A quick little gift by an incredible artist on Facebook called cherrytopsarts. A great artist and friend, you all should definitely check her out.

The markings on the stallions and mares on the continent of Equeria are very unique. They are neither tattoos or paint, but rather, part of the equines themselves. They are very clear sign of the species' connection to the magic imbued in their homeland. All equines are born with them. The markings usually grant an equine abilities when activated, usually in moments of stress, passion, or danger. True lovers will share a mixture of each other's markings. If an equine has a lover/lovers that do not have markings, their markings will simply appear on their bodies. A unique marking is documented to appear over the bellies of females once pregnancy is assured. The origin of the markings is a mystery, but to the equines of Equeria, it has simply been a normal part of their biology since the dawn of time. No doubt there are deep secrets connecting the markings, the equines, and the magic in their continent.