| names in about:config | default key | returns |
|---|---|---|
| browser.urlbar.match.title | # | match text in the title |
| browser.urlbar.match.url | @ | match text in the URL |
| browser.urlbar.restrict.bookmark | * | only from bookmarks |
| browser.urlbar.restrict.history | ^ | only from browser history |
| browser.urlbar.restrict.tag | + | only tagged results |
| browser.urlbar.restrict.typed | ~ | only typed results (explicitly entered by address) |
| browser.urlbar.restrict.openpage | % | only open tabs; sans current |
Observe that the key can appear anywhere in your query (e.g., foo bar *, foo ~ bar).
For more info see http://kb.mozillazine.org/Location_Bar_Search