> […] because the word “not” could be added to any assertion, that one could say anything in
language – that is: language didn’t **contain** what was actually going on in the universe. -- Alan Kay. pdf 
⇒ The Center of “Why?”
The term code indicates a “Duplication Rule” which allows the correlation of every entity within its area of observation with a corresponding entity within the system.
> This applies in the first instance to the code of Language which allows the correlation of every positive formulation with a corresponding negative formulation. That is, the positive statement “it will rain today” can be understood as the negation of the negative statement “it will not rain today.” With language at their base, this also holds for the codes of different functional systems [→Differentiation of Society], which are always based on a binary schematization.
DOT FROM two-level-diagram
The interesting hypothesis is that freedom comes from duplication of systems from determinacy. ⇒ Duplication Rule
> They must be more than one system, and they must be complexity inferior, that is, they must not have *requisite varity* [sic!].