Whenever you do something that changes the Gnus data (reading articles, catching up, killing/subscribing groups), the change is added to a special dribble buffer. This buffer is auto-saved the normal Emacs way. If your Emacs should crash before you have saved the .newsrc files, all changes you have made can be recovered from this file.
If Gnus detects this file at startup, it will ask the user whether to read it. The auto save file is deleted whenever the real startup file is saved.
nil, Gnus won't create and
maintain a dribble buffer. The default is
Gnus will put the dribble file(s) in
this variable is
nil, which it is by default, Gnus will dribble
into the directory where the .newsrc file is located. (This is
normally the user's home directory.) The dribble file will get the same
file permissions as the .newsrc file.
gnus-always-read-dribble-file is non-
nil, Gnus will
read the dribble file on startup without querying the user.