They all use Kinagrams—a moving picture script. Very few are literate. Well-off burgers typically can read and write, but lots of the workers and virtually all the slines can't read.
Aren't Kinagrams and Logotype Arban forms of logograms, like Chinese characters or Kanji? I interpreted that as "most extramuros can read and type their daily language, but not the alphabet used for technical writing"
The extramuros language is “Fluccish” and it’s stated that it uses the same alphabet as Orth. I think it’s a little more pictorial (esp. Kinagrams with animation) than Chinese