The professional competitiveness of the modern man is largely based on literacy in its widest sense, including the ability to read any text: verbal and nonverbal, continuous and discontinuous. Yet the perception and interpretation of the messages exchanged between sender and receiver is only adequate if both use the same sign system. It is these contextual signs that are the basis of functional literacy, which consists of a number of other literacies: general, informational, foreign language communication, digital, daily life problem solving, acting in critical situations, communication, legal, and social-political literacy. The right time for the development of functional literacy is the gymnasium stage. However, since no single school subject is capable of achieving it alone, what we need is a complex transdisciplinary strategy to this end.