Mediaglyphs
From the Quicksilver Metaweb.
Stephensonia
*"What are those?" Nell said.
"Mediaglyphics," Harv said coolly. "Someday you'll learn how to read."
Nell could already read some of them.
"Red or blue?" Harv asked magnanimously.
"Red"
Harv gave it an especially dramatic poke, and then a new mediaglyphic came up, a white circle with a narrow green wedge at the top. The wedge got wider and wider. The M.C. played a little tune that meant you were supposed to wait.*
Definition
Mediaglyphics are a form of communication in Neal Stephenson's The Diamond Age. They consist of small, often animated symbols on a mediatronic surface. Mediaglyphs are a highly specialised form of language, and just as you wouldn't write a grocery list in Tolkien's Elvish, you would not use Mediaglyphs to compose a poem or write anything other than the simplest correspondence. Rather, they seem to be a continuance of the modern tendency to use symbols to convey large amounts of information in a small space.
For example: A sign consisting of a cigarette surrounded by a circle with a line crossing it is a very clear and consise "No smoking near this sign". Mediaglyphs would be invaluable for use in matter compiler menus, where a designer/engineer can convey such concepts as "Food category" and "Tools category" simply and in a very small space using animated mediaglyphs.
In the novel, Nell is depicted as writing letters to her brother Harv, "written simply using mediaglyphs". Mediglyphs therefore can be used to convey thoughts, ideas and states of being, but the message would be concise and simple, perhaps with a seperate set of glyphs used solely for conversation and exposition. Such glyhps would move on smart paper and are presumably in colour, so that the phrase "I ate a red apple" might only consist of two glyphs, the expositional one for "eating (past tense)", and a red-coloured one meaning "apple". Obviously, one wouldn't use such a system for detailed conversations, nor for scientific or academic work, but would allow Nell to keep in touch with her illiterate Thete brother.