"Phantom Spots" could also be called phantom roaning, selective roaning, reverse calico, or vanishing roan
When roan and pinto genes (tobiano, tovero, and manchado specific) interact, it is possible for the roaning to become selective, appearing only on a few spots on the main body of the horse. It's important to note that the presence of the roan gene is necessary for these phantom spots to appear, and they will not be present on the lower legs and head of the horse.
Phantom spots can vary in size, with some taking up to 3/4 of the horse's pinto spots, although it is more common for them to affect up to 1/2 of the spots. Additionally, the roan gene can cause more extensive mapping on all of the pinto spots. The color of the phantom spots can range from nearly white to nearly the base color, as long as there is some distinction between the main body color and the roaning.