It is more closely associated with the semiotics of Charles Peirce (1839–1914) than Ferdinand de Saussure (1857–1913) because meaning is conceived as an effect of a set of signs.
A list of sign types would include: writing, symbol, index, image, map, graph, diagram, etc.
Yet this stimulus cannot be divorced from the visual evidence of the speaker's manner and gestures, and the general awareness of the physical location and its possible connotative significance.
What type of paper is used, what colour ink, what kind of writing instrument: all such questions are relevant to an interpretation of the significance of what is represented.
Rhetorician Thomas Rosteck defined rhetoric as “the use of language and other symbolic systems to make sense of our experiences, construct our personal and collective identities, produce meaning, and prompt action in the world".