Just to add from a tactile design perspective, symbols and their recognisability continues to be a major issue. Partially, it is a matter of what can be sensory recognition. Touch has granularity issues so the number of symbols is delimited to avoid confusion. Partially, it is a matter of public recognition. Not enough people encounter coherent sets of tactile says symbols so there is no shared foundation of signs to build upon. Complexity cannot be created when there is neither enough symbols nor enough cycles of presentation design with new depth of meaning and a great weight replies of comprehension and acceptance.