 The rules for the permissible combinations are actually quite simple so long as we bear two things in mind. First, types of each element are classifiable as either a quality, an existential fact, or a convention. That is, across the three elements of a sign, there are three types deriving from qualities (the qualisign, the icon, and the rheme), three deriving from existential facts, (the sinsign, the index, and the dicent), and three deriving from conventions (the legisign, the symbol, and the delome). Second, the classification of the interpretant depends upon the classification of the object, which in turn depends upon the classification of the sign-vehicle. The rules that determine permissible classifications, then, are that if an element is classified as a quality, then its dependent element may only be a classified as a quality. If an element is classified as an existential fact, then its dependent element may be classified as either an existential fact, or a quality. And if an element is classified as a convention, then its dependent element may be classified as either a convention, an existential fact, or a quality. This leaves us with ten permissible combinations between a sign-vehicle, object and interpretant, and so ten possible kinds of signs. They look something like this: