What are the guidelines in creating widely used codes? What features do they have in common?



I’m curious to know how an invented code (e.g. Morse, Braille, the “10-4” code) comes into being, what considerations are there, and how does it get polished to “perfection” (nobody makes changes to it). Or maybe there are no guidelines, maybe a code is good if it satisfies some criteria, if so, what are these criteria?

In: Technology

Something stands out in your code list – the 10-4 code. This was never polished to a standard, and eventually died out *because* it was never properly standardized. Other codes, like morse or unicode or bluetooth or ascii, become standard because somebody important started using them. Morse code and telegraphic communication were born at the same time and worked together to serve a purpose. Morse was good enough, and all telegraph operators were trained to use it, so nobody ever replaced it and eventually it became a de-facto standard. In the case of something like braille, iirc, somebody important said “we should use this” and everybody agreed because nobody had any better ideas. This was the case for ascii, and later unicode. Whenever somebody invents a vastly better standard, everyone else tends to either adopt it or improve upon it even more. In general, the guidelines for modern encoding come down to basic computer science, and you might want to learn about binary and binary encryption if that interests you.

There’s actually a whole field of math known as [coding theory](https://en.wikipedia.org/wiki/Coding_theory) devoted to answering what makes a good code.

There are a lot of traits that you might want in an encoding. Which you want depends on the purpose of the code. Some examples:

* Short (you don’t want to use 1000 letters just to say “Hi”)
* Unambiguous (so “Attack at dawn” and “Hold position” don’t have the same encoding)
* Resistant to noise (so a flipped bit doesn’t change your meaning)
* Hard to decode without a key (so you can log into your bank account, but no one else can)

Morse code, for example, is designed to be as short as possible using only dots and dashes. The NATO phonetic alphabet is designed such that regardless of accent and staticky radio signal, the letters are still distinguishable.

Which codes become popular is mostly a matter of timing and historical accident.