Sign usages describe objects which represent other objects or which call attention to something. These include various forms of media, including texts, sounds, pictures, and graphics. As usages these are commonly applied to very specific objects like signs, logos, or flags.

The sign communicates beyond its physical presence. Sound can perform this function as well as visible lettering or pictures, so a sign need not be a printed board.

Labeling identifies something nearby, while advertisement promotes something apart from the sign itself. The particular message and its relation to its subject distinguish these uses.