According to Chapter 7, a genuine symbol is one which actively and experientially connects an idea (or First) with some thing, event or fact (or Second), so that its Interpretant inhabits a more well-informed system. Peirce sometimes says that the symbol, ‘defined as a sign which is fit to serve as such simply because it will be so interpreted’ (EP2:307), is the ‘genuine sign,’ while the index is ‘degenerate’ and the icon doubly so (EP2:306). But he also sometimes distinguishes between genuine and degenerate symbols. In any case, the information conveyed by a symbol depends on the involvement of both icons and index in it.
A Symbol is a law, or regularity of the indefinite future. Its Interpretant must be of the same description; and so must be also the complete immediate Object, or meaning. But a law necessarily governs, or “is embodied in” individuals, and prescribes some of their qualities. Consequently, a constituent of a Symbol may be an Index, and a constituent may be an Icon. A man walking with a child points his arm up into the air and says, “There is a balloon.” The pointing arm is an essential part of the Symbol without which the latter would convey no information. But if the child asks, “What is a balloon,” and the man replies, “It is something like a great big soap bubble,” he makes the image a part of the Symbol. Thus, while the complete Object of a Symbol, that is to say, its meaning, is of the nature of a law, it must denote an individual, and must signify a character. A genuine Symbol is a Symbol that has a general meaning. There are two kinds of degenerate Symbols, the Singular Symbol whose Object is an existent individual, and which signifies only such characters as that individual may realize; and the Abstract Symbol, whose only Object is a character.— Peirce (EP2:274-5)