I was looking for the electrical "standby" symbol - AKA IEC5009 / IEEE1621. You know, the circle with the line through it. The one that's on every single bloody piece of electronic equipment produced since the mid-1970s.
It's not in the Unicode standard.
I can, if I want, have a snowman ☃ or a reversed rotated floral bullet ☙.
What other useful and/or important symbols are missing from Unicode?
http://www.unicode.org/pending/proposals.html
I would be willing help work on this. We could keep the proposal documents on GitHub as a starting point for others who might need it in future.
If we are going to do this, let's include all the IEC power symbols and keep them together in a group:
IEC 5007, power on (line) symbol
IEC 5008, power off (circle) symbol
IEC 5009, standby (line through a broken circle) symbol
IEC 5010, power on/off (line inside a circle)
None of these currently in the Unicode pipeline http://www.unicode.org/alloc/Pipeline.html of symbols already proposed.