The GtkAboutDialog supports secondary credits for artists, authors, the documentation team and translators, if any of these are set the GtkAboutDialog window will automatically display a "Credits" button , clicking this displays the secondary credits window.
set_authors() , set_artists() and set_documenters() all accept a string array of credits, if any of the credits are recognized as email addresses or urls then these are displayed as links assuming the appropriate hooks have been set with set_email_hook() or set_url_hook()
See also: get_authors()