heads. The head is of medium length, wide between the ears; the forehead is moderately arched; the cheekbones are arched and the stop is clear, and the upper and lower jaws are very strong. The forehead is dry, but when it is alert, some wrinkles appear. The expression is noble, alert and confident. Ears: Medium sized ears with a high root and flat lying position. Drooping, triangular; the ears are in the same plane as the top of the head when listening vigilantly, giving the head a broadened appearance. The ears are relatively far apart and drooping, with the inner edge of the ear close to the head and the end near the middle of the cheek. Eyes: Apricot kernel eyes, medium in size and bronze in color. Nose: The nose is very well developed and must be black. Torso: Four-sided body, firm and strong, with a broad chest, straight back and sloping loin. Limbs: straight, muscular front limbs, hind limbs bent at an acute angle. Feet: firm feet, rounded forefeet, slightly elongated hindfeet, hard fleshy toes, short and black claws, bulging toes, and popular toenails that resemble marks painted on with a black pencil in front. Tail: The tail root is high and horizontal, and the tail is usually broken at the first joint.