What defines a coronet leg marking?

A coronet leg marking is characterized as a narrow white marking that appears at the top of the hoof, specifically around the coronet band, which is the area where the hoof wall meets the fur. This marking is generally quite small and distinct, typically appearing as a thin strip of white that follows the contour of the coronet. The position and size of this marking make it easy to identify and differentiate from larger or more extensive leg markings.

The other options describe markings that do not correspond to the specific characteristics of a coronet leg marking. For example, a marking that covers the entire leg would be classified differently, as would markings that are limited to the ankle or stretch down to the knee. Each of these options represents a different kind of leg marking, illustrating the variety of white markings horses can have but not accurately capturing the definition of a coronet marking.