As Iravatham Mahadevan points out, archaeological evidence makes it inconceivable that IVC's large, well-administered and sophisticated trading society would have functioned without effective long-distance communication. Unlike the clay tablets of Mesopotamia, no written records were discovered from Indus Valley sites except seals. The people of IVC might have written on cotton cloth, leaves, bark or hide which would have decayed by now, leaving no trace.
Questions about inscriptions, pictographs, and the written communication system used by the ancient Indus Valley civilization as well as attempts to decode it.