2668: International Telecommunication Union (ITU) Standard Apr 7, 2022

Morse code was changed a number of times, finally cemented in 1865 with the International Telecommunication Union standard. This was mostly based on Morse's original system, as well as Gerke's modified European version, but some letters were redesigned wholesale like those for <O> (once • • with a medial pause, to later – – –) and <P> (once • • • • •, later • – – •). It also distinguished <I> and <J> that Gerke's system had as the same (• • without the medial pause), though it does not use Morse's original <J> (– • – •) because this was instead used for <C>.

This left only 4 characters unchanged since the original system. Per letter this did actually make things longer to spell & therefore become on the surface less efficient, but it led to a greater ease of understanding that would cancel that out. It has little resemblance to the original Morse code, but many still call it as such, even though the technical name would be the International Telecommunication Union (ITU) standard.

2667: International Morse Code Apr 6, 2022

There were lots of innovations that helped to spread Morse code, such as moving from paper to sound which speeds up comprehension and the switch from cables to radio waves, which originally could not transmit voices. Beyond that however, the real driver for the system's success was its early, wide adoption, such as at the 1851 Vienna conference which made it standard for many Central European countries, and even earlier when it was adopted among American railroads—eventually adopted broadly in America—in the two decades preceding the Civil War. That said, International Morse code (made by Friedrich Gerke) is different to American Morse code, and was influenced by the system already in place with the Hamburg railways. This standardized the length of dashes, which were somewhat variable in American Morse code, as well as adding in special characters not used for English.