The glyph system of the Rhymar Trilogy in it's entirity. It was created more for the illustrations, rather than playing a crucial part in the books. But, most of the creatures in the world use it, since a more refined letter system was lost in the apocalypse. In fact, only one country in the world is literate; everyone else is stuck with pictograms. They're universal, though, so that's a perk.