Picture should show "a typical MS Windows Domain Security network environment" but it seems to be missing on at least few mirrors. http://de.samba.org/samba/docs/man/projdoc/imagefiles/domain.png gives "404 - not found" error.
Works here, perhaps the mirror is out of sync?
This bug is really old. http://de.samba.org/samba/docs/man/Samba-HOWTO-Collection/samba-pdc.html now shows the right picture. I would consider this a FIXED.
Fixed now.
sorry for the same, cleaning up the database to prevent unecessary reopens of bugs.