Commercial code (communications)

Lore & Background

The first telegraphic codes appeared shortly after the telegraph itself, with the first codebook in use by 1845. By 1854, one eighth of telegrams sent between New York and New Orleans were written in code. Cable tolls were charged per word, and carefully constructed codes could reduce message lengths enormously. Early codes were compilations of tens of thousands of phrases with corresponding codewords, chosen to be pronounceable to minimize telegrapher errors; non-pronounceable words cost significantly more.

Regulations of the International Telegraph Union evolved over time. In 1879, coded telegrams were required to use only words from German, English, Spanish, French, Italian, Dutch, Portuguese, or Latin, though commercial codes already frequently used nonsense words. By 1903, regulations allowed any pronounceable word up to ten letters long. Codes were also designed to avoid confusion by using words that could not be easily mistaken by operators, as telegrapher errors could cause serious monetary damages—one such case reached the U.S. Supreme Court in Primrose v. Western Union Telephone Company.

The International Telegraph Convention distinguished between "code telegrams" (words with no intelligible meaning) and "cipher telegrams" (groups of figures or letters with secret meaning), with cipher telegrams subject to higher tolls. Many commercial codes therefore included both numbers and code words so users could choose.

Reader's Guide

Commercial codes were a practical response to the high cost of telegraphy, serving as a form of data compression long before the term existed. By encoding entire phrases into single five-letter words, businesses could drastically reduce the number of words in a telegram and thus the toll charged. These codes were not intended for secrecy—they were widely published—but for economy. The codes covered fields as varied as aviation, car dealerships, insurance, and cinema, containing phrases commonly used in those professions.

The use of commercial codes declined after the arrival of transatlantic telephone calls and next-day airmail, which rendered them obsolete by the mid-20th century. Their legacy lies in demonstrating an early, systematic approach to compressing information for economic efficiency, and in the colorful codewords that survive in historical records—such as BYOXO ("Are you trying to weasel out of our deal?") and BMULD ("You're a skunk!"). The codes also highlight the interplay between technology, regulation, and business practice in the era of global telegraphy.

Did You Know?

• The first telegraphic codebook was in use by 1845.
• Codewords were chosen to be pronounceable to minimize errors by telegraphers; non-pronounceable words cost more.
• The U.S. Supreme Court case Primrose v. Western Union Telephone Company arose from a telegrapher error that allegedly cost a wool dealer $20,000.