Morse code prosigns or
procedural signals are special dot/dash sequence symbols e.g. (
· — · —) that for the most part do not represent written or printed alpha-numeric or punctuation text characters. Morse code prosigns are special (normally unwritten) symbols, that have particular functions, such as: indicating changes of transmission
communications protocol status, and indicating (or initiating) textual
white space formatting. These special Morse symbols, although preceding modern
teleprinter (teletypewriter) and computer
character set control characters by many decades, play a role similar to the (normally unprinted)
control characters of modern computer and
teleprinter character set codes such as the:
Baudot,
Murray,
ITA2,
ASCII,
Unicode and
EBCDIC codes.
Morse code prosign symbols have been used by
telegraphers (
AmE) /
telegraphists (
BrE) for over 140 years, predating modern
character set code
control characters by many decades. Traditionally Morse code is encoded or sent manually by telegraphists using hand operated
telegraph keys and decoded or copied as the Morse signals are received by ear in real time. Morse prosigns mostly constitute unique dot/dash sequence code symbols separate from those of alpha-numeric and punctuation Morse character symbols and have the same status as the normally written symbols. Mastery of prosigns and their usage is an important part of becoming a fluent
telegrapher /
telegraphist.