I expect there will be people who reply to this comment to argue it should be "E-T-C" or "Et Cetera". You can ignore those people; they probably say "exclamation mark" instead of "bang".
For example, when I say "etsy" out loud, it makes it clear that I'm referring to the actual directory and not just saying "and other things".
It's a way to avoid a bad "who's on first" routine.
To take an example from further down in this thread: Likewise, in print, using cp and mv make it clear these specific things rather than the abstract concepts of copy and move.