Your Mercurial example actually undermines your argument completely. I don't know "hg" at all, but when seeing "--no-backup" I immediately understand what that

Your Mercurial example actually undermines your argument completely. I don't know "hg" at all, but when seeing "--no-backup" I immediately understand what that flag does, something which would not be true if the command were "hg revert -C". Are you a casual user of command line tools? If you aren't, you know that command line options of anything become muscle memory if you use it long enough; at that point anything that stands between you and the correct result is nothing but a hindrance. The workflow on the command line is: 1. manual page; 2. SYNOPSIS section in the manual page; 3. EXAMPLES section in the manual; 4. run the application. If your operating system of choice has inadequate manual pages because developers say "I built in --long-options because I didn't want to figure out how to write a proper manual page", it's time to seriously contemplate ditching such a system, and replacing it with a real UNIX. At that point, when that happens, you lost and you lost big. As for zsh completion: A program simply needs to follow a specific protocol (take input, reply with the right output), and then be registered with the "complete" command. zsh comes with autocompletion for lots of things. So basically there is a hardcoded file with all the programs which the developers or the packagers of zsh were aware of, so that --long-options would work? So now you're assuming that everyone is using the application on the same substrate as you? What if that file isn't there on my OS? And how does that hardcoded hack scale? Yes, I can remember short command line options of tools I use often enough, and if I don't -- my operating system substrate comes with comprehensive manual pages, so I don't have to. I am empathically not a casual command line user that I would need --long-options because that's more intuitive, so --long-options suck because ergonomy trumps casual use. I will never provide GNU style of long options in my software, because I deeply care about my users, and I'll go out of my way to spare them from typing in the long term. What I will do is write a comprehensive manual page that will be a faithful companion and a good friend to them on their journey. And if they just don't care and want to hack something up on the quick -- I'm not that kind of a person, and it's not the kind of a relationship I want to have with my users; they can go somewhere else if they just needed to run some application casually. My tools are designed for long term, efficient use and comfort. Let people type --no-backup all day long "because it's more intuitive". Good luck with that.