The kind of window system the terminal uses---either @code{graphic}
(any graphics-capable display), @code{x}, @code{pc} (for the MS-DOS
console), @code{w32} (for MS Windows 9X/NT/2K/XP), @code{haiku} (for
-Haiku), or @code{tty} (a non-graphics-capable display).
-@xref{Window Systems, window-system}.
+Haiku), @code{pgtk} (for GTK), or @code{tty} (a non-graphics-capable
+display). @xref{Window Systems, window-system}.
@item class
What kinds of colors the terminal supports---either @code{color},
@item
The kind of display associated with the terminal. This is the symbol
returned by the function @code{terminal-live-p} (i.e., @code{x},
-@code{t}, @code{w32}, @code{ns}, @code{pc}, or @code{haiku}).
+@code{t}, @code{w32}, @code{ns}, @code{pc}, @code{haiku}, or @code{pgtk}).
@xref{Frames}.
@item