For each module, the table of contents shows an icon indicating subjectively how complete that module is:
The module doesn't exist yet, or near enough.
Content and organization has yet to be fully decided.
The information is scattered, incomplete, or may be unreliable.
Much of the information is there, but it needs to be touched up or organised. This is still usable.
The information is essentially complete. However, additions and improvements can still be made.