From MozillaZine Knowledge Base
The preference browser.urlbar.default.behavior makes it possible to customize the search behavior of the location bar in Firefox 3.5 and SeaMonkey 2. It replaces browser.urlbar.matchOnlyTyped, which is no longer supported.
The decimal value of this preference should be seen as a bitmap of 6 bits. If a bit in that bitmap is 1 then the corresponding filter will be applied. There are restrict filters (0:History, 1:Bookmarks, 2:Tags, 5:Typed) and match filters (3:Title, 4:URL).
The default of this preference in Firefox 3.5 and above is 0, meaning that no filtering is applied. 
The default of this preference in SeaMonkey 2 is 1, meaning that only History items are shown. 
Possible values and their effects
The section shows the meaning of the 6 bits (0-5) that are currently used to compose the default filter for the location bar.
Note: In SeaMonkey 2.0, only autocomplete entries for visited pages (History) are generated so setting the value to 2 (Restrict: Bookmarks) or 4 (Restrict: Tags) will not produce any results. In SeaMonkey 2.1 and later, all options are supported and produce the expected results, including the value 0.
Restrict: History (^)
Restrict: Bookmarks (*)
Restrict: Tags (+)
Match: Title (#)
Match: URL (@)
Restrict: Typed (~)
Restrict: Open Tabs (Switch to tab) (%)
Tools -> Options -> Privacy -> Location Bar
Other match and restrict bits that are set remain unaffected.
Edit -> Preferences -> Browser -> Location Bar
If both options are checked, the preference value becomes 49 (1+16+32).
First checked in
Has an effect in