I thought I understood this option for the run command, which was to allocate a TTY so that the user can attach to it and have STDOUT redirected to the active terminal. But then, I noticed that this is a valid parameter for the create command, and that there is no such parameter for the start command.
So, my question is, if you have created a docker container WITHOUT the --tty parameter, and you then start the container with --attach, does that mean there is no pseudo terminal to attach to?