Is there a description of the gnus databse (files on disk)?

Is there a description of the gnus databse (files on disk)?

[Chris F Clark]

I would like to hack its contents to resolve a couple of problems. 

1) I (foolishly perhaps!) read a large and active newgroup
   (microsoft.public.windowsxp.general) and that causes a lot of cruft
   to be dumped in my News directory (in the cache and some other
   sub-directory). since the system I'm reading it on has a quota,
   plus I pay for storage.  I would like to safely prune that
   directory down to minimal size, without losing the few articles I
   have saved that may help me get my broken copy of xp working.

2) In other groups I read, I have articles marked * and !*.  The ones
   marked !* work correctly, they don't show up as unread, but they do
   persist.  The ones marked * show up as unread when I restart gnus.
   Now the ones marked just * probably got in that state when I last
   "cleaned up" my news directory (see 1).  So, I'l like to fiddle
   with the files to fix up those articles so that they show up as !*
   also.

To do all of this, it would help if I understood what the various
files in the news directory, the contents of the .newsrc, and whatever
other information gnus keeps from run to run.

So, if there is a pointer to something that documents the above that I
just don't know about, being made aware of it would be much
appreciated.

Thanks,
-Chris