The license of the program, as a value of the %GtkLicense enumeration. The GtkAboutDialog will automatically fill out a standard disclaimer and link the user to the appropriate online resource for the license text. If %GTK_LICENSE_UNKNOWN is used, the link used will be the same specified in the GtkAboutDialog:website property. If %GTK_LICENSE_CUSTOM is used, the current contents of the GtkAboutDialog:license property are used. For any other GtkLicense value, the contents of the GtkAboutDialog:license property are also set by this property as a side effect.