The "class hint" is a property of
GtkWindow window managers can read to decide how to
treat the window. Most window managers allow you to set
icons and other properties based on the class hint. Two
elements make up the hint. The
wmclass_name field should be unique for each kind
of toplevel window in an application (such as the main
window or a tools dialog). The
wmclass_class field is conventionally set to the
name of the application, capitalized. For example: xterm windows set these
properties to xterm
(name) and XTerm (class).
The GIMP toolbox sets its name to toolbox and its class to Gimp. The
gtk_window_set_wmclass() function sets these hints
for GtkWindow.
