The History of Signal Codes & Flags

The International Code of Signals is a form of communication for maritime vessels.

The British Board of Trade developed the International Code of Standards in 1857. These standards, which utilized codes and flag signals as a form of maritime communication, eventually became a universal standard for nautical vessels.

Adoption

This code was published in two parts, which contained universal and international signals plus signals exclusive to Britain. The first set of established codes used 70,000 signals and 18 flags.

Revisions

A British Board of Trade committee made revisions to the International Codes of Signals in 1887. Changes were made to the code and by 1897 all nautical-based nations received a copy of this newly formed code system.

Updated Standards

The International Code of Signals that was distributed in 1897 didn't prove to be effective during World War I. Spelling words with the coding system was ineffective when communicating information.

New Edition

Changes were made by 1930 and this edition was translated into several languages. This edition had two parts, which included the flags for visual signaling and radiotelegraphy. Aircraft and medical standards were added to the code and a standing committee was set in place to review and interpret the system.

Final Revision

Final updates for the code occurred in 1969 and included a universal alphanumeric code system. Flags are now used in various combinations and colors to convey a universally understandable message.

References

• CRW Flags: International Code of Signals
• Archives and Collections Society: Brief History of the International Code of Signals