nil, show and update the summary buffer as it's being built. If
t, update the buffer after every line is inserted. If the value is an integer, n, update the display every n lines. The default is
nil, display an arrow in the fringe to indicate the current article.
Message-ID, it has to do something drastic. No articles are allowed to have the same
Message-ID, but this may happen when reading mail from some sources. Gnus allows you to customize what happens with this variable. If it is
nil(which is the default), Gnus will rename the
Message-ID(for display purposes only) and display the article as any other article. If this variable is
t, it won't display the article—it'll be as if it never existed.
For instance, the following function adds the list of cached articles to the list in one particular group:
(defun my-add-cached-articles (group articles) (if (string= group "some.group") (append gnus-newsgroup-cached articles) articles))
nil), that should be made global while the summary buffer is active.
Note: The default expressions will be evaluated (using function
eval) before assignment to the local variable rather than just
assigned to it. If the default expression is the symbol
that symbol will not be evaluated but the global value of the local
variable will be used instead.
These variables can be used to set variables in the group parameters while still allowing them to affect operations done in other buffers. For example:
(setq gnus-newsgroup-variables '(message-use-followup-to (gnus-visible-headers . "^From:\\|^Newsgroups:\\|^Subject:\\|^Date:\\|^To:")))
Also see Group Parameters.