About dialog often contain links and email addresses. #GtkAboutDialog
supports this by offering global hooks, which are called when the user
clicks on a link or email address, see gtk_about_dialog_set_email_hook()
-and gtk_about_dialog_set_url_hook().
+and gtk_about_dialog_set_url_hook(). Email addresses in the
+authors, documenters and artists properties are recognized by looking for
+<literal><user@host></literal>, URLs are recognized by looking for
+<literal>http://url</literal>, with <literal>url</literal> extending to
+the next space, tab or line break.
</para>
<para>
To make constructing a #GtkAboutDialog as convenient as possible, you can