When on, the icon text of the window will be set to the value of 'iconstring' (if it is not empty), or to the name of the file currently being edited. Only the last part of the name is used. Overridden by the 'iconstring' option. Only works if the terminal supports setting window icons (currently only X11 GUI and terminals with a non-empty 't_IS' option - these are Unix xterm and iris-ansi by default, where 't_IS' is taken from the builtin termcap). When Vim was compiled with HAVE_X11 defined, the original icon will be restored if possible X11. See X11-icon for changing the icon on X11. For MS-Windows the icon can be changed, see windows-icon.

(default off, on when title can be restored)