Commercial code (communications)

In telecommunication, a commercial code is a code once used to save on cablegram costs ^[1][2]. Telegraph (and telex) companies have always charged based on the length of the message sent—and this has not changed since the 19th Century. To this day telex messages are charged by the word.

When telegraph messages were the state of the art in rapid long distance communication, elaborate commercial codes which encoded complete phrases into single words (commonly five-letter groups) were developed. For example "words" as BYOXO ("Are you trying to weasel out of our deal?"), LIOUY ("Why do you not answer my question?"), BMULD ("You're a skunk!"), or AYYLU ("Not clearly coded, repeat more clearly."). A "dictionary" of such "words" is a codebook. For telegraph offices that would not accept messages with non-words such as AYYLU, codebooks were compiled with only real words as codewords, sometimes using words from multiple accepted languages to expand the supply even though all the plaintext phrases were in one language.

Such commercial codes became obsolete in the late 20th century. They were replaced by much simpler (although admittedly more long-winded) codes such as Morse Code Abbreviations and Ten-code and Q code, and also by more compact automatic data compression algorithms.

In this context, "commercial code" (used purely to save cable costs, where the people communicating didn't care if anyone else could read their messages) is distinguished from similar "secret codes" used in cryptography.

Purpose

Initially the necessity for Commercial Codes was to save money. There was a boom in commercial telegraphy in the US (and Europe) from the 1880s into the 1920s, but messages were initially not cheap to send. This industrial sector was really where some of the first academic experimentations in lossless data compression and error correction (using checksums and check digits) took place.^{[citation needed]}

Elaborate commercial codes were developed that encoded common phrases as words or numbers. There were even a few commercial rating agencies (possibly linked to the book trade) that rated codebooks for their efficiency but these had more or less ceased operation by the mid-1930s.

Another aim of the telegraph codes was to reduce the risk of misunderstanding by avoiding having similar words mean similar things. There was also the goal of secrecy (or at least telecommunications communications privacy), as telegraph operators could potentially use information garnered from commercial and some kinds personal messages for their own personal profit.

Examples of these codes include the A.B.C Telegraphic Code, Bentleys Second Phrase Code, Slater's Telegraphy Code (1916), Western Union Universal Codebook (1907) and Unicode (1889).

In addition to more general commercial codes, there were a number of codes targeted at particular industries e.g. railways, timber, shipping, cotton and diplomats (the Western Union Universal Codebook was used by some US Embassies on a limited basis between 1905 and the mid 1930s).

Mechanics

In codes such as the A.B.C. Telegraphic code, code words could contain what would be recognized today in programming terms as parameters e.g. in the 'Freight and tonnage requirements' section, antitacte means Mozambique, loading at not more than two places, to ____, steamer for about ____ tons general cargo at ____ per ton on the d/w capacity to cargo.

The telegrapher would then fill in the 3 parameters, the destination, the number of tons and the price per ton.

The regulations of the International Telegraph Convention distinguished between 'code telegrams' which it describes as 'those composed of words the context of which has no intelligible meaning' and 'cipher telegrams' which it describes as 'those containing series of groups of figures or letters having a secret meaning or words not to be found in a standard dictionary of the language'.

Codes such as the A.B.C. Telegraphic Code, therefore, included both numbers and code words so the user could choose between the two.

Examples

Example code words:

• From the A.B.C Telegraphic Code (5th Edition)
  • paromella — in leaving the dock (harbour) struck the pier, damaging the stern
  • arimaspen — Phaeton with 6 B.H.P. two cylinder motor to seat four passengers speed — miles per hour
  • haubarer — Charterers will allow the option of carrying horses for ship's benefit

• From Bentley's Complete Phrase Code
  • oyfin — has not been reinsured
  • azkhe — clean bill of health
  • atgam — have they authorised?

• From the telegraphic cipher code specially adapted to the cotton trade
  • dress — the supply from India will be less than expected
  • insane — at what price, free on board and freight, can you offer us cotton for shipment by steamer sailing this week?
  • puncher — we anticipate rate of interest will be reduced by Bank of England

• From 'Unicode'^[3] (which, unlike the others, was intended for domestic use in addition to commercial; unrelated to the Unicode computing standard)
  • dionysia — Amputation is considered necessary
  • annosus — Confined yesterday, Twins, both dead, Mother not expected to live
  • cognosco — Dining out this evening, send my dress clothes here

In computer networking, commercial code could be thought of as the application layer, Morse code as the data link layer and the binary line code as the physical layer. However, fundamental differences between telegraphy and networking mean that some layers of the OSI model have no distinct analogs (namely the presentation, session, transport, and network layers). The responsibilities of these layers—which include error correction, addressing, delivery, and connection management—were jointly handled by telegraph operator protocol.

See also

• Great Western Railway telegraphic codes
• Telegraph code
• Telegraphese

References

1. ^ Bentley's and other standard codebooks
2. ^ Codebook collection
3. ^ "Unicode".: The Universal Telegraphic Phrase-book. (sixth ed.), Cassell & company limited, 1889, OCLC 67882848, http://openlibrary.org/books/OL23481712M/Unicode_._The_Universal_Telegraphic_Phrase-book._A_Code_of_Cypher_Words_for_Commercial_...