Systemd 257 released

https://lwn.net/Articles/1001657/

includes this ....

run0 gained a new switch --shell-prompt-prefix= that permits passing
in a string to display on each shell prompt as prefix. If not
specified otherwise this will show a superhero emoji (# ), in order
to visually communicate the temporarily elevated privileges a run0
session provides. This makes use of the $SHELL_PROMPT_PREFIX
environment variables mentioned below.


I pass no comment.