A leg marking characterized by white color that extends almost to the knee is?

A leg marking that extends almost to the knee on a horse is referred to as a stocking. This specific type of leg marking typically features a significant amount of white that covers the lower leg and can extend up to the knee or even slightly higher. Stockings are commonly associated with certain breeds and are often seen as a desired marking in show horses, as they add to the horse's visual appeal.

In contrast, fetlocks are markings that are located around the ankle area of the horse, while a blaze is a narrow white stripe that runs down the front of the face, and coronet refers to a small white marking that encircles the top of the hoof. Each of these markings has its distinct characteristics, making the definition of a stocking unique in the context of leg markings.