Gtk.StatusIcon:tooltip-markup
"tooltip-markup" String : Read / Write
Sets the text of tooltip to be the given string, which is marked up with the <link linkend="PangoMarkupFormat">Pango text markup language</link>. Also see Gtk.set_markup.
This is a convenience property which will take care of getting the tooltip shown if the given string is not null. Gtk.StatusIcon:has-tooltip will automatically be set to true and the default handler for the Gtk.StatusIcon::query-tooltip signal will take care of displaying the tooltip.
On some platforms, embedded markup will be ignored.
Since 2.16