Firefox address bar modifiers - the wiki:

The address bar has become our entry point to the internet these days. Firefox in its default configuration does some sort of smart guess on what you type there. If it resembles a URL then the browser makes that request. If not, it sends the string you typed to your default search engine. It also includes some fuzzy search matches from your history and all that, which is fine 90% of the time, but sometimes you need a bit more control over what results it shows you.

Screenshot of Firefox address bar modifiers

I had no idea. These are super-useful.

(via Hacker News)