allows you to set up Tabbed Browsing
Select this to display the Tabbed Browsing bar only when more then one Navigator tab is open.
Select this to prevent Mozilla from switching to a new tab when using "Open in a New Tab" to open a link.
Select this to open web page links in a new tab when clicking a link with the middle mouse button or while pressing Ctrl.
Select this to open a web-page link in a new tab when you type a URL in the Location Bar and press Ctrl+Enter.