Prosigns for Morse code

Procedural signs or prosigns are shorthand signals used in Morse code telegraphy, for the purpose of simplifying and standardizing procedural protocols for land-line and radio communication. The procedural signs are distinct from conventional Morse code abbreviations, which consist mainly of brevity codes that convey messages to other parties with greater speed and accuracy. However, some codes are used both as prosigns and as single letters or punctuation marks, and for those, the distinction between a prosign and abbreviation is ambiguous, even in context.