The Commens Dictionary
Quote from ‘An Elementary Account of the Logic of Relatives’
Signs, or representations, are of three kinds: Icons, Indices, and Tokens. The token represents its object in consequence of a mental association, and depends upon a habit. Such signs are abstract and general, because habits are general rules to which the organism has become subjected. They are, for the most part, conventional and arbitrary. All common nouns are tokens. Indeed, all words, insofar as they are conventional, partake of this character.