Documentation 
Section: The output of --help-terminal
gnome-terminal --help-terminal lists an option, "--tab," which should open a new tab in the last opened window according to the documentation. This does not seem to work, as "gnome-terminal --tab" seems to just open a new window.

Correct version:
It should either not list the option, or the feature should be implemented. 

Other information:
It'd be preferable, of course, to make the option work, but the shorter route would be to fix the documentation as to not be misleading.