You will get an error if you try to set them using setq . The valid instantiators for these specifiers are toolbar descriptors, as described above. See section Specifiers for more information. Most of the time, you will set default-toolbar , which allows the user to choose where the toolbar should go. This function sets the position that the default-toolbar will be displayed at.
Valid positions are the symbols top , bottom , left and right .
This function returns the position that the default-toolbar will be displayed at. You can also explicitly set a toolbar at a particular position. This function returns non-nil if object is a toolbar specifier. The variables to control the toolbar thickness, visibility status, and captioned status are all specifiers. See section Specifiers .