I strongly suspect that --help is on the contrary less universal, given that there exist entire toolsets lacking the --help convention but having manual pages.

I strongly suspect that --help is on the contrary less universal, given that there exist entire toolsets lacking the --help convention but having manual pages. There was almost a quarter of a century's worth of Unix tools that developed before --help was invented. * https://unix.stackexchange.com/a/416796/5132 https://unix.stackexchange.com/a/416796/5132 * https://unix.stackexchange.com/questions/207136/ https://unix.stackexchange.com/questions/207136/