"pound sign"
Ehhh... in traditional unix-land it's called a Crunch.
Still have a sharp and amusing memory of the admin snapping at me at my first ever shell script on my first day of ever seeing unix, "NOT bang twiddle crunch : crunch bang twiddle! [for GOD's sake!...]"
.
(#!~ , which unix hands will recognise as (ugly but useful sh hackery) beginning of first line (last char only under unusual circs))