The purpose of the International Code of Signals is to provide ways and means of communication in situations related essentially to safety of navigation and persons, especially when language difficulties arise. In the preparation of the Code, account was taken of the fact that wide application of radiotelephony and radiotelegraphy can provide simple and effective means of communication in plain language whenever language difficulties do not exist.
- The signals used consist of:
- Single-letter signals allocated to significations which are very urgent, important, or of very common use;
- Two-letter signals for General Signal Code, Chapter 2.
- Three-letter signals beginning with “M” for Medical Signal Code, Chapter 3,
- The Code follows the basic principle that each signal should have a complete meaning. This principle is followed throughout the Code; in certain cases complements are used, where necessary to supplement the available groups.