BusyBox’s “Almquist shell” is not as rich as the Bash

• https://en.wikipedia.org/wiki/Almquist_shell
• https://linux.die.net/man/1/ash – the markup is in a terrible state
• https://en.wikipedia.org/wiki/Bash_(Unix_shell)

The problems with “ash” always most evident, if a shell script got written to work with Bash and needs adapting / downgrading to the “ash”.