Finding the Parent
==================
`^'
If you'd like to read the parent of the current article, and it is
not displayed in the summary buffer, you might still be able to.
That is, if the current group is fetched by NNTP, the parent
hasn't expired and the `References' in the current article are not
mangled, you can just press `^' or `A r'
(`gnus-summary-refer-parent-article'). If everything goes well,
you'll get the parent. If the parent is already displayed in the
summary buffer, point will just move to this article.
If given a positive numerical prefix, fetch that many articles
back into the ancestry. If given a negative numerical prefix,
fetch just that ancestor. So if you say `3 ^', Gnus will fetch
the parent, the grandparent and the grandgrandparent of the
current article. If you say `-3 ^', Gnus will only fetch the
grandgrandparent of the current article.
`A R (Summary)'
Fetch all articles mentioned in the `References' header of the
article (`gnus-summary-refer-references').
`A T (Summary)'
Display the full thread where the current article appears
(`gnus-summary-refer-thread'). This command has to fetch all the
headers in the current group to work, so it usually takes a while.
If you do it often, you may consider setting
`gnus-fetch-old-headers' to `invisible' (Note:Filling In
Threads). This won't have any visible effects normally, but
it'll make this command work a whole lot faster. Of course, it'll
make group entry somewhat slow.
The `gnus-refer-thread-limit' variable says how many old (i. e.,
articles before the first displayed in the current group) headers
to fetch when doing this command. The default is 200. If `t', all
the available headers will be fetched. This variable can be
overridden by giving the `A T' command a numerical prefix.
`M-^ (Summary)'
You can also ask the NNTP server for an arbitrary article, no
matter what group it belongs to. `M-^'
(`gnus-summary-refer-article') will ask you for a `Message-ID',
which is one of those long, hard-to-read thingies that look
something like `<38o6up$6f2@hymir.ifi.uio.no>'. You have to get
it all exactly right. No fuzzy searches, I'm afraid.
The current select method will be used when fetching by `Message-ID'
from non-news select method, but you can override this by giving this
command a prefix.
If the group you are reading is located on a back end that does not
support fetching by `Message-ID' very well (like `nnspool'), you can
set `gnus-refer-article-method' to an NNTP method. It would, perhaps,
be best if the NNTP server you consult is the one updating the spool
you are reading from, but that's not really necessary.
It can also be a list of select methods, as well as the special
symbol `current', which means to use the current select method. If it
is a list, Gnus will try all the methods in the list until it finds a
match.
Here's an example setting that will first try the current method, and
then ask Deja if that fails:
(setq gnus-refer-article-method
'(current
(nnweb "refer" (nnweb-type dejanews))))
Most of the mail back ends support fetching by `Message-ID', but do
not do a particularly excellent job at it. That is, `nnmbox' and
`nnbabyl' are able to locate articles from any groups, while `nnml' and
`nnfolder' are only able to locate articles that have been posted to
the current group. (Anything else would be too time consuming.)
`nnmh' does not support this at all.