Help! I mistakenly hit some unknown keyboard combination and ended up with an unidentified icon in the line numbers gutter-- what is it?? It is a black "0" on a dark green, raised square.

[img]http://www.flickr.com/photos/foryou/472772637/[/img]
Screenshot

That is a bookmark. Right click on the gutter / bookmark and choose toggle bookmarks to turn them on or off. They are actually very handy...

Ahh, thanks.. Without digging into the manual myself, do you know:
- what shortcut sets and unsets them (by default)
- what shortcut navigates them

There are actually quite a few shortcuts (too many to post), but you can find them by going toos / settings -- then click on editor shortcuts. Scroll down and you will see the Bookmarks area. Mine are set to Ctrl+K then the number I want (0-9) or Ctrl+Q then the number to go to the one you want.

I would actually prefer that you could just make any one you wanted at any time, and then have a list of all the ones you made in a tab (like eclipse does), but maybe that is a feature request for 5.0.x...

-r

Ctrl-Shift-0 to set 0th bookmark at current cursor position
Ctrl-0 to jump to it.