code

—coder, n. —codeless, adj.

/kohd/, n., v., coded, coding.

n.

1. a system for communication by telegraph, heliograph, etc., in which long and short sounds, light flashes, etc., are used to symbolize the content of a message: Morse code.

2. a system used for brevity or secrecy of communication, in which arbitrarily chosen words, letters, or symbols are assigned definite meanings.

3. any set of standards set forth and enforced by a local government agency for the protection of public safety, health, etc., as in the structural safety of buildings (building code), health requirements for plumbing, ventilation, etc. (sanitary or health code), and the specifications for fire escapes or exits (fire code).

4. a systematically arranged collection or compendium of laws, rules, or regulations.

5. any authoritative, general, systematic, and written statement of the legal rules and principles applicable in a given legal order to one or more broad areas of life.

6. a word, letter, number, or other symbol used in a code system to mark, represent, or identify something: The code on the label shows the date of manufacture.

7. Computers. the symbolic arrangement of statements or instructions in a computer program in which letters, digits, etc. are represented as binary numbers; the set of instructions in such a program: That program took 3000 lines of code. Cf. ASCII, object code, source code.

8. any system or collection of rules and regulations: a gentleman's code of behavior.

9. Med. a directive or alert to a hospital team assigned to emergency resuscitation of patients.

10. Genetics. See genetic code.

11. Ling.

a. the system of rules shared by the participants in an act of communication, making possible the transmission and interpretation of messages.

b. (in sociolinguistic theory) one of two distinct styles of language use that differ in degree of explicitness and are sometimes thought to be correlated with differences in social class. Cf. elaborated code, restricted code.

v.t.

12. to translate (a message) into a code; encode.

13. to arrange or enter (laws or statutes) in a code.

14. Computers. to translate (a program) into language that can be communicated to the computer.

v.i.

15. Genetics. to specify the amino acid sequence of a protein by the sequence of nucleotides comprising the gene for that protein: a gene that codes for the production of insulin.

[1275-1325; ME < AF, OF < L codex CODEX]

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I

System of symbols and rules used for expressing information according to an unvarying rule for replacing a piece of information from one system, such as a letter, word, or phrase, with an arbitrarily selected equivalent in another system.

Substitution ciphers are similar to codes except that the rule for replacing the information is known only to the transmitter and the intended recipient of the information. Binary code and other machine languages used in digital computers are examples of codes. Elaborate commercial codes were developed during the early 20th century (see Jean M.E. Baudot, Samuel F. B. Morse). In recent years more advanced codes have been developed to accommodate computer data and satellite communications. See also ASCII, cryptography.

II

(as used in expressions)

American Standard Code for Information Interchange.

Beginner's All purpose Symbolic Instruction Code

bar code

binary code

building code

Clarendon Code

genetic code

German Civil Code

Hammurabi Code of

Justinian Code of

law code

machine code

Morse code

Napoleonic Code

Code Civil

slave code

Universal Product Code

zip code

black codes

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▪ communications

      in communications, an unvarying rule for replacing a piece of information such as a letter, word, or phrase with an arbitrarily selected equivalent. The term has been frequently misapplied and used as a synonym for cipher. In the past this blurring of the distinction between code and cipher was rather inconsequential; in fact, many historical ciphers would be more properly classified as codes according to present-day criteria.

      In modern communications systems, information is often both encoded and encrypted (or enciphered), and so an understanding of the difference between the two is important. Both codes and certain kinds of ciphers—substitution ciphers—replace elements of a message with other symbols; however, unlike codes, ciphers do so in accordance with a rule defined by a secret key known only to the transmitter of the information and the intended receiver. Without this secret key, a third party cannot invert the replacement to unscramble the cipher.

      During the early years of the 20th century, elaborate commercial codes were developed. One such system was the Baudot code, which encoded complete phrases into single words (five-letter groups) for use by telegraphers. This type of code proved inadequate for radio, however, and other, more advanced forms of communications subsequently developed. In recent years various codes have been introduced to accommodate computer data and satellite communications. See also cryptology; cipher.

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