The sign fulfills the function of conventionally expressing abstractions for the purpose of operating in the world, unifying phenomena that are distinct in nature in one same level of language. Expression and meaning are a structure. When the meaning of an expression is unknown, the sign loses operative value. Equivocal or multi-vocal expressions are those that allow various meanings, and their comprehension arises by context. The context gives uniformity to the level of language. But contexts are usually placed outside the ambit of a given level of language, giving rise to syncategorematic or occasional expressions. For example, in front of the same instance of a knock at the door, when someone asks, “Who is it?” different people answer, “Me”—and in each case it’s understood who it is by the voice, the time of day, a visitor’s expected arrival, etc. In other words, through contexts that are outside the level of language in which what is always said is: “Me”. As for the sign as such, it may be the expression of a meaning, or it may fulfill the function of indicating another entity through its associative character.
Differences between Signs and Signical Categories
The connectives between signs are formalizations of relationships, such connectives being, in turn, signs. When signs lose their meaning due to a cultural shift, they are usually considered as symbols.