How do you identify a Black Back dog?

A Black Back usually means a black-backed, yellow-bellied German Shepherd with a large, vivid black patch on the back and yellow fur on the belly, head and limbs, plus some black flecks. A pure Black Back has smooth body lines, balanced proportions and bold but not clumsy head and limbs. Males stand about 24 to 26 inches, females about 22 to 24, with chest depth 45 to 48 percent of height and body length 110 to 117 percent.

Also, a pure Black Back has almond-shaped, slightly slanted, deep-colored eyes that do not protrude, with a sharp, calm expression.