From MozillaZine Knowledge Base
In Firefox’s fullscreen mode, toolbars and the tab strip may be hidden at the top of the screen and only shown on mouseover. This preference determines whether they should autohide.
Possible values and their effects
Automatically collapse toolbars and the tab strip in fullscreen mode and only show on mouseover. (Default)
Always show the toolbars and tab strip in fullscreen mode.
First checked in
2008-03-08 by Reed Loden (patch by Michael Ventnor)
Has an effect in