of these articles describes transmission regulations. For further meanings, see code (term clarifying).

Under a code or a code /ko: t/is understood a regulation, in which symbols of a representation will transfer into such another. For example the Morse code placesa transmission regulation between letters and a succession of short and long sound signals ago. Generally linguistic usage understands one by a code usually a kept secret code, which is used for the coding of messages. A code can from data, numbers, indication, letter orother storage mediums consist, but for example also of DNS strands.

Generally codes are however simple an agreement between noting and reading, in order to establish an efficient production way for frequent messages. They serve the low-power or also safe recording andTransmission of information. In addition in place of the information simpler elements and combinations of these are used. These combinations refer to the original information. The more frequently something is used, the smaller should the expenditure for the processing of an element be.

Codes contain two aspects of efficiency:

  • On the one hand they replace the original by a pure reference to this (the designated is replaced by the code word) and to need therefore only one supply on references, which guarantees recognizing barness and distinction (mistake liberty).
  • Secondly they mostly use a building block principle, as more frequent of references are made available by longer (vielelementige) combinations by short (wenigelementige) combinations and rarer of references. Thus the simplest elements (elements, indications) are as frequently as possible used and/or. reused (in nearly all references).

Codes are seen within a larger framework, independently of their own Raffinesse, only by the repeated use than aids to the information transfer really efficiently. Because the comprehensibility with the reading system sets also into this any preparingOrganization (z. B. Learn) ahead. Codes become therefore a component of culture of systems (e.g. ) And a certain Beharrlicheit develops national language, technical standards against changes. The energy minimization makes codes attractive for the information transfer under special conditions: large distances, large time intervals, large receiver number, transmission at minimum expenditure in emergency situations, transmission with the help of other systems, which work in this energy and structure dynamic range.


  • The use of references is efficient. Also within other ranges, like e.g. Simulation.
  • ThoseUse of a building block principle is efficient, if thereby the use of frequent simple elements is promoted.
  • Effects can take place also very indirectly (mediated over a long chain).

NIC-read Luhmann uses the term code as name for standardized differences. (Guidance difference)

table of contents

examples of codes


a code can be so developed that the result codes, into it information, redundant, thus redundant portions contains. That is, the produced succession of Symbols contains data, which do not lead to the goal and if one decodes them wrongly, a wrong result devoted.

In the simplest case the same is again repeated. But each increased predictableness of indications is redundancy: So e.g. are. the us after q s in the writing German everything redundantly, since after a q always follows a u. It would be lost thus to no information, if all were removed on a q the following u s. The redundancy helps one however, important information despitea partial overrun still decipher and to use to be able. It protects thus against information loss. Besides it permits to recognize falsified information as such. In the technology these redundancies are produced purposefully by means of procedures of the channel coding. Also in the information transfer(e.g. Infrared instructions for television sets) are used codes. For example the RC5-Code.

see also:

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