From MozillaZine Knowledge Base

I partially reverted my last edit since I don't really understand how this preference works in Firefox 2. The preference now seems to be tied to whatever option is selected in "Tools -> Options -> Tabs -> New pages should be opened in: "a new tab" (3 -default?) or "a new window" (2) but that also toggles browser.link.open_newwindow. Hopefully someone else can fix it up. Alice 21:54, 8 March 2007 (UTC)

Without checking, my guess would be the developers simply assumed if someone wanted links opened in new tabs or new windows, they'd want it for both clicked links and external-to-the-app links. Documenting the UI as being tied to that option (with a note about the other pref being toggled) seems like the way to go. --Unarmed 04:45, 9 March 2007 (UTC)