Code

A code is simply an unvarying rule for replacing a piece of information (e.g., a [delete this word letter], word, or phrase) with another object or action, not necessarily of the same sort. One reason this is done is to enable communication in places where normal methods of language use aren't possible. For example, the use of [semaphore flags]? replaces each letter of the alphabet with a configuration of flags held by a signaller or the arms of a semaphore tower; it is not a code. Another person standing a great distance away can interpret the flags and reproduce the letters, enabling the signaller to communicate with someone too far away to hear ordinary speech. Morse code allows communication over telegraph wires, flashing lights, or other channels that cannot carry speech or text; there, Morse code operates at a purely syntactic level and is thus not a code, but it is also not intended to provide privacy, preventing all without the codebook from understanding the transmission. A code operates on semantic levels of a message, replacing something having meaning with something else. Since the first undersea cables were installed, and until radio replace them, elaborate commercial codes that encoded complete phrases into single words (five-letter groups) were developed, so that telegraphers became conversant with such "words" as BYOXO ("Are you trying to crawl out of it?"), LIOUY ("Why do you not answer my question?"), and AYYLU ("Not clearly coded, repeat more clearly."). The purpose of these 'non-confidential' codes was to save on cable costs.

Another use of codes is cryptography, whereby a codebook is used to control semantic substitution, preventing those without a codebook from understanding the transmission. This should be contrasted with 'cypher?' which also prevents understanding by replacing syntactic elelments (eg, letters) with something else. These are not codes.

Probably the most widely known code in use today is ASCII; it is more correctly referred to as a 'representational assignment list'. Secrecy is not an intent in ASCII, and if it were, ASCII would be a cypher in any case. It is employed by nearly all personal computers, terminal?s, printers, and other communication equipment. It represents 128 characters with seven-bit binary numbers - i.e., as a string of seven 1s and 0s. In ASCII a lowercase "a" is always 1100001, an uppercase "A" always 1000001, and so on. Extensions to ASCII have included 8-bit characters (non-Latin letters and such things as card suit symbols), and in fullest flowering have included glyphs from essentially all of the world's writing systems - Unicode.

Acronyms and abbreviations can be considered codes, and in a sense all languages and writing systems are codes for human thoughts. Occasionally a code word achieves an independent existence (and meaning) while the original equivalent phrase is forgotten or at least no longer has the precise meaning attributed to the code word. For example, the number "86" was once used as a code word in restaurants meaning "We're out of the requested item". It is now commonly used to mean the removal or destruction of something.

The word code is also used to refer to the result of computer programming; this use of the word has not yet passed from jargon into general vocabulary, however. In this usage, "code" typically stands for "source code", and "to code" means "to write source code, to program". This usage is socially marked; identifies its user as an "insider" in computer programming.

The word is also used to refered to rules or laws such as in code of honor, municipal code, traffic code, dress code, penal code etc.

This word has acquired a large number of subtly and grossly incompatible meanings. Use with care.

see also morse code, country codes