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[gnus] / texi / gnus.texi

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\gnusauthor{by Lars Magne Ingebrigtsen}
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Copyright \copyright{} 1995 Free Software Foundation, Inc. 

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.

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@ifinfo

This file documents Gnus, the GNU Emacs newsreader.

Copyright (C) 1995 Free Software Foundation, Inc.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

@ignore
Permission is granted to process this file through Tex and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph
(this paragraph not being relevant to the printed manual).

@end ignore
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided also that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.
@end ifinfo

@tex

@titlepage
@title September Gnus Manual

@author by Lars Magne Ingebrigtsen
@page

@vskip 0pt plus 1filll
Copyright @copyright{} 1995 Free Software Foundation, Inc. 

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.

@end titlepage
@page

@end tex


@node Top
@top The Gnus Newsreader

@ifinfo

You can read news (and mail) from within Emacs by using Gnus.  The news
can be gotten by any nefarious means you can think of---@sc{nntp}, local
spool or your mbox file.  All at the same time, if you want to push your
luck.

@end ifinfo

@iftex

@iflatex
\thispagestyle{empty}
@end iflatex

Gnus is the advanced, self-documenting, customizable, extensible
unreal-time newsreader for GNU Emacs.  

Oops.  That sounds oddly familiar, so let's start over again to avoid
being accused of plagiarism:

Gnus is a message-reading laboratory.  It will let you look at just
about anything as if it were a newsgroup.  You can read mail with it,
you can browse directories with it, you can @code{ftp} with it---you can
even read news with it!

Gnus tries to empower people who read news the same way Emacs empowers
people who edit text.  Gnus sets no limits to what the user should be
allowed to do.  Users are encouraged to extend Gnus to make it behave
like they want it to behave.  A program should not control people;
people should be empowered to do what they want by using (or abusing)
the program.

@end iftex


@menu
* Starting Up::           Finding news can be a pain.
* The Group Buffer::      Selecting, subscribing and killing groups.
* The Summary Buffer::    Reading, saving and posting articles.
* The Article Buffer::    Displaying and handling articles.
* Composing Messages::    Information on sending mail and news.
* Select Methods::        Gnus reads all messages from various select methods.
* Scoring::               Assigning values to articles.
* Various::               General purpose settings.
* The End::               Farewell and goodbye.
* Appendices::            Terminology, Emacs intro, FAQ, History, Internals.
* Index::                 Variable, function and concept index.
* Key Index::             Key Index.
@end menu


@node Starting Up
@chapter Starting Gnus
@cindex starting up

@kindex M-x gnus
@findex gnus
If your system administrator has set things up properly, starting Gnus
and reading news is extremely easy---you just type @kbd{M-x gnus} in
your Emacs. 

@findex gnus-other-frame
@kindex M-x gnus-other-frame
If you want to start Gnus in a different frame, you can use the command
@kbd{M-x gnus-other-frame} instead.

If things do not go smoothly at startup, you have to twiddle some
variables. 

@menu
* Finding the News::    Choosing a method for getting news.
* The First Time::      What does Gnus do the first time you start it?
* The Server is Down::  How can I read my mail then?
* Slave Gnusii::        You can have more than one Gnus active at a time.
* Fetching a Group::    Starting Gnus just to read a group.
* New Groups::          What is Gnus supposed to do with new groups?
* Startup Files::       Those pesky startup files---@file{.newsrc}.
* Auto Save::           Recovering from a crash.
* The Active File::     Reading the active file over a slow line Takes Time.
* Startup Variables::   Other variables you might change.
@end menu


@node Finding the News
@section Finding the News

@vindex gnus-select-method
@c @head
The @code{gnus-select-method} variable says where Gnus should look for
news.  This variable should be a list where the first element says
@dfn{how} and the second element says @dfn{where}.  This method is your
native method.  All groups that are not fetched with this method are
foreign groups.

For instance, if the @samp{news.somewhere.edu} @sc{nntp} server is where
you want to get your daily dosage of news from, you'd say:

@lisp
(setq gnus-select-method '(nntp "news.somewhere.edu"))
@end lisp

If you want to read directly from the local spool, say:

@lisp
(setq gnus-select-method '(nnspool ""))
@end lisp

If you can use a local spool, you probably should, as it will almost
certainly be much faster.

@vindex gnus-nntpserver-file
@cindex NNTPSERVER
@cindex @sc{nntp} server
If this variable is not set, Gnus will take a look at the
@code{NNTPSERVER} environment variable.  If that variable isn't set,
Gnus will see whether @code{gnus-nntpserver-file}
(@file{/etc/nntpserver} by default) has any opinions on the matter.  If
that fails as well, Gnus will will try to use the machine that is
running Emacs as an @sc{nntp} server.  That's a long-shot, though.

@vindex gnus-nntp-server
If @code{gnus-nntp-server} is set, this variable will override
@code{gnus-select-method}.  You should therefore set
@code{gnus-nntp-server} to @code{nil}, which is what it is by default.

@vindex gnus-secondary-servers
You can also make Gnus prompt you interactively for the name of an
@sc{nntp} server.  If you give a non-numerical prefix to @code{gnus}
(i.e., @kbd{C-u M-x gnus}), Gnus will let you choose between the servers
in the @code{gnus-secondary-servers} list (if any).  You can also just
type in the name of any server you feel like visiting.

@findex gnus-group-browse-foreign-server
@kindex B (Group)
However, if you use one @sc{nntp} server regularly and are just
interested in a couple of groups from a different server, you would be
better served by using the @kbd{B} command in the group buffer.  It will
let you have a look at what groups are available, and you can subscribe
to any of the groups you want to.  This also makes @file{.newsrc}
maintenance much tidier.  @xref{Foreign Groups}.

@vindex gnus-secondary-select-methods
@c @head
A slightly different approach to foreign groups is to set the
@code{gnus-secondary-select-methods} variable.  The select methods
listed in this variable are in many ways just as native as the
@code{gnus-select-method} server.  They will also be queried for active
files during startup (if that's required), and new newsgroups that
appear on these servers will be subscribed (or not) just as native
groups are.

For instance, if you use the @code{nnmbox} backend to read your mail, you
would typically set this variable to

@lisp
(setq gnus-secondary-select-methods '((nnmbox "")))
@end lisp


@node The First Time
@section The First Time
@cindex first time usage

If no startup files exist, Gnus will try to determine what groups should
be subscribed by default.

@vindex gnus-default-subscribed-newsgroups
If the variable @code{gnus-default-subscribed-newsgroups} is set, Gnus
will subscribe you to just those groups in that list, leaving the rest
killed.  Your system administrator should have set this variable to
something useful.

Since she hasn't, Gnus will just subscribe you to a few randomly picked
groups (i.e., @samp{*.newusers}).  (@dfn{Random} is here defined as
@dfn{whatever Lars thinks you should read}.)

You'll also be subscribed to the Gnus documentation group, which should
help you with most common problems.  

If @code{gnus-default-subscribed-newsgroups} is @code{t}, Gnus will just
use the normal functions for handling new groups, and not do anything
special.


@node The Server is Down
@section The Server is Down
@cindex server errors

If the default server is down, Gnus will understandably have some
problems starting.  However, if you have some mail groups in addition to
the news groups, you may want to start Gnus anyway.

Gnus, being the trusting sort of program, will ask whether to proceed
without a native select method if that server can't be contacted.  This
will happen whether the server doesn't actually exist (i.e., you have
given the wrong address) or the server has just momentarily taken ill
for some reason or other.  If you decide to continue and have no foreign
groups, you'll find it difficult to actually do anything in the group
buffer.  But, hey, that's your problem.  Blllrph!

@findex gnus-no-server
@c @head
If you know that the server is definitely down, or you just want to read
your mail without bothering with the server at all, you can use the
@code{gnus-no-server} command to start Gnus.  That might come in handy
if you're in a hurry as well.


@node Slave Gnusii
@section Slave Gnusiï
@cindex slave

You might want to run more than one Emacs with more than one Gnus at the
same time.  If you are using different @file{.newsrc} files (eg., if you
are using the two different Gnusiï to read from two different servers),
that is no problem whatsoever.  You just do it.

The problem appears when you want to run two Gnusiï that use the same
@code{.newsrc} file.

To work around that problem some, we here at the Think-Tank at the Gnus
Towers have come up with a new concept: @dfn{Masters} and
@dfn{servants}.  (We have applied for a patent on this concept, and have
taken out a copyright on those words.  If you wish to use those words in
conjunction with each other, you have to send $1 per usage instance to
me.  Usage of the patent (@dfn{Master/Slave Relationships In Computer
Applications}) will be much more expensive, of course.)

Anyways, you start one Gnus up the normal way with @kbd{M-x gnus} (or
however you do it).  Each subsequent slave Gnusiï should be started with
@kbd{M-x gnus-slave}.  These slaves won't save normal @file{.newsrc}
files, but instead save @dfn{slave files} that contains information only
on what groups have been read in the slave session.  When a master Gnus
starts, it will read (and delete) these slave files, incorporating all
information from them.  (The slave files will be read in the sequence
they were created, so the latest changes will have precedence.)

Information from the slave files has, of course, precedence over the
information in the normal (i. e., master) @code{.newsrc} file.


@node Fetching a Group
@section Fetching a Group

@findex gnus-fetch-group
It it sometime convenient to be able to just say ``I want to read this
group and I don't care whether Gnus has been started or not''.  This is
perhaps more useful for people who write code than for users, but the
command @code{gnus-fetch-group} provides this functionality in any case.
It takes the group name as a parameter.


@node New Groups
@section New Groups
@cindex new groups

@vindex gnus-subscribe-newsgroup-method
What Gnus does when it encounters a new group is determined by the
@code{gnus-subscribe-newsgroup-method} variable.

This variable should contain a function.  Some handy pre-fab values
are:

@table @code

@item gnus-subscribe-zombies
@vindex gnus-subscribe-zombies
Make all new groups zombies.  You can browse the zombies later (with
@kbd{A z}) and either kill them all off properly, or subscribe to them.
This is the default.

@item gnus-subscribe-randomly
@vindex gnus-subscribe-randomly
Subscribe all new groups randomly.

@item gnus-subscribe-alphabetically
@vindex gnus-subscribe-alphabetically
Subscribe all new groups alphabetically.

@item gnus-subscribe-hierarchically
@vindex gnus-subscribe-hierarchically
Subscribe all new groups hierarchically.

@item gnus-subscribe-interactively
@vindex gnus-subscribe-interactively
Subscribe new groups interactively.  This means that Gnus will ask
you about @strong{all} new groups.

@item gnus-subscribe-killed
@vindex gnus-subscribe-killed
Kill all new groups.

@end table

@vindex gnus-subscribe-hierarchical-interactive
A closely related variable is
@code{gnus-subscribe-hierarchical-interactive}.  (That's quite a
mouthful.)  If this variable is non-@code{nil}, Gnus will ask you in a
hierarchical fashion whether to subscribe to new groups or not.  Gnus
will ask you for each sub-hierarchy whether you want to descend the
hierarchy or not.  

One common mistake is to set the variable a few paragraphs above to
@code{gnus-subscribe-hierarchical-interactive}.  This is an error.  This
will not work.  This is ga-ga.  So don't do it.

A nice and portable way to control which new newsgroups should be
subscribed (or ignored) is to put an @dfn{options} line at the start of
the @file{.newsrc} file.  Here's an example:

@example
options -n !alt.all !rec.all sci.all
@end example

@vindex gnus-subscribe-options-newsgroup-method
This line obviously belongs to a serious-minded intellectual scientific
person (or she may just be plain old boring), because it says that all
groups that have names beginning with @samp{alt} and @samp{rec} should
be ignored, and all groups with names beginning with @samp{sci} should
be subscribed.  Gnus will not use the normal subscription method for
subscribing these groups.
@code{gnus-subscribe-options-newsgroup-method} is used instead.  This
variable defaults to @code{gnus-subscribe-alphabetically}.

@vindex gnus-options-not-subscribe
@vindex gnus-options-subscribe
If you don't want to mess with your @file{.newsrc} file, you can just
set the two variables @code{gnus-options-subscribe} and
@code{gnus-options-not-subscribe}.  These two variables do exactly the
same as the @file{.newsrc} @samp{options -n} trick.  Both are regexps,
and if the the new group matches the former, it will be unconditionally
subscribed, and if it matches the latter, it will be ignored.

@vindex gnus-auto-subscribed-groups
Yet another variable that meddles here is
@code{gnus-auto-subscribed-groups}.  It works exactly like
@code{gnus-options-subscribe}, and is therefore really superfluous, but I
thought it would be nice to have two of these.  This variable is more
meant for setting some ground rules, while the other variable is used
more for user fiddling.  By default this variable makes all new groups
that come from mail backends (@code{nnml}, @code{nnbabyl},
@code{nnfolder}, @code{nnmbox}, and @code{nnmh}) subscribed.  If you
don't like that, just set this variable to @code{nil}.

@vindex gnus-check-new-newsgroups
If you are satisfied that you really never want to see any new groups,
you could set @code{gnus-check-new-newsgroups} to @code{nil}.  This will
also save you some time at startup.  Even if this variable is
@code{nil}, you can always subscribe to the new groups just by pressing
@kbd{U} in the group buffer (@pxref{Group Maintenance}).  This variable
is @code{t} by default.

Gnus normally determines whether a group is new or not by comparing the
list of groups from the active file(s) with the lists of subscribed and
dead groups.  This isn't a particularly fast method.  If
@code{gnus-check-new-newsgroups} is @code{ask-server}, Gnus will ask the
server for new groups since the last time.  This is both faster &
cheaper.  This also means that you can get rid of the list of killed
groups altogether, so you may set @code{gnus-save-killed-list} to
@code{nil}, which will save time both at startup, at exit, and all over.
Saves disk space, too.  Why isn't this the default, then?
Unfortunately, not all servers support this command. 

I bet I know what you're thinking now: How do I find out whether my
server supports @code{ask-server}?  No?  Good, because I don't have a
fail-safe answer.  I would suggest just setting this variable to
@code{ask-server} and see whether any new groups appear within the next
few days.  If any do, then it works.  If any don't, then it doesn't
work.  I could write a function to make Gnus guess whether the server
supports @code{ask-server}, but it would just be a guess.  So I won't.
You could @code{telnet} to the server and say @code{HELP} and see
whether it lists @samp{NEWGROUPS} among the commands it understands.  If
it does, then it might work.  (But there are servers that lists
@samp{NEWGROUPS} without supporting the function properly.)

This variable can also be a list of select methods.  If so, Gnus will
issue an @code{ask-server} command to each of the select methods, and
subscribe them (or not) using the normal methods.  This might be handy
if you are monitoring a few servers for new groups.  A side effect is
that startup will take much longer, so you can meditate while waiting.
Use the mantra ``dingnusdingnusdingnus'' to achieve permanent bliss.


@node Startup Files
@section Startup Files
@cindex startup files
@cindex .newsrc

Now, you all know about the @file{.newsrc} file.  All subscription
information is traditionally stored in this file.

Things got a bit more complicated with @sc{gnus}.  In addition to
keeping the @file{.newsrc} file updated, it also used a file called
@file{.newsrc.el} for storing all the information that didn't fit into
the @file{.newsrc} file.  (Actually, it also duplicated everything in
the @file{.newsrc} file.)  @sc{gnus} would read whichever one of these
files was the most recently saved, which enabled people to swap between
@sc{gnus} and other newsreaders.

That was kinda silly, so Gnus went one better: In addition to the
@file{.newsrc} and @file{.newsrc.el} files, Gnus also has a file called
@file{.newsrc.eld}.  It will read whichever of these files that are most
recent, but it will never write a @file{.newsrc.el} file.

@vindex gnus-save-newsrc-file
You can turn off writing the @file{.newsrc} file by setting
@code{gnus-save-newsrc-file} to @code{nil}, which means you can delete
the file and save some space, as well as making exit from Gnus faster.
However, this will make it impossible to use other newsreaders than
Gnus.  But hey, who would want to, right?

@vindex gnus-save-killed-list
If @code{gnus-save-killed-list} (default @code{t}) is @code{nil}, Gnus
will not save the list of killed groups to the startup file.  This will
save both time (when starting and quitting) and space (on disk).  It
will also means that Gnus has no record of what groups are new or old,
so the automatic new groups subscription methods become meaningless.
You should always set @code{gnus-check-new-newsgroups} to @code{nil} or
@code{ask-server} if you set this variable to @code{nil} (@pxref{New
Groups}).

@vindex gnus-startup-file
The @code{gnus-startup-file} variable says where the startup files are.
The default value is @file{~/.newsrc}, with the Gnus (El Dingo) startup
file being whatever that one is with a @samp{.eld} appended.

@vindex gnus-save-newsrc-hook
@vindex gnus-save-quick-newsrc-hook
@vindex gnus-save-standard-newsrc-hook
@code{gnus-save-newsrc-hook} is called before saving any of the newsrc
files, while @code{gnus-save-quick-newsrc-hook} is called just before
saving the @file{.newsrc.eld} file, and
@code{gnus-save-standard-newsrc-hook} is called just before saving the
@file{.newsrc} file.  The latter two are commonly used to turn version
control on or off.  Version control is off by default when saving the
startup files.


@node Auto Save
@section Auto Save
@cindex dribble file
@cindex auto-save

Whenever you do something that changes the Gnus data (reading articles,
catching up, killing/subscribing groups), the change is added to a
special @dfn{dribble buffer}.  This buffer is auto-saved the normal
Emacs way.  If your Emacs should crash before you have saved the
@file{.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.

@vindex gnus-use-dribble-file
If @code{gnus-use-dribble-file} is @code{nil}, Gnus won't create and
maintain a dribble buffer.  The default is @code{t}.

@vindex gnus-dribble-directory
Gnus will put the dribble file(s) in @code{gnus-dribble-directory}.  If
this variable is @code{nil}, which it is by default, Gnus will dribble
into the directory where the @file{.newsrc} file is located.  (This is
normally the user's home directory.)  The dribble file will get the same
file permissions as the @code{.newsrc} file.


@node The Active File
@section The Active File
@cindex active file
@cindex ignored groups

When Gnus starts, or indeed whenever it tries to determine whether new
articles have arrived, it reads the active file.  This is a very large
file that lists all the active groups and articles on the server.

@vindex gnus-ignored-newsgroups
Before examining the active file, Gnus deletes all lines that match the
regexp @code{gnus-ignored-newsgroups}.  This is done primarily to reject
any groups with bogus names, but you can use this variable to make Gnus
ignore hierarchies you aren't ever interested in.  However, this is not
recommended.  In fact, it's highly discouraged.  Instead, @pxref{New
Groups} for an overview of other variables that can be used instead.

@c This variable is
@c @code{nil} by default, and will slow down active file handling somewhat
@c if you set it to anything else.

@vindex gnus-read-active-file
@c @head
The active file can be rather Huge, so if you have a slow network, you
can set @code{gnus-read-active-file} to @code{nil} to prevent Gnus from
reading the active file.  This variable is @code{t} by default.

Gnus will try to make do by getting information just on the groups that
you actually subscribe to.

Note that if you subscribe to lots and lots of groups, setting this
variable to @code{nil} will probably make Gnus slower, not faster.  At
present, having this variable @code{nil} will slow Gnus down
considerably, unless you read news over a 2400 baud modem.  

This variable can also have the value @code{some}.  Gnus will then
attempt to read active info only on the subscribed groups.  On some
servers this is quite fast (on sparkling, brand new INN servers that
support the @code{LIST ACTIVE group} command), on others this isn't fast
at all.  In any case, @code{some} should be faster than @code{nil}, and
is certainly faster than @code{t} over slow lines.

If this variable is @code{nil}, Gnus will ask for group info in total
lock-step, which isn't very fast.  If it is @code{some} and you use an
@sc{nntp} server, Gnus will pump out commands as fast as it can, and
read all the replies in one swoop.  This will normally result in better
performance, but if the server does not support the aforementioned
@code{LIST ACTIVE group} command, this isn't very nice to the server.

In any case, if you use @code{some} or @code{nil}, you should definitely
kill all groups that you aren't interested in to speed things up.


@node Startup Variables
@section Startup Variables

@table @code

@item gnus-load-hook
@vindex gnus-load-hook
A hook that is run while Gnus is being loaded.  Note that this hook will
normally be run just once in each Emacs session, no matter how many
times you start Gnus.

@item gnus-startup-hook
@vindex gnus-startup-hook
A hook that is run after starting up Gnus successfully.

@item gnus-check-bogus-newsgroups
@vindex gnus-check-bogus-newsgroups
If non-@code{nil}, Gnus will check for and delete all bogus groups at
startup.  A @dfn{bogus group} is a group that you have in your
@file{.newsrc} file, but doesn't exist on the news server.  Checking for
bogus groups can take quite a while, so to save time and resources it's
best to leave this option off, and do the checking for bogus groups once
in a while from the group buffer instead (@pxref{Group Maintenance}).

@item gnus-inhibit-startup-message
@vindex gnus-inhibit-startup-message
If non-@code{nil}, the startup message won't be displayed.  That way,
your boss might not notice that you are reading news instead of doing
your job as easily.

@item gnus-no-groups-message
@vindex gnus-no-groups-message
Message displayed by Gnus when no groups are available.
@end table


@node The Group Buffer
@chapter The Group Buffer
@cindex group buffer

The @dfn{group buffer} lists all (or parts) of the available groups.  It
is the first buffer shown when Gnus starts, and will never be killed as
long as Gnus is active.

@menu
* Group Buffer Format::    Information listed and how you can change it.
* Group Maneuvering::      Commands for moving in the group buffer.
* Selecting a Group::      Actually reading news.
* Subscription Commands::  Unsubscribing, killing, subscribing.
* Group Levels::           Levels? What are those, then?
* Group Score::            A mechanism for finding out what groups you like.
* Marking Groups::         You can mark groups for later processing.
* Foreign Groups::         Creating and editing groups.
* Group Parameters::       Each group may have different parameters set.
* Listing Groups::         Gnus can list various subsets of the groups.
* Sorting Groups::         Re-arrange the group order.
* Group Maintenance::      Maintaining a tidy @file{.newsrc} file.
* Browse Foreign Server::  You can browse a server.  See what it has to offer.
* Exiting Gnus::           Stop reading news and get some work done.
* Group Topics::           A folding group mode divided into topics.
* Misc Group Stuff::       Other stuff that you can to do.
@end menu


@node Group Buffer Format
@section Group Buffer Format
@cindex group buffer format

@menu 
* Group Line Specification::       Deciding how the group buffer is to look.
* Group Modeline Specification::   The group buffer modeline.
* Group Highlighting::             Having nice colors in the group buffer.
@end menu


@node Group Line Specification
@subsection Group Line Specification

The default format of the group buffer is nice and dull, but you can
make it as exciting and ugly as you feel like.

Here's a couple of example group lines:

@example
     25: news.announce.newusers
 *    0: alt.fan.andrea-dworkin
@end example

Quite simple, huh?

You can see that there are 25 unread articles in
@samp{news.announce.newusers}.  There are no unread articles, but some
ticked articles, in @samp{alt.fan.andrea-dworkin} (see that little
asterisk at the beginning of the line?)

@vindex gnus-group-line-format
You can change that format to whatever you want by fiddling with the
@code{gnus-group-line-format} variable.  This variable works along the
lines of a @code{format} specification, which is pretty much the same as
a @code{printf} specifications, for those of you who use (feh!) C.
@xref{Formatting Variables}. 

The default value that produced those lines above is 
@samp{%M%S%5y: %(%g%)\n}.

There should always be a colon on the line; the cursor always moves to
the colon after performing an operation.  Nothing else is required---not
even the group name.  All displayed text is just window dressing, and is
never examined by Gnus.  Gnus stores all real information it needs using
text properties.

(Note that if you make a really strange, wonderful, spreadsheet-like
layout, everybody will believe you are hard at work with the accounting
instead of wasting time reading news.)

Here's a list of all available format characters:

@table @samp

@item M    
Only marked articles.

@item S
Whether the group is subscribed.

@item L    
Level of subscribedness.

@item N
Number of unread articles.

@item I
Number of dormant articles.

@item T
Number of ticked articles.

@item R
Number of read articles.

@item t
Total number of articles.

@item y
Number of unread, unticked, non-dormant articles.

@item i
Number of ticked and dormant articles.

@item g
Full group name.

@item G
Group name.

@item D
Newsgroup description.

@item o
@samp{m} if moderated.

@item O
@samp{(m)} if moderated.

@item s
Select method.

@item n
Select from where.

@item z
A string that looks like @samp{<%s:%n>} if a foreign select method is
used.

@item P
Indentation based on the level of the topic (@pxref{Group Topics}). 

@item c
@vindex gnus-group-uncollapsed-levels
Short (collapsed) group name.  The @code{gnus-group-uncollapsed-levels}
variable says how many levels to leave at the end of the group name.
The default is @code{1}.

@item u
User defined specifier.  The next character in the format string should
be a letter.  @sc{gnus} will call the function
@code{gnus-user-format-function-}@samp{X}, where @samp{X} is the letter
following @samp{%u}.  The function will be passed the current headers as
argument.  The function should return a string, which will be inserted
into the buffer just like information from any other specifier.
@end table

@cindex *
All the ``number-of'' specs will be filled with an asterisk (@samp{*})
if no info is available---for instance, if it is a non-activated foreign
group, or a bogus (or semi-bogus) native group.


@node Group Modeline Specification
@subsection Group Modeline Specification

@vindex gnus-group-mode-line-format
The mode line can be changed by setting
(@code{gnus-group-mode-line-format}).  It doesn't understand that many
format specifiers:

@table @samp
@item S
The native news server.
@item M
The native select method.
@end table


@node Group Highlighting
@subsection Group Highlighting

@vindex gnus-group-highlight
Highlighting in the group buffer is controlled by the
@code{gnus-group-highlight} variable.  This is an alist with elements
that look like @var{(form . face)}.  If @var{form} evaluates to
something non-@code{nil}, the @var{face} will be used on the line.

Here's an example value for this variable that might look nice if the
background is dark:

@lisp
(setq gnus-group-highlight
    `(((> unread 200) . 
       ,(custom-face-lookup "Red" nil nil t nil nil))
      ((and (< level 3) (zerop unread)) . 
       ,(custom-face-lookup "SeaGreen" nil nil t nil nil))
      ((< level 3) . 
       ,(custom-face-lookup "SpringGreen" nil nil t nil nil))
      ((zerop unread) . 
       ,(custom-face-lookup "SteelBlue" nil nil t nil nil))
      (t . 
       ,(custom-face-lookup "SkyBlue" nil nil t nil nil))
      ))
@end lisp

Variables that are dynamically bound when the forms are evaluated
include:

@table @code
@item group
The group name.
@item unread
The number of unread articles in the group.
@item method
The select method.
@item mailp
Whether the group is a mail group.
@item level
The level of the group.
@item score
The score of the group.
@item ticked 
The number of ticked articles in the group.
@end table

When the forms are @code{eval}ed, point is at the beginning of the line
of the group in question, so you can use many of the normal Gnus
functions for snarfing info on the group.

@vindex gnus-group-update-hook
@findex gnus-group-highlight-line
@code{gnus-group-update-hook} is called when a group line is changed.
It will not be called when @code{gnus-visual} is @code{nil}.  This hook
calls @code{gnus-group-highlight-line} by default.


@node Group Maneuvering
@section Group Maneuvering
@cindex group movement

All movement commands understand the numeric prefix and will behave as
expected, hopefully. 

@table @kbd

@item n
@kindex n (Group)
@findex gnus-group-next-unread-group
Go to the next group that has unread articles
(@code{gnus-group-next-unread-group}).

@item p

@itemx DEL
@kindex DEL (Group)
@kindex p (Group)
@findex gnus-group-prev-unread-group
Go to the previous group group that has unread articles
(@code{gnus-group-prev-unread-group}).

@item N
@kindex N (Group)
@findex gnus-group-next-group
Go to the next group (@code{gnus-group-next-group}).

@item P
@kindex P (Group)
@findex gnus-group-prev-group
Go to the previous group (@code{gnus-group-prev-group}).

@item M-p
@kindex M-p (Group)
@findex gnus-group-next-unread-group-same-level
Go to the next unread group on the same level (or lower)
(@code{gnus-group-next-unread-group-same-level}). 

@item M-n
@kindex M-n (Group)
@findex gnus-group-prev-unread-group-same-level
Go to the previous unread group on the same level (or lower)
(@code{gnus-group-prev-unread-group-same-level}). 
@end table

Three commands for jumping to groups:

@table @kbd

@item j
@kindex j (Group)
@findex gnus-group-jump-to-group
Jump to a group (and make it visible if it isn't already)
(@code{gnus-group-jump-to-group}).  Killed groups can be jumped to, just
like living groups.

@item ,
@kindex , (Group)
@findex gnus-group-best-unread-group
Jump to the unread group with the lowest level
(@code{gnus-group-best-unread-group}). 

@item .
@kindex . (Group)
@findex gnus-group-first-unread-group
Jump to the first group with unread articles
(@code{gnus-group-first-unread-group}).  
@end table

@vindex gnus-group-goto-unread
If @code{gnus-group-goto-unread} is @code{nil}, all the movement
commands will move to the next group, not the next unread group.  Even
the commands that say they move to the next unread group.  The default
is @code{t}.


@node Selecting a Group
@section Selecting a Group
@cindex group selection

@table @kbd

@item SPACE
@kindex SPACE (Group)
@findex gnus-group-read-group
Select the current group, switch to the summary buffer and display the
first unread article (@code{gnus-group-read-group}).  If there are no
unread articles in the group, or if you give a non-numerical prefix to
this command, Gnus will offer to fetch all the old articles in this
group from the server.  If you give a numerical prefix @var{N}, Gnus
will fetch @var{N} number of articles.  If @var{N} is positive, fetch
the @var{N} newest articles, if @var{N} is negative, fetch the
@var{abs(N)} oldest articles.

@item RET
@kindex RET (Group)
@findex gnus-group-select-group
Select the current group and switch to the summary buffer
(@code{gnus-group-select-group}).  Takes the same arguments as
@code{gnus-group-read-group}---the only difference is that this command
does not display the first unread article automatically upon group
entry. 

@item M-RET
@kindex M-RET (Group)
@findex gnus-group-quick-select-group
This does the same as the command above, but tries to do it with the
minimum amount off fuzz (@code{gnus-group-quick-select-group}).  No
scoring/killing will be performed, there will be no highlights and no
expunging.  This might be useful if you're in a real hurry and have to
enter some humongous group.

@item M-SPACE
@kindex M-RET (Group)
@findex gnus-group-visible-select-group
This is yet one more command that does the same as the one above, but
this one does it without expunging and hiding dormants
(@code{gnus-group-visible-select-group}).  

@item c
@kindex c (Group)
@findex gnus-group-catchup-current
@vindex gnus-group-catchup-group-hook
Mark all unticked articles in this group as read
(@code{gnus-group-catchup-current}).
@code{gnus-group-catchup-group-hook} is when catching up a group from
the group buffer.

@item C
@kindex C (Group)
@findex gnus-group-catchup-current-all
Mark all articles in this group, even the ticked ones, as read
(@code{gnus-group-catchup-current-all}).   
@end table

@vindex gnus-large-newsgroup
The @code{gnus-large-newsgroup} variable says what Gnus should consider
to be a big group.  This is 200 by default.  If the group has more
unread articles than this, Gnus will query the user before entering the
group.  The user can then specify how many articles should be fetched
from the server.  If the user specifies a negative number (@code{-n}),
the @code{n} oldest articles will be fetched.  If it is positive, the
@code{n} articles that have arrived most recently will be fetched.

@vindex gnus-select-group-hook
@vindex gnus-auto-select-first
@code{gnus-auto-select-first} control whether any articles are selected
automatically when entering a group.  

@table @code

@item nil
Don't select any articles when entering the group.  Just display the
full summary buffer.

@item t
Select the first unread article when entering the group.  

@item best
Select the most high-scored article in the group when entering the
group. 
@end table
        
If you want to prevent automatic selection in some group (say, in a
binary group with Huge articles) you can set this variable to @code{nil}
in @code{gnus-select-group-hook}, which is called when a group is
selected.

@findex gnus-thread-sort-by-total-score
@findex gnus-thread-sort-by-date
@findex gnus-thread-sort-by-score
@findex gnus-thread-sort-by-subject
@findex gnus-thread-sort-by-author
@findex gnus-thread-sort-by-number
@vindex gnus-thread-sort-functions
If you are using a threaded summary display, you can sort the threads by
setting @code{gnus-thread-sort-functions}, which is a list of functions.
By default, sorting is done on article numbers.  Ready-made sorting
predicate functions include @code{gnus-thread-sort-by-number},
@code{gnus-thread-sort-by-author}, @code{gnus-thread-sort-by-subject},
@code{gnus-thread-sort-by-date}, @code{gnus-thread-sort-by-score}, and
@code{gnus-thread-sort-by-total-score}.

Each function takes two threads and return non-@code{nil} if the first
thread should be sorted before the other.  Note that sorting really is
normally done by looking only at the roots of each thread.  If you use
more than one function, the primary sort key should be the last function
in the list.  You should probably always include
@code{gnus-thread-sort-by-number} in the list of sorting
functions---preferably first.  This will ensure that threads that are
equal with respect to the other sort criteria will be displayed in
ascending article order.

If you would like to sort by score, then by subject, and finally by
number, you could do something like:

@lisp
(setq gnus-thread-sort-functions 
      '(gnus-thread-sort-by-number
        gnus-thread-sort-by-subject
        gnus-thread-sort-by-score))
@end lisp

The threads that have highest score will be displayed first in the
summary buffer.  When threads have the same score, they will be sorted
alphabetically.  The threads that have the same score and the same
subject will be sorted by number, which is (normally) the sequence in
which the articles arrived.

If you want to sort by score and then reverse arrival order, you could
say something like:

@lisp
(setq gnus-thread-sort-functions
      '((lambda (t1 t2) 
          (not (gnus-thread-sort-by-number t1 t2)))
        gnus-thread-sort-by-score))
@end lisp

@vindex gnus-thread-score-function
The function in the @code{gnus-thread-score-function} variable (default
@code{+}) is used for calculating the total score of a thread.  Useful
functions might be @code{max}, @code{min}, or squared means, or whatever
tickles your fancy.

@findex gnus-article-sort-functions
@findex gnus-article-sort-by-date
@findex gnus-article-sort-by-score
@findex gnus-article-sort-by-subject
@findex gnus-article-sort-by-author
@findex gnus-article-sort-by-number
If you are using an unthreaded display for some strange reason or other,
you have to fiddle with the @code{gnus-article-sort-functions} variable.
It is very similar to the @code{gnus-thread-sort-functions}, except that
is uses slightly different functions for article comparison.  Available
sorting predicate functions are @code{gnus-article-sort-by-number},
@code{gnus-article-sort-by-author}, @code{gnus-article-sort-by-subject},
@code{gnus-article-sort-by-date}, and @code{gnus-article-sort-by-score}.

If you want to sort an unthreaded summary display by subject, you could
say something like:

@lisp
(setq gnus-article-sort-functions 
      '(gnus-article-sort-by-number
        gnus-article-sort-by-subject))
@end lisp


@node Subscription Commands
@section Subscription Commands
@cindex subscribing

@table @kbd

@item S t
@itemx u
@kindex S t (Group)
@kindex u (Group)
@findex gnus-group-unsubscribe-current-group
Toggle subscription to the current group
(@code{gnus-group-unsubscribe-current-group}).  

@item S s
@itemx U
@kindex S s (Group)
@kindex U (Group)
@findex gnus-group-unsubscribe-group
Prompt for a group to subscribe, and then subscribe it.  If it was
subscribed already, unsubscribe it instead
(@code{gnus-group-unsubscribe-group}).

@item S k
@itemx C-k
@kindex S k (Group)
@kindex C-k (Group)
@findex gnus-group-kill-group
Kill the current group (@code{gnus-group-kill-group}).

@item S y
@itemx C-y
@kindex S y (Group)
@kindex C-y (Group)
@findex gnus-group-yank-group
Yank the last killed group (@code{gnus-group-yank-group}).

@item C-x C-t
@kindex C-x C-t (Group)
@findex gnus-group-transpose-groups
Transpose two groups (@code{gnus-group-transpose-groups}).  This isn't
really a subscription command, but you can use it instead of a
kill-and-yank sequence sometimes.

@item S w
@itemx C-w
@kindex S w (Group)
@kindex C-w (Group)
@findex gnus-group-kill-region
Kill all groups in the region (@code{gnus-group-kill-region}). 

@item S z
@kindex S z (Group)
@findex gnus-group-kill-all-zombies
Kill all zombie groups (@code{gnus-group-kill-all-zombies}).

@item S C-k
@kindex S C-k (Group)
@findex gnus-group-kill-level
Kill all groups on a certain level (@code{gnus-group-kill-level}).
These groups can't be yanked back after killing, so this command should
be used with some caution.  The only thing where this command comes in
really handy is when you have a @file{.newsrc} with lots of unsubscribed
groups that you want to get rid off.  @kbd{S C-k} on level @code{7} will
kill off all unsubscribed groups that do not have message numbers in the
@file{.newsrc} file.  

@end table

Also @pxref{Group Levels}.


@node Group Levels
@section Group Levels
@cindex group level

All groups have a level of @dfn{subscribedness}.  For instance, if a
group is on level 2, it is more subscribed than a group on level 5.  You
can ask Gnus to just list groups on a given level or lower
(@pxref{Listing Groups}), or to just check for new articles in groups on
a given level or lower (@pxref{Scanning New Messages}).

@table @kbd

@item S l
@kindex S l (Group)
@findex gnus-group-set-current-level
Set the level of the current group.  If a numeric prefix is given, the
next @var{n} groups will have their levels set.  The user will be
prompted for a level.
@end table

@vindex gnus-level-killed
@vindex gnus-level-zombie
@vindex gnus-level-unsubscribed
@vindex gnus-level-subscribed
Gnus considers groups on between levels 1 and
@code{gnus-level-subscribed} (inclusive) (default 5) to be subscribed,
@code{gnus-level-subscribed} (exclusive) and
@code{gnus-level-unsubscribed} (inclusive) (default 7) to be
unsubscribed, @code{gnus-level-zombie} to be zombies (walking dead)
(default 8) and @code{gnus-level-killed} to be killed (default 9),
completely dead.  Gnus treats subscribed and unsubscribed groups exactly
the same, but zombie and killed groups have no information on what
articles you have read, etc, stored.  This distinction between dead and
living groups isn't done because it is nice or clever, it is done purely
for reasons of efficiency.

It is recommended that you keep all your mail groups (if any) on quite
low levels (eg. 1 or 2).

If you want to play with the level variables, you should show some care.
Set them once, and don't touch them ever again.  Better yet, don't touch
them at all unless you know exactly what you're doing.

@vindex gnus-level-default-unsubscribed
@vindex gnus-level-default-subscribed
Two closely related variables are @code{gnus-level-default-subscribed}
(default 3) and @code{gnus-level-default-unsubscribed} (default 6),
which are the levels that new groups will be put on if they are
(un)subscribed.  These two variables should, of course, be inside the
relevant legal ranges.

@vindex gnus-keep-same-level
If @code{gnus-keep-same-level} is non-@code{nil}, some movement commands
will only move to groups that are of the same level (or lower).  In
particular, going from the last article in one group to the next group
will go to the next group of the same level (or lower).  This might be
handy if you want to read the most important groups before you read the
rest.

@vindex gnus-group-default-list-level
All groups with a level less than or equal to
@code{gnus-group-default-list-level} will be listed in the group buffer
by default.

@vindex gnus-group-list-inactive-groups
If @code{gnus-group-list-inactive-groups} is non-@code{nil}, non-active
groups will be listed along with the unread groups.  This variable is
@code{t} by default.  If it is @code{nil}, inactive groups won't be
listed. 

@vindex gnus-group-use-permanent-levels
If @code{gnus-group-use-permanent-levels} is non-@code{nil}, once you
give a level prefix to @kbd{g} or @kbd{l}, all subsequent commands will
use this level as the ``work'' level.

@vindex gnus-activate-level
Gnus will normally just activate groups that are on level
@code{gnus-activate-level} or less.  If you don't want to activate
unsubscribed groups, for instance, you might set this variable to
@code{5}. 


@node Group Score
@section Group Score
@cindex group score

You would normally keep important groups on high levels, but that scheme
is somewhat restrictive.  Don't you wish you could have Gnus sort the
group buffer according to how often you read groups, perhaps?  Within
reason?  

This is what @dfn{group score} is for.  You can assign a score to each
group.  You can then sort the group buffer based on this score.
Alternatively, you can sort on score and then level.  (Taken together,
the level and the score is called the @dfn{rank} of the group.  A group
that is on level 4 and has a score of 1 has a higher rank than a group
on level 5 that has a score of 300.  (The level is the most significant
part and the score is the least significant part.)

@findex gnus-summary-bubble-group
If you want groups you read often to get higher scores than groups you
read seldom you can add the @code{gnus-summary-bubble-group} function to
the @code{gnus-summary-exit-hook} hook.  This will result (after
sorting) in a bubbling sort of action.  If you want to see that in
action after each summary exit, you can add
@code{gnus-group-sort-groups-by-rank} or
@code{gnus-group-sort-groups-by-score} to the same hook, but that will
slow things down somewhat.


@node Marking Groups
@section Marking Groups
@cindex marking groups

If you want to perform some command on several groups, and they appear
subsequently in the group buffer, you would normally just give a
numerical prefix to the command.  Most group commands will then do your
bidding on those groups.

However, if the groups are not in sequential order, you can still
perform a command on several groups.  You simply mark the groups first
with the process mark and then execute the command.

@table @kbd

@item #
@kindex # (Group)
@itemx M m
@kindex M m (Group)
@findex gnus-group-mark-group
Set the mark on the current group (@code{gnus-group-mark-group}). 

@item M-#
@kindex M-# (Group)
@itemx M u
@kindex M u (Group)
@findex gnus-group-unmark-group
Remove the mark from the current group
(@code{gnus-group-unmark-group}). 

@item M U
@kindex M U (Group)
@findex gnus-group-unmark-all-groups
Remove the mark from all groups (@code{gnus-group-unmark-all-groups}). 

@item M w
@kindex M w (Group)
@findex gnus-group-mark-region
Mark all groups between point and mark (@code{gnus-group-mark-region}). 

@item M b
@kindex M b (Group)
@findex gnus-group-mark-buffer
Mark all groups in the buffer (@code{gnus-group-mark-buffer}). 

@item M r
@kindex M r (Group)
@findex gnus-group-mark-regexp
Mark all groups that match some regular expression
(@code{gnus-group-mark-regexp}).  
@end table

Also @pxref{Process/Prefix}.

@findex gnus-group-universal-argument
If you want to execute some command on all groups that have been marked
with the process mark, you can use the @kbd{M-&}
(@code{gnus-group-universal-argument}) command.  It will prompt you for
the command to be executed.


@node Foreign Groups
@section Foreign Groups

Here are some group mode commands for making and editing general foreign
groups, as well as commands to ease the creation of a few
special-purpose groups:

@table @kbd

@item G m
@kindex G m (Group)
@findex gnus-group-make-group
Make a new group (@code{gnus-group-make-group}).  Gnus will prompt you
for a name, a method and possibly an @dfn{address}.  For an easier way
to subscribe to @sc{nntp} groups, @pxref{Browse Foreign Server}.

@item G r
@kindex G r (Group)
@findex gnus-group-rename-group
Rename the current group to something else
(@code{gnus-group-rename-group}).  This is legal only on some groups --
mail groups mostly.  This command might very well be quite slow on some
backends. 

@item G e
@kindex G e (Group)
@findex gnus-group-edit-group-method
Enter a buffer where you can edit the select method of the current
group (@code{gnus-group-edit-group-method}).

@item G p
@kindex G p (Group)
@findex gnus-group-edit-group-parameters
Enter a buffer where you can edit the group parameters
(@code{gnus-group-edit-group-parameters}). 

@item G E
@kindex G E (Group)
@findex gnus-group-edit-group
Enter a buffer where you can edit the group info
(@code{gnus-group-edit-group}).

@item G d
@kindex G d (Group)
@findex gnus-group-make-directory-group
Make a directory group.  You will be prompted for a directory name
(@code{gnus-group-make-directory-group}).  

@item G h 
@kindex G h (Group)
@findex gnus-group-make-help-group
Make the Gnus help group (@code{gnus-group-make-help-group}).

@item G a
@kindex G a (Group)
@findex gnus-group-make-archive-group
@vindex gnus-group-archive-directory
@vindex gnus-group-recent-archive-directory
Make a Gnus archive group (@code{gnus-group-make-archive-group}).  By
default a group pointing to the most recent articles will be created
(@code{gnus-group-recent-archive-directory}), but given a prefix, a full
group will be created from from @code{gnus-group-archive-directory}.

@item G k
@kindex G k (Group)
@findex gnus-group-make-kiboze-group
Make a kiboze group.  You will be prompted for a name, for a regexp to
match groups to be ``included'' in the kiboze group, and a series of
strings to match on headers (@code{gnus-group-make-kiboze-group}).

@item G D
@kindex G D (Group)
@findex gnus-group-enter-directory
Read a random directory as if with were a newsgroup with the
@code{nneething} backend (@code{gnus-group-enter-directory}).

@item G f
@kindex G f (Group)
@findex gnus-group-make-doc-group
@cindex ClariNet Briefs
Make a group based on some file or other
(@code{gnus-group-make-doc-group}).  If you give a prefix to this
command, you will be prompted for a file name and a file type.
Currently supported types are @code{babyl}, @code{mbox}, @code{digest},
@code{mmdf}, @code{news}, @code{rnews}, @code{clari-briefs}, and
@code{forward}.  If you run this command without a prefix, Gnus will
guess at the file type.

@item G DEL
@kindex G DEL (Group)
@findex gnus-group-delete-group
This function will delete the current group
(@code{gnus-group-delete-group}).  If given a prefix, this function will
actually delete all the articles in the group, and forcibly remove the
group itself from the face of the Earth.  Use a prefix only if you are
absolutely sure of what you are doing.

@item G V
@kindex G V (Group)
@findex gnus-group-make-empty-virtual
Make a new, fresh, empty @code{nnvirtual} group
(@code{gnus-group-make-empty-virtual}).

@item G v
@kindex G v (Group)
@findex gnus-group-add-to-virtual
Add the current group to an @code{nnvirtual} group
(@code{gnus-group-add-to-virtual}).  Uses the process/prefix convention.
@end table

@xref{Select Methods} for more information on the various select
methods. 

@vindex gnus-activate-foreign-newsgroups
If the @code{gnus-activate-foreign-newsgroups} is a positive number,
Gnus will check all foreign groups with this level or lower at startup.
This might take quite a while, especially if you subscribe to lots of
groups from different @sc{nntp} servers.


@node Group Parameters
@section Group Parameters
@cindex group parameters

Gnus stores all information on a group in a list that is usually known
as the @dfn{group info}.  This list has from three to six elements.
Here's an example info.

@lisp
("nnml:mail.ding" 3 ((1 . 232) 244 (256 . 270)) ((tick 246 249))
                  (nnml "private") ((to-address . "ding@@ifi.uio.no")))
@end lisp

The first element is the @dfn{group name}, as Gnus knows the group,
anyway.  The second element is the @dfn{subscription level}, which
normally is a small integer.  The third element is a list of ranges of
read articles.  The fourth element is a list of lists of article marks
of various kinds.  The fifth element is the select method (or virtual
server, if you like).  The sixth element is a list of @dfn{group
parameters}, which is what this section is about.

Any of the last three elements may be missing if they are not required.
In fact, the vast majority of groups will normally only have the first
three elements, which saves quite a lot of cons cells.

The group parameters store information local to a particular group:

@table @code
@item to-address
@cindex to-address
If the group parameter list contains an element that looks like
@code{(to-address .  "some@@where.com")}, that address will be used by
the backend when doing followups and posts.  This is primarily useful in
mail groups that represent closed mailing lists---mailing lists where
it's expected that everybody that writes to the mailing list is
subscribed to it.  Since using this parameter ensures that the mail only
goes to the mailing list itself, it means that members won't receive two
copies of your followups.

Using @code{to-address} will actually work whether the group is foreign
or not.  Let's say there's a group on the server that is called
@samp{fa.4ad-l}.  This is a real newsgroup, but the server has gotten
the articles from a mail-to-news gateway.  Posting directly to this
group is therefore impossible---you have to send mail to the mailing
list address instead. 

@item to-list
@cindex to-list
If the group parameter list has an element that looks like
@code{(to-list . "some@@where.com")}, that address will be used when
doing a @kbd{a} in any group.  It is totally ignored when doing a
followup---except that if it is present in a news group, you'll get mail
group semantics when doing @kbd{f}.

@item broken-reply-to
@cindex broken-reply-to
Elements like @code{(broken-reply-to . t)} signals that @code{Reply-To}
headers in this group are to be ignored.  This can be useful if you're
reading a mailing list group where the listserv has inserted
@code{Reply-To} headers that point back to the listserv itself.  This is
broken behavior.  So there!

@item to-group
@cindex to-group
If the group parameter list contains an element like @code{(to-group
. "some.group.name")}, all posts will be sent to that group.

@item auto-expire
@cindex auto-expire
If this symbol is present in the group parameter list, all articles that
are read will be marked as expirable.  For an alternative approach,
@pxref{Expiring Mail}.

@item total-expire
@cindex total-expire
If this symbol is present, all read articles will be put through the
expiry process, even if they are not marked as expirable.  Use with
caution. 

@item expiry-wait
@cindex expiry-wait
@vindex nnmail-expiry-wait-function
If the group parameter has an element that looks like @code{(expiry-wait
. 10)}, this value will override any @code{nnmail-expiry-wait} and
@code{nnmail-expiry-wait-function} when expiring expirable messages.
The value can either be a number of days (not necessarily an integer) or
the symbols @code{never} or @code{immediate}.

@item score-file
Elements that look like @code{(score-file . "file")} will make
@samp{file} into the current score file for the group in question.  This
means that all score commands you issue will end up in that file. 

@item admin-address
When unsubscribing to a mailing list you should never send the
unsubscription notice to the mailing list itself.  Instead, you'd send
messages to the administrative address.  This parameter allows you to
put the admin address somewhere convenient.

@item comment
This parameter allows you to enter a random comment on the group.

@item @var{(variable form)}
You can use the group parameters to set variables local to the group you
are entering.  Say you want to turn threading off in
@samp{news.answers}.  You'd then put @code{(gnus-show-threads nil)} in
the group parameters of that group.  @code{gnus-show-threads} will be
made into a local variable in the summary buffer you enter, and the form
@code{nil} will be @code{eval}ed there.  

This can also be used as a group-specific hook function, if you'd like.
If you want to hear a beep when you enter the group
@samp{alt.binaries.pictures.furniture}, you could put something like
@code{(dummy-variable (ding))} in the parameters of that group.
@code{dummy-variable} will be set to the result of the @code{(ding)}
form, but who cares?

@end table

If you want to change the group info you can use the @kbd{G E} command
to enter a buffer where you can edit it.

You usually don't want to edit the entire group info, so you'd be better
off using the @kbd{G p} command to just edit the group parameters.


@node Listing Groups
@section Listing Groups
@cindex group listing

These commands all list various slices of the groups that are available.

@table @kbd

@item l
@itemx A s
@kindex A s (Group)
@kindex l (Group)
@findex gnus-group-list-groups
List all groups that have unread articles
(@code{gnus-group-list-groups}).  If the numeric prefix is used, this
command will list only groups of level ARG and lower.  By default, it
only lists groups of level five or lower (i.e., just subscribed groups).

@item L
@itemx A u
@kindex A u (Group)
@kindex L (Group)
@findex gnus-group-list-all-groups
List all groups, whether they have unread articles or not
(@code{gnus-group-list-all-groups}).  If the numeric prefix is used,
this command will list only groups of level ARG and lower.  By default,
it lists groups of level seven or lower (i.e., just subscribed and
unsubscribed groups).

@item A l
@kindex A l (Group)
@findex gnus-group-list-level
List all unread groups on a specific level
(@code{gnus-group-list-level}).  If given a prefix, also list the groups
with no unread articles.

@item A k
@kindex A k (Group)
@findex gnus-group-list-killed
List all killed groups (@code{gnus-group-list-killed}).  If given a
prefix argument, really list all groups that are available, but aren't
currently (un)subscribed.  This could entail reading the active file
from the server.

@item A z
@kindex A z (Group)
@findex gnus-group-list-zombies
List all zombie groups (@code{gnus-group-list-zombies}).

@item A m
@kindex A m (Group)
@findex gnus-group-list-matching
List all subscribed groups with unread articles that match a regexp
(@code{gnus-group-list-matching}). 

@item A M
@kindex A M (Group)
@findex gnus-group-list-all-matching
List groups that match a regexp (@code{gnus-group-list-all-matching}).

@item A A
@kindex A A (Group)
@findex gnus-group-list-active
List absolutely all groups that are in the active file(s) of the
server(s) you are connected to (@code{gnus-group-list-active}).  This
might very well take quite a while.  It might actually be a better idea
to do a @kbd{A m} to list all matching, and just give @samp{.} as the
thing to match on.

@item A a
@kindex A a (Group)
@findex gnus-group-apropos
List all groups that have names that match a regexp
(@code{gnus-group-apropos}).

@item A d
@kindex A d (Group)
@findex gnus-group-description-apropos
List all groups that have names or descriptions that match a regexp
(@code{gnus-group-description-apropos}).

@end table

@vindex gnus-permanently-visible-groups
@cindex visible group parameter
Groups that match the @code{gnus-permanently-visible-groups} regexp will
always be shown, whether they have unread articles or not.  You can also
add the @code{visible} element to the group parameters in question to
get the same effect.

@vindex gnus-list-groups-with-ticked-articles
Groups that have just ticked articles in it are normally listed in the
group buffer.  If @code{gnus-list-groups-with-ticked-articles} is
@code{nil}, these groups will be treated just like totally empty
groups.  It is @code{t} by default.


@node Sorting Groups
@section Sorting Groups
@cindex sorting groups

@kindex C-c C-s (Group)
@findex gnus-group-sort-groups
@vindex gnus-group-sort-function
The @kbd{C-c C-s} (@code{gnus-group-sort-groups}) command sorts the
group buffer according to the function(s) given by the
@code{gnus-group-sort-function} variable.  Available sorting functions
include: 

@table @code

@item gnus-group-sort-by-alphabet
@findex gnus-group-sort-by-alphabet
Sort the group names alphabetically.  This is the default.

@item gnus-group-sort-by-level
@findex gnus-group-sort-by-level
Sort by group level.

@item gnus-group-sort-by-score
@findex gnus-group-sort-by-score
Sort by group score.

@item gnus-group-sort-by-rank
@findex gnus-group-sort-by-rank
Sort by group score and then the group level.  The level and the score
are, when taken together, the group's @dfn{rank}. 

@item gnus-group-sort-by-unread
@findex gnus-group-sort-by-unread
Sort by number of unread articles.

@item gnus-group-sort-by-method
@findex gnus-group-sort-by-method
Sort by alphabetically on the select method.


@end table

@code{gnus-group-sort-function} can also be a list of sorting
functions.  In that case, the most significant sort key function must be
the last one.


There are also a number of commands for sorting directly according to
some sorting criteria:

@table @kbd
@item G S a
@kindex G S a (Group)
@findex gnus-group-sort-groups-by-alphabet
Sort the group buffer alphabetically by group name
(@code{gnus-group-sort-groups-by-alphabet}). 

@item G S u
@kindex G S u (Group)
@findex gnus-group-sort-groups-by-unread
Sort the group buffer by the number of unread articles
(@code{gnus-group-sort-groups-by-unread}).

@item G S l
@kindex G S l (Group)
@findex gnus-group-sort-groups-by-level
Sort the group buffer by group level
(@code{gnus-group-sort-groups-by-level}). 

@item G S v
@kindex G S v (Group)
@findex gnus-group-sort-groups-by-score
Sort the group buffer by group score
(@code{gnus-group-sort-groups-by-score}). 

@item G S r
@kindex G S r (Group)
@findex gnus-group-sort-groups-by-rank
Sort the group buffer by group level
(@code{gnus-group-sort-groups-by-rank}). 

@item G S m
@kindex G S m (Group)
@findex gnus-group-sort-groups-by-method
Sort the group buffer alphabetically by backend name
(@code{gnus-group-sort-groups-by-method}). 

@end table

When given a prefix, all these commands will sort in reverse order. 


@node Group Maintenance
@section Group Maintenance
@cindex bogus groups

@table @kbd
@item b
@kindex b (Group)
@findex gnus-group-check-bogus-groups
Find bogus groups and delete them
(@code{gnus-group-check-bogus-groups}).

@item F
@kindex F (Group)
@findex gnus-find-new-newsgroups
Find new groups and process them (@code{gnus-find-new-newsgroups}).  If
given a prefix, use the @code{ask-server} method to query the server for
new groups.

@item C-c C-x
@kindex C-c C-x (Group)
@findex gnus-group-expire-articles
Run all expirable articles in the current group through the expiry
process (if any) (@code{gnus-group-expire-articles}).

@item C-c M-C-x
@kindex C-c M-C-x (Group)
@findex gnus-group-expire-all-groups
Run all articles in all groups through the expiry process
(@code{gnus-group-expire-all-groups}).

@end table


@node Browse Foreign Server
@section Browse Foreign Server
@cindex foreign servers
@cindex browsing servers

@table @kbd
@item B
@kindex B (Group)
@findex gnus-group-browse-foreign-server
You will be queried for a select method and a server name.  Gnus will
then attempt to contact this server and let you browse the groups there
(@code{gnus-group-browse-foreign-server}).
@end table

@findex gnus-browse-server-mode
A new buffer with a list of available groups will appear.  This buffer
will be use the @code{gnus-browse-server-mode}.  This buffer looks a bit
(well, a lot) like a normal group buffer, but with one major difference
- you can't enter any of the groups.  If you want to read any of the
news available on that server, you have to subscribe to the groups you
think may be interesting, and then you have to exit this buffer.  The
new groups will be added to the group buffer, and then you can read them
as you would any other group.

Future versions of Gnus may possibly permit reading groups straight from
the browse buffer.

Here's a list of keystrokes available in the browse mode:

@table @kbd
@item n
@kindex n (Browse)
@findex gnus-group-next-group
Go to the next group (@code{gnus-group-next-group}).

@item p
@kindex p (Browse)
@findex gnus-group-prev-group
Go to the previous group (@code{gnus-group-prev-group}).

@item SPACE
@kindex SPACE (Browse)
@findex gnus-browse-read-group
Enter the current group and display the first article
(@code{gnus-browse-read-group}). 

@item RET
@kindex RET (Browse)
@findex gnus-browse-select-group
Enter the current group (@code{gnus-browse-select-group}). 

@item u
@kindex u (Browse)
@findex gnus-browse-unsubscribe-current-group
Unsubscribe to the current group, or, as will be the case here,
subscribe to it (@code{gnus-browse-unsubscribe-current-group}). 

@item l
@itemx q
@kindex q (Browse)
@kindex l (Browse)
@findex gnus-browse-exit
Exit browse mode (@code{gnus-browse-exit}).

@item ?
@kindex ? (Browse)
@findex gnus-browse-describe-briefly
Describe browse mode briefly (well, there's not much to describe, is
there) (@code{gnus-browse-describe-briefly}).
@end table


@node Exiting Gnus
@section Exiting Gnus
@cindex exiting Gnus

Yes, Gnus is ex(c)iting.

@table @kbd
@item z
@kindex z (Group)
@findex gnus-group-suspend
Suspend Gnus (@code{gnus-group-suspend}).  This doesn't really exit Gnus,
but it kills all buffers except the Group buffer.  I'm not sure why this
is a gain, but then who am I to judge?

@item q
@kindex q (Group)
@findex gnus-group-exit
Quit Gnus (@code{gnus-group-exit}).

@item Q
@kindex Q (Group)
@findex gnus-group-quit
Quit Gnus without saving any startup files (@code{gnus-group-quit}).
@end table

@vindex gnus-exit-gnus-hook
@vindex gnus-suspend-gnus-hook
@code{gnus-suspend-gnus-hook} is called when you suspend Gnus and
@code{gnus-exit-gnus-hook} is called when you quit Gnus, while
@code{gnus-after-exiting-gnus-hook} is called as the final item when
exiting Gnus.

@findex gnus-unload
@cindex unloading
If you wish to completely unload Gnus and all its adherents, you can use
the @code{gnus-unload} command.  This command is also very handy when
trying to customize meta-variables.

Note:

@quotation
Miss Lisa Cannifax, while sitting in English class, feels her feet go
numbly heavy and herself fall into a hazy trance as the boy sitting
behind her drew repeated lines with his pencil across the back of her
plastic chair.
@end quotation


@node Group Topics
@section Group Topics
@cindex topics

If you read lots and lots of groups, it might be convenient to group
them hierarchically according to topics.  You put your Emacs groups over
here, your sex groups over there, and the rest (what, two groups or so?)
you put in some misc section that you never bother with anyway.  You can
even group the Emacs sex groups as a sub-topic to either the Emacs
groups or the sex groups---or both!  Go wild!

@findex gnus-topic-mode
@kindex t (Group)
To get this @emph{fab} functionality you simply turn on (ooh!) the
@code{gnus-topic} minor mode---type @kbd{t} in the group buffer.  (This
is a toggling command.)

Go ahead, just try it.  I'll still be here when you get back.  La de
dum...  Nice tune, that...  la la la...  What, you're back? Yes, and now
press @kbd{l}.  There.  All your groups are now listed under
@samp{misc}.  Doesn't that make you feel all warm and fuzzy?  Hot and
bothered?

If you want this permanently enabled, you should add that minor mode to
the hook for the group mode:

@lisp
(add-hook 'gnus-group-mode-hook 'gnus-topic-mode)
@end lisp

@menu 
* Topic Variables::    How to customize the topics the Lisp Way.
* Topic Commands::     Interactive E-Z commands.
* Topic Topology::     A map of the world.
@end menu


@node Topic Variables
@subsection Topic Variables
@cindex topic variables

@vindex gnus-topic-unique
If @code{gnus-topic-unique} is non-@code{nil}, each group will be member
of (tops) one topic each.  If this is @code{nil}, each group might end
up being a member of several topics.

Now, if you select a topic, if will fold/unfold that topic, which is
really neat, I think.

@vindex gnus-topic-line-format
The topic lines themselves are created according to the
@code{gnus-topic-line-format} variable.  @xref{Formatting Variables}.
Elements allowed are:

@table @samp
@item i
Indentation.
@item n
Topic name.
@item v
Visibility.
@item l
Level.
@item g
Number of groups in the topic.
@item a
Number of unread articles in the topic.
@item A 
Number of unread articles in the topic and all its subtopics. 
@end table

@vindex gnus-topic-indent-level
Each sub-topic (and the groups in the sub-topics) will be indented with
@code{gnus-topic-indent-level} times the topic level number of spaces.
The default is @code{2}.

@vindex gnus-topic-mode-hook
@code{gnus-topic-mode-hook} is called in topic minor mode buffers. 


@node Topic Commands
@subsection Topic Commands
@cindex topic commands

When the topic minor mode is turned on, a new @kbd{T} submap will be
available.  In addition, a few of the standard keys change their
definitions slightly.

@table @kbd

@item T n
@kindex T n (Group)
@findex gnus-topic-create-topic
Create a new topic (@code{gnus-topic-create-topic}).  You will be
prompted for a topic name and the name of the parent topic.

@item T m
@kindex T m (Group)
@findex gnus-topic-move-group
Move the current group to some other topic
(@code{gnus-topic-move-group}).  This command understands the
process/prefix convention (@pxref{Process/Prefix}).

@item T c
@kindex T c (Group)
@findex gnus-topic-copy-group
Copy the current group to some other topic
(@code{gnus-topic-copy-group}).  This command understands the
process/prefix convention (@pxref{Process/Prefix}).

@item T D
@kindex T D (Group)
@findex gnus-topic-remove-group
Remove a group from the current topic (@code{gnus-topic-remove-group}).
This command understands the process/prefix convention
(@pxref{Process/Prefix}).

@item T M
@kindex T M (Group)
@findex gnus-topic-move-matching
Move all groups that match some regular expression to a topic
(@code{gnus-topic-move-matching}). 

@item T C
@kindex T C (Group)
@findex gnus-topic-copy-matching
Copy all groups that match some regular expression to a topic
(@code{gnus-topic-copy-matching}). 

@item T #
@kindex T # (Group)
@findex gnus-topic-mark-topic
Mark all groups in the current topic with the process mark
(@code{gnus-topic-mark-topic}). 

@item T M-#
@kindex T M-# (Group)
@findex gnus-topic-unmark-topic
Remove the process mark from all groups in the current topic
(@code{gnus-topic-unmark-topic}). 

@item RET
@kindex RET (Group)
@findex gnus-topic-select-group
@itemx SPACE
Either select a group or fold a topic (@code{gnus-topic-select-group}).
When you perform this command on a group, you'll enter the group, as
usual.  When done on a topic line, the topic will be folded (if it was
visible) or unfolded (if it was folded already).  So it's basically a
toggling command on topics.  In addition, if you give a numerical
prefix, group on that level (and lower) will be displayed.

@item T TAB
@kindex T TAB (Group)
@findex gnus-topic-indent
``Indent'' the current topic so that it becomes a sub-topic of the
previous topic (@code{gnus-topic-indent}).  If given a prefix,
``un-indent'' the topic instead.

@item C-k
@kindex C-k (Group)
@findex gnus-topic-kill-group
Kill a group or topic (@code{gnus-topic-kill-group}).  

@item C-y
@kindex C-y (Group)
@findex gnus-topic-yank-group
Yank the previously killed group or topic (@code{gnus-topic-yank-group}).
Note that all topics will be yanked before all groups.

@item T r
@kindex T r (Group)
@findex gnus-topic-rename
Rename a topic (@code{gnus-topic-rename}). 

@item T DEL
@kindex T DEL (Group)
@findex gnus-topic-delete
Delete an empty topic (@code{gnus-topic-delete}). 

@item A T
@kindex A T (Group)
@findex gnus-topic-list-active
List all groups that Gnus knows about in a topics-ified way
(@code{gnus-topic-list-active}).

@end table


@node Topic Topology
@subsection Topic Topology
@cindex topic topology
@cindex topology

So, let's have a look at an example group buffer:

@example
Gnus
  Emacs -- I wuw it!
       3: comp.emacs
       2: alt.religion.emacs
    Naughty Emacs
     452: alt.sex.emacs
       0: comp.talk.emacs.recovery
  Misc
       8: comp.binaries.fractals
      13: comp.sources.unix
@end example

So, here we have one top-level topic, two topics under that, and one
sub-topic under one of the sub-topics.  (There is always just one (1)
top-level topic).  This topology can be expressed as follows:

@lisp
(("Gnus" visible)
 (("Emacs -- I wuw it!" visible) 
  (("Naughty Emacs" visible)))
 (("Misc" visible)))
@end lisp

@vindex gnus-topic-topology
This is in fact how the variable @code{gnus-topic-topology} would look
for the display above.  That variable is saved in the @file{.newsrc.eld}
file, and shouldn't be messed with manually---unless you really want
to.  Since this variable is read from the @file{.newsrc.eld} file,
setting it in any other startup files will have no effect.  

This topology shows what topics are sub-topics of what topics (right),
and which topics are visible.  Two settings are currently
allowed---@code{visible} and @code{invisible}.


@node Misc Group Stuff
@section Misc Group Stuff

@menu
* Scanning New Messages:: Asking Gnus to see whether new messages have arrived.
* Group Information::     Information and help on groups and Gnus.
* File Commands::         Reading and writing the Gnus files.
@end menu

@table @kbd

@item ^
@kindex ^ (Group)
@findex gnus-group-enter-server-mode
Enter the server buffer (@code{gnus-group-enter-server-mode}). @xref{The
Server Buffer}.

@item a
@kindex a (Group)
@findex gnus-group-post-news
Post an article to a group (@code{gnus-group-post-news}).  The current
group name will be used as the default.

@item m
@kindex m (Group)
@findex gnus-group-mail
Mail a message somewhere (@code{gnus-group-mail}).

@end table

Variables for the group buffer:

@table @code

@item gnus-group-mode-hook
@vindex gnus-group-mode-hook
@code{gnus-group-mode-hook} is called after the group buffer has been
created. 

@item gnus-group-prepare-hook
@vindex gnus-group-prepare-hook
@code{gnus-group-prepare-hook} is called after the group buffer is
generated.  It may be used to modify the buffer in some strange,
unnatural way.

@end table


@node Scanning New Messages
@subsection Scanning New Messages
@cindex new messages
@cindex scanning new news

@table @kbd

@item g
@kindex g (Group)
@findex gnus-group-get-new-news
Check the server(s) for new articles.  If the numerical prefix is used,
this command will check only groups of level @var{arg} and lower
(@code{gnus-group-get-new-news}).  If given a non-numerical prefix, this
command will force a total rereading of the active file(s) from the
backend(s).

@item M-g
@kindex M-g (Group)
@findex gnus-group-get-new-news-this-group
@vindex gnus-goto-next-group-when-activating
Check whether new articles have arrived in the current group
(@code{gnus-group-get-new-news-this-group}).  The
@code{gnus-goto-next-group-when-activating} variable controls whether
this command is to move point to the next group or not.  It is @code{t}
by default.

@findex gnus-activate-all-groups
@cindex activating groups
@item C-c M-g
@kindex C-c M-g (Group)
Activate absolutely all groups (@code{gnus-activate-all-groups}). 

@item R
@kindex R (Group)
@cindex restarting
@findex gnus-group-restart
Restart Gnus (@code{gnus-group-restart}).

@end table

@vindex gnus-get-new-news-hook
@code{gnus-get-new-news-hook} is run just before checking for new news. 

@vindex gnus-after-getting-new-news-hook
@code{gnus-after-getting-new-news-hook} is run after checking for new
news.


@node Group Information
@subsection Group Information
@cindex group information
@cindex information on groups

@table @kbd

@item M-f
@kindex M-f (Group)
@findex gnus-group-fetch-faq
@cindex FAQ
@cindex ange-ftp
Try to fetch the FAQ for the current group
(@code{gnus-group-fetch-faq}).  Gnus will try to get the FAQ from
@code{gnus-group-faq-directory}, which is usually a directory on a
remote machine.  @code{ange-ftp} will be used for fetching the file.

@item D
@kindex D (Group)
@cindex describing groups
@cindex group description
@findex gnus-group-describe-group
Describe the current group (@code{gnus-group-describe-group}).  If given
a prefix, force Gnus to re-read the description from the server.

@item M-d
@kindex M-d (Group)
@findex gnus-group-describe-all-groups
Describe all groups (@code{gnus-group-describe-all-groups}).  If given a
prefix, force Gnus to re-read the description file from the server.

@item V
@kindex V (Group)
@cindex version
@findex gnus-version
Display current Gnus version numbers (@code{gnus-version}).

@item ?
@kindex ? (Group)
@findex gnus-group-describe-briefly
Give a very short help message (@code{gnus-group-describe-briefly}).

@item C-c C-i
@kindex C-c C-i (Group)
@cindex info
@cindex manual
@findex gnus-info-find-node
Go to the Gnus info node (@code{gnus-info-find-node}).
@end table


@node File Commands
@subsection File Commands
@cindex file commands

@table @kbd

@item r
@kindex r (Group)
@findex gnus-group-read-init-file
@vindex gnus-init-file
@cindex reading init file
Read the init file (@code{gnus-init-file}, which defaults to
@file{~/.gnus}) (@code{gnus-group-read-init-file}).

@item s
@kindex s (Group)
@findex gnus-group-save-newsrc
@cindex saving .newsrc
Save the @file{.newsrc.eld} file (and @file{.newsrc} if wanted)
(@code{gnus-group-save-newsrc}).  If given a prefix, force saving the
file(s) whether Gnus thinks it is necessary or not.

@item Z
@kindex Z (Group)
@findex gnus-group-clear-dribble
Clear the dribble buffer (@code{gnus-group-clear-dribble}).

@end table


@node The Summary Buffer
@chapter The Summary Buffer
@cindex summary buffer

A line for each article is displayed in the summary buffer.  You can
move around, read articles, post articles and reply to articles.

@menu
* Summary Buffer Format::       Deciding how the summary buffer is to look.
* Summary Maneuvering::         Moving around the summary buffer.
* Choosing Articles::           Reading articles.
* Paging the Article::          Scrolling the current article.
* Reply Followup and Post::     Posting articles.
* Canceling and Superseding::   ``Whoops, I shouldn't have called him that.''
* Marking Articles::            Marking articles as read, expirable, etc.
* Limiting::                    You can limit the summary buffer.
* Threading::                   How threads are made.
* Asynchronous Fetching::       Gnus might be able to pre-fetch articles.
* Article Caching::             You may store articles in a cache.
* Persistent Articles::         Making articles expiry-resistant.
* Article Backlog::             Having already read articles hang around.
* Saving Articles::             Ways of customizing article saving.
* Decoding Articles::           Gnus can treat series of (uu)encoded articles.
* Article Treatment::           The article buffer can be mangled at will.
* Summary Sorting::             Sorting the summary buffer in various ways.
* Finding the Parent::          No child support? Get the parent.
* Alternative Approaches::      Reading using non-default summaries.
* Tree Display::                A more visual display of threads.
* Mail Group Commands::         Some commands can only be used in mail groups.
* Various Summary Stuff::       What didn't fit anywhere else.
* Exiting the Summary Buffer::  Returning to the Group buffer.
@end menu


@node Summary Buffer Format
@section Summary Buffer Format
@cindex summary buffer format

@menu
* Summary Buffer Lines::     You can specify how summary lines should look.
* Summary Buffer Mode Line:: You can say how the mode line should look.
* Summary Highlighting::     Making the summary buffer all pretty and nice.
@end menu

@findex mail-extract-address-components
@findex gnus-extract-address-components
@vindex gnus-extract-address-components
Gnus will use the value of the @code{gnus-extract-address-components}
variable as a function for getting the name and address parts of a
@code{From} header.  Two pre-defined function exist:
@code{gnus-extract-address-components}, which is the default, quite
fast, and too simplistic solution; and
@code{mail-extract-address-components}, which works very nicely, but is
slower.

@vindex gnus-summary-same-subject
@code{gnus-summary-same-subject} is a string indicating that the current
article has the same subject as the previous.  This string will be used
with those specs that require it.  The default is @samp{}.


@node Summary Buffer Lines
@subsection Summary Buffer Lines

@vindex gnus-summary-line-format
You can change the format of the lines in the summary buffer by changing
the @code{gnus-summary-line-format} variable.  It works along the same
lines a a normal @code{format} string, with some extensions.

The default string is @samp{%U%R%z%I%(%[%4L: %-20,20n%]%) %s\n}.

The following format specification characters are understood:

@table @samp
@item N 
Article number.
@item S
Subject string.
@item s
Subject if the article is the root, @code{gnus-summary-same-subject}
otherwise. 
@item F
Full @code{From} line.
@item n
The name (from the @code{From} header).
@item a
The name (from the @code{From} header).  This differs from the @code{n}
spec in that it uses @code{gnus-extract-address-components}, which is
slower, but may be more thorough.
@item A
The address (from the @code{From} header).  This works the same way as
the @code{a} spec.
@item L
Number of lines in the article.
@item c
Number of characters in the article.
@item I
Indentation based on thread level (@pxref{Customizing Threading}).
@item T
Nothing if the article is a root and lots of spaces if it isn't (it
pushes everything after it off the screen).
@item \[
Opening bracket, which is normally @samp{\[}, but can also be @samp{<}
for adopted articles.
@item \]
Closing bracket, which is normally @samp{\]}, but can also be @samp{>}
for adopted articles.
@item >
One space for each thread level.
@item <
Twenty minus thread level spaces.
@item U
Unread.
@item R
Replied.
@item i
Score as a number.
@item z
@vindex gnus-summary-zcore-fuzz
Zcore, @samp{+} if above the default level and @samp{-} if below the
default level.  If the difference between
@code{gnus-summary-default-level} and the score is less than
@code{gnus-summary-zcore-fuzz}, this spec will not be used.
@item V
Total thread score.
@item x
@code{Xref}.
@item D
@code{Date}.
@item M
@code{Message-ID}.
@item r
@code{References}.
@item t
Number of articles in the current sub-thread.  Using this spec will slow
down summary buffer generation somewhat.
@item e
A single character will be displayed if the article has any children. 
@item u
User defined specifier.  The next character in the format string should
be a letter.  @sc{gnus} will call the function
@code{gnus-user-format-function-}@samp{X}, where @samp{X} is the letter
following @samp{%u}.  The function will be passed the current header as
argument.  The function should return a string, which will be inserted
into the summary just like information from any other summary specifier.
@end table

The @samp{%U} (status), @samp{%R} (replied) and @samp{%z} (zcore) specs
have to be handled with care.  For reasons of efficiency, Gnus will
compute what column these characters will end up in, and ``hard-code''
that.  This means that it is illegal to have these specs after a
variable-length spec.  Well, you might not be arrested, but your summary
buffer will look strange, which is bad enough.

The smart choice is to have these specs as far to the left as possible.
(Isn't that the case with everything, though?  But I digress.)

This restriction may disappear in later versions of Gnus.


@node Summary Buffer Mode Line
@subsection Summary Buffer Mode Line

@vindex gnus-summary-mode-line-format
You can also change the format of the summary mode bar.  Set
@code{gnus-summary-mode-line-format} to whatever you like.  Here are the
elements you can play with:

@table @samp
@item G
Group name.
@item p
Unprefixed group name.
@item A
Current article number.
@item V
Gnus version.
@item U
Number of unread articles in this group.
@item e
Number of unselected articles in this group.
@item Z
A string with the number of unread and unselected articles represented
either as @samp{<%U(+%u) more>} if there are both unread and unselected
articles, and just as @samp{<%U more>} if there are just unread articles
and no unselected ones.
@item g
Shortish group name.  For instance, @samp{rec.arts.anime} will be
shortened to @samp{r.a.anime}. 
@item S
Subject of the current article.
@item u
Used-defined spec.
@item s
Name of the current score file.
@item d
Number of dormant articles.
@item t
Number of ticked articles.
@item r
Number of articles that have been marked as read in this session. 
@item E
Number of articles expunged by the score files.
@end table


@node Summary Highlighting
@subsection Summary Highlighting

@table @code

@item gnus-visual-mark-article-hook
@vindex gnus-visual-mark-article-hook
This hook is run after selecting an article.  It is meant to be used for
highlighting the article in some way.  It is not run if
@code{gnus-visual} is @code{nil}.

@item gnus-summary-update-hook
@vindex gnus-summary-update-hook
This hook is called when a summary line is changed.  It is not run if
@code{gnus-visual} is @code{nil}.

@item gnus-summary-selected-face
@vindex gnus-summary-selected-face
This is the face (or @dfn{font} as some people call it) that is used to
highlight the current article in the summary buffer.

@item gnus-summary-highlight
@vindex gnus-summary-highlight
Summary lines are highlighted according to this variable, which is a
list where the elements are on the format @code{(FORM . FACE)}.  If you
would, for instance, like ticked articles to be italic and high-scored
articles to be bold, you could set this variable to something like
@lisp
(((eq mark gnus-ticked-mark) . italic)
 ((> score default) . bold))
@end lisp
As you may have guessed, if @var{FORM} returns a non-@code{nil} value,
@var{FACE} will be applied to the line.
@end table


@node Summary Maneuvering
@section Summary Maneuvering
@cindex summary movement

All the straight movement commands understand the numeric prefix and
behave pretty much as you'd expect. 

None of these commands select articles.

@table @kbd
@item G M-n
@itemx M-n
@kindex M-n (Summary)
@kindex G M-n (Summary)
@findex gnus-summary-next-unread-subject
Go to the next summary line of an unread article
(@code{gnus-summary-next-unread-subject}). 

@item G M-p
@itemx M-p
@kindex M-p (Summary)
@kindex G M-p (Summary)
@findex gnus-summary-prev-unread-subject
Go to the previous summary line of an unread article
(@code{gnus-summary-prev-unread-subject}). 

@item G j
@itemx j
@kindex j (Summary)
@kindex G j (Summary)
@findex gnus-summary-goto-article
Ask for an article number and then go that article
(@code{gnus-summary-goto-article}). 

@item G g
@kindex G g (Summary)
@findex gnus-summary-goto-subject
Ask for an article number and then go the summary line of that article
(@code{gnus-summary-goto-subject}).
@end table

If Gnus asks you to press a key to confirm going to the next group, you
can use the @kbd{C-n} and @kbd{C-p} keys to move around the group
buffer, searching for the next group to read without actually returning
to the group buffer.

Variables related to summary movement:

@table @code

@vindex gnus-auto-select-next
@item gnus-auto-select-next
If you are at the end of the group and issue one of the movement
commands, Gnus will offer to go to the next group.  If this variable is
@code{t} and the next group is empty, Gnus will exit summary mode and
return to the group buffer.  If this variable is neither @code{t} nor
@code{nil}, Gnus will select the next group, no matter whether it has
any unread articles or not.  As a special case, if this variable is
@code{quietly}, Gnus will select the next group without asking for
confirmation.  If this variable is @code{almost-quietly}, the same will
happen only if you are located on the last article in the group.
Finally, if this variable is @code{slightly-quietly}, the @kbd{Z n}
command will go to the next group without confirmation.  Also
@pxref{Group Levels}.

@item gnus-auto-select-same
@vindex gnus-auto-select-same
If non-@code{nil}, all the movement commands will try to go to the next
article with the same subject as the current.  This variable is not
particularly useful if you use a threaded display.

@item gnus-summary-check-current
@vindex gnus-summary-check-current
If non-@code{nil}, all the ``unread'' movement commands will not proceed
to the next (or previous) article if the current article is unread.
Instead, they will choose the current article.

@item gnus-auto-center-summary
@vindex gnus-auto-center-summary
If non-@code{nil}, Gnus will keep the point in the summary buffer
centered at all times.  This makes things quite tidy, but if you have a
slow network connection, or simply do not like this un-Emacsism, you can
set this variable to @code{nil} to get the normal Emacs scrolling
action.  This will also inhibit horizontal re-centering of the summary
buffer, which might make it more inconvenient to read extremely long
threads.

@end table


@node Choosing Articles
@section Choosing Articles
@cindex selecting articles

None of the following movement commands understand the numeric prefix,
and they all select and display an article.

@table @kbd
@item SPACE
@kindex SPACE (Summary)
@findex gnus-summary-next-page
Select the current article, or, if that one's read already, the next
unread article (@code{gnus-summary-next-page}).

@item G n
@itemx n
@kindex n (Summary)
@kindex G n (Summary)
@findex gnus-summary-next-unread-article
Go to next unread article (@code{gnus-summary-next-unread-article}).

@item G p
@itemx p
@kindex p (Summary)
@findex gnus-summary-prev-unread-article
Go to previous unread article (@code{gnus-summary-prev-unread-article}).

@item G N
@itemx N
@kindex N (Summary)
@kindex G N (Summary)
@findex gnus-summary-next-article
Go to the next article (@code{gnus-summary-next-article}).

@item G P
@itemx P
@kindex P (Summary)
@kindex G P (Summary)
@findex gnus-summary-prev-article
Go to the previous article (@code{gnus-summary-prev-article}).

@item G C-n
@kindex G C-n (Summary)
@findex gnus-summary-next-same-subject
Go to the next article with the same subject
(@code{gnus-summary-next-same-subject}). 

@item G C-p
@kindex G C-p (Summary)
@findex gnus-summary-prev-same-subject
Go to the previous article with the same subject
(@code{gnus-summary-prev-same-subject}). 

@item G f
@itemx .
@kindex G f  (Summary)
@kindex .  (Summary)
@findex gnus-summary-first-unread-article
Go to the first unread article
(@code{gnus-summary-first-unread-article}).

@item G b
@itemx ,
@kindex G b (Summary)
@kindex , (Summary)
@findex gnus-summary-best-unread-article
Go to the article with the highest score
(@code{gnus-summary-best-unread-article}). 

@item G l
@itemx l
@kindex l (Summary)
@kindex G l (Summary)
@findex gnus-summary-goto-last-article
Go to the previous article read (@code{gnus-summary-goto-last-article}).

@item G p
@kindex G p (Summary)
@findex gnus-summary-pop-article
Pop an article off the summary history and go to this article
(@code{gnus-summary-pop-article}).  This command differs from the
command above in that you can pop as many previous articles off the
history as you like.
@end table

Some variables that are relevant for moving and selecting articles:

@table @code
@item gnus-auto-extend-newsgroup
@vindex gnus-auto-extend-newsgroup
All the movement commands will try to go to the previous (or next)
article, even if that article isn't displayed in the Summary buffer if
this variable is non-@code{nil}.  Gnus will then fetch the article from
the server and display it in the article buffer.

@item gnus-select-article-hook
@vindex gnus-select-article-hook
This hook is called whenever an article is selected.  By default it
exposes any threads hidden under the selected article.

@item gnus-mark-article-hook
@vindex gnus-mark-article-hook
@findex gnus-summary-mark-unread-as-read
@findex gnus-summary-mark-read-and-unread-as-read
@findex gnus-unread-mark
This hook is called whenever an article is selected.  It is intended to
be used for marking articles as read.  The default value is
@code{gnus-summary-mark-unread-and-read-as-read}, and will change the
mark of almost any article you read to @code{gnus-unread-mark}.  The
only articles not affected by this function are ticked, dormant, and
expirable articles.  If you'd instead like to just have unread articles
marked as read, you can use @code{gnus-summary-mark-unread-as-read}
instead.  It will leave marks like @code{gnus-low-score-mark},
@code{gnus-del-mark} (and so on) alone.

@end table


@node Paging the Article
@section Scrolling the Article
@cindex article scrolling

@table @kbd

@item SPACE
@kindex SPACE (Summary)
@findex gnus-summary-next-page
Pressing @kbd{SPACE} will scroll the current article forward one page,
or, if you have come to the end of the current article, will choose the
next article (@code{gnus-summary-next-page}).

@item DEL
@kindex DEL (Summary)
@findex gnus-summary-prev-page
Scroll the current article back one page (@code{gnus-summary-prev-page}). 

@item RET
@kindex RET (Summary)
@findex gnus-summary-scroll-up
Scroll the current article one line forward
(@code{gnus-summary-scroll-up}).

@item A <
@itemx <
@kindex < (Summary)
@kindex A < (Summary)
@findex gnus-summary-beginning-of-article
Scroll to the beginning of the article
(@code{gnus-summary-beginning-of-article}).

@item A >
@itemx >
@kindex > (Summary)
@kindex A > (Summary)
@findex gnus-summary-end-of-article
Scroll to the end of the article (@code{gnus-summary-end-of-article}).

@item A s 
@kindex A s (Summary)
@findex gnus-summary-isearch-article
Perform an isearch in the article buffer
(@code{gnus-summary-isearch-article}). 

@end table


@node Reply Followup and Post
@section Reply, Followup and Post

@menu
* Summary Mail Commands::            Sending mail.
* Summary Post Commands::            Sending news.
* Summary Mail and Post Commands::   Sending both news and mail.
@end menu


@node Summary Mail Commands
@subsection Summary Mail Commands
@cindex mail
@cindex composing mail

Commands for composing a mail message:

@table @kbd

@item S r
@itemx r
@kindex S r (Summary)
@kindex r (Summary)
@findex gnus-summary-reply
Mail a reply to the author of the current article
(@code{gnus-summary-reply}). 

@item S R
@itemx R
@kindex R (Summary)
@kindex S R (Summary)
@findex gnus-summary-reply-with-original
Mail a reply to the author of the current article and include the
original message (@code{gnus-summary-reply-with-original}).  This
command uses the process/prefix convention.

@item S o m
@kindex S o m (Summary)
@findex gnus-summary-mail-forward
Forward the current article to some other person
(@code{gnus-summary-mail-forward}). 

@item S o p
@kindex S o p (Summary)
@findex gnus-summary-post-forward
Forward the current article to a newsgroup
(@code{gnus-summary-post-forward}).

@item S m
@itemx m
@kindex m (Summary)
@kindex S m (Summary)
@findex gnus-summary-mail-other-window
Send a mail to some other person
(@code{gnus-summary-mail-other-window}).

@item S D b
@kindex S D b (Summary)
@findex gnus-summary-resend-bounced-mail
@vindex gnus-bounced-headers-junk
@cindex bouncing mail
If you have sent a mail, but the mail was bounced back to you for some
reason (wrong address, transient failure), you can use this command to
resend that bounced mail (@code{gnus-summary-resend-bounced-mail}).  You
will be popped into a mail buffer where you can edit the headers before
sending the mail off again.  The headers that match the regexp
@code{gnus-bounced-headers-junk} (default @samp{^Received:}) are
automatically deleted first.  If you give a prefix to this command, and
the bounced mail is a reply to some other mail, Gnus will try to fetch
that mail and display it for easy perusal of its headers.  This might
very well fail, though.

@item S D r
@kindex S D r (Summary)
@findex gnus-summary-resend-message
@vindex gnus-ignored-resent-headers
Not to be confused with the previous command,
@code{gnus-summary-resend-message} will prompt you for an address to
send the current message off to, and then send it to that place.  The
headers of the message won't be altered---but lots of headers that say
@code{Resent-To}, @code{Resent-From} and so on will be added.  This
means that you actually send a mail to someone that has a @code{To}
header that (probably) points to yourself.  This will confuse people.
So, natcherly you'll only do that if you're really eVIl.  All old
headers that match the regular expression
@code{gnus-ignored-resent-headers} will be deleted before resending the
message.  The default is @samp{"^Return-receipt"}.

This command is mainly used if you have several accounts and want to
ship a mail to a different account of yours.  (If you're both
@code{root} and @code{postmaster} and get a mail for @code{postmaster}
to the @code{root} account, you may want to resend it to
@code{postmaster}.  Ordnung muss sein!

@item S O m
@kindex S O m (Summary)
@findex gnus-uu-digest-mail-forward
Digest the current series and forward the result using mail
(@code{gnus-uu-digest-mail-forward}).  This command uses the
process/prefix convention (@pxref{Process/Prefix}). 

@item S O p
@kindex S O p (Summary)
@findex gnus-uu-digest-post-forward
Digest the current series and forward the result to a newsgroup
(@code{gnus-uu-digest-mail-forward}).  
@end table


@node Summary Post Commands
@subsection Summary Post Commands
@cindex post
@cindex composing news

Commands for posting an article:

@table @kbd
@item S p
@itemx a
@kindex a (Summary)
@kindex S p (Summary)
@findex gnus-summary-post-news
Post an article to the current group
(@code{gnus-summary-post-news}).

@item S f
@itemx f
@kindex f (Summary)
@kindex S f (Summary)
@findex gnus-summary-followup
Post a followup to the current article (@code{gnus-summary-followup}).

@item S F
@itemx F
@kindex S F (Summary)
@kindex F (Summary)
@findex gnus-summary-followup-with-original
Post a followup to the current article and include the original message
(@code{gnus-summary-followup-with-original}).   This command uses the
process/prefix convention.

@item S u
@kindex S u (Summary)
@findex gnus-uu-post-news
Uuencode a file, split it into parts, and post it as a series
(@code{gnus-uu-post-news}). (@pxref{Uuencoding and Posting}). 
@end table


@node Summary Mail and Post Commands
@subsection Summary Mail and Post Commands
@cindex mail and post
@cindex post and mail

Commands for sending mail and post at the same time:

@table @kbd
@item S b
@kindex S b (Summary)
@findex gnus-summary-followup-and-reply
Post a followup and send a reply to the current article
(@code{gnus-summary-followup-and-reply}).

@item S B
@kindex S B (Summary)
@findex gnus-summary-followup-and-reply-with-original
Post a followup and send a reply to the current article and include the
original message (@code{gnus-summary-followup-and-reply-with-original}).
This command uses the process/prefix convention.
@end table


@node Canceling and Superseding
@section Canceling Articles
@cindex canceling articles
@cindex superseding articles

Have you ever written something, and then decided that you really,
really, really wish you hadn't posted that?

Well, you can't cancel mail, but you can cancel posts.

@findex gnus-summary-cancel-article
@kindex C (Summary)
Find the article you wish to cancel (you can only cancel your own
articles, so don't try any funny stuff).  Then press @kbd{C} or @kbd{S
c} (@code{gnus-summary-cancel-article}).  Your article will be
canceled---machines all over the world will be deleting your article. 

Be aware, however, that not all sites honor cancels, so your article may
live on here and there, while most sites will delete the article in
question.

If you discover that you have made some mistakes and want to do some
corrections, you can post a @dfn{superseding} article that will replace
your original article.

@findex gnus-summary-supersede-article
@kindex S (Summary)
Go to the original article and press @kbd{S s}
(@code{gnus-summary-supersede-article}).  You will be put in a buffer
where you can edit the article all you want before sending it off the
usual way.

@vindex gnus-delete-supersedes-headers
You probably want to delete some of the old headers before sending the
superseding article---@code{Path} and @code{Date} are probably
incorrect.  Set @code{gnus-delete-supersedes-headers} to a regexp to
match the lines you want removed.  The default is
@samp{^Path:\\|^Date}. 

The same goes for superseding as for canceling, only more so: Some
sites do not honor superseding.  On those sites, it will appear that you
have posted almost the same article twice.

If you have just posted the article, and change your mind right away,
there is a trick you can use to cancel/supersede the article without
waiting for the article to appear on your site first.  You simply return
to the post buffer (which is called @code{*post-buf*}).  There you will
find the article you just posted, with all the headers intact.  Change
the @code{Message-ID} header to a @code{Cancel} or @code{Supersedes}
header by substituting one of those words for @code{Message-ID}.  Then
just press @kbd{C-c C-c} to send the article as you would do normally.
The previous article will be canceled/superseded.

Just remember, kids: There is no 'c' in 'supersede'.


@node Marking Articles
@section Marking Articles
@cindex article marking
@cindex article ticking
@cindex marks

There are several marks you can set on an article. 

You have marks that decide the @dfn{readedness} (whoo, neato-keano
neologism ohoy!) of the article.  Alphabetic marks generally mean
@dfn{read}, while non-alphabetic characters generally mean @dfn{unread}.

In addition, you also have marks that do not affect readedness.

@menu
* Unread Articles::      Marks for unread articles.
* Read Articles::        Marks for read articles.
* Other Marks::          Marks that do not affect readedness.
@end menu

@ifinfo
There's a plethora of commands for manipulating these marks:
@end ifinfo

@menu
* Setting Marks::           How to set and remove marks.
* Setting Process Marks::   How to mark articles for later processing.
@end menu


@node Unread Articles
@subsection Unread Articles

The following marks mark articles as unread, in one form or other.

@vindex gnus-dormant-mark
@vindex gnus-ticked-mark
@table @samp
@item !
@dfn{Ticked articles} are articles that will remain visible always.  If
you see an article that you find interesting, or you want to put off
reading it, or replying to it, until sometime later, you'd typically
tick it.  However, articles can be expired, so if you want to keep an
article forever, you'll have to save it.  Ticked articles have a
@samp{!} (@code{gnus-ticked-mark}) in the first column.

@item ?
@vindex gnus-dormant-mark
A @dfn{dormant} article is marked with a @samp{?}
(@code{gnus-dormant-mark}), and will only appear in the summary buffer
if there are followups to it.

@item SPACE
@vindex gnus-unread-mark
An @dfn{unread} article is marked with a @samp{SPACE}
(@code{gnus-unread-mark}).  These are articles that haven't been read at
all yet.
@end table


@node Read Articles
@subsection Read Articles
@cindex expirable mark

All the following marks mark articles as read.

@table @samp

@item r
@vindex gnus-del-mark
Articles that are marked as read.  They have a @samp{r}
(@code{gnus-del-mark}) in the first column.  These are articles that the
user has marked as read more or less manually.

@item R
@vindex gnus-read-mark
Articles that are actually read are marked with @samp{R}
(@code{gnus-read-mark}). 

@item O
@vindex gnus-ancient-mark
Articles that were marked as read in previous sessions are now
@dfn{old} and marked with @samp{O} (@code{gnus-ancient-mark}). 

@item K
@vindex gnus-killed-mark
Marked as killed (@code{gnus-killed-mark}).

@item X
@vindex gnus-kill-file-mark
Marked as killed by kill files (@code{gnus-kill-file-mark}).

@item Y
@vindex gnus-low-score-mark
Marked as read by having a too low score (@code{gnus-low-score-mark}).

@item C
@vindex gnus-catchup-mark
Marked as read by a catchup (@code{gnus-catchup-mark}).

@item G
@vindex gnus-canceled-mark
Canceled article (@code{gnus-canceled-mark})

@item F
@vindex gnus-souped-mark
@sc{SOUP}ed article (@code{gnus-souped-mark}).

@item Q
@vindex gnus-sparse-mark
Sparsely reffed article (@code{gnus-sparse-mark}).
@end table

All these marks just mean that the article is marked as read, really.
They are interpreted differently by the adaptive scoring scheme,
however.

One more special mark, though:

@table @samp
@item E
@vindex gnus-expirable-mark
You can also mark articles as @dfn{expirable} (or have them marked as
such automatically).  That doesn't make much sense in normal groups,
because a user does not control the expiring of news articles, but in
mail groups, for instance, articles that are marked as @dfn{expirable}
can be deleted by Gnus at any time.  Expirable articles are marked with
@samp{E} (@code{gnus-expirable-mark}).
@end table


@node Other Marks
@subsection Other Marks
@cindex process mark
@cindex bookmarks

There are some marks that have nothing to do with whether the article is
read or not.

@itemize @bullet

@item 
You can set a bookmark in the current article.  Say you are reading a
long thesis on cats' urinary tracts, and have to go home for dinner
before you've finished reading the thesis.  You can then set a bookmark
in the article, and Gnus will jump to this bookmark the next time it
encounters the article.

@item
@vindex gnus-replied-mark
All articles that you have replied to or made a followup to (i.e., have
answered) will be marked with an @samp{A} in the second column
(@code{gnus-replied-mark}).

@item 
@vindex gnus-cached-mark
Articles that are stored in the article cache will be marked with an
@samp{*} in the second column (@code{gnus-cached-mark}).

@item 
@vindex gnus-saved-mark
Articles that are ``saved'' (in some manner or other; not necessarily
religiously) are marked with an @samp{S} in the second column
(@code{gnus-saved-mark}.

@item 
@vindex gnus-not-empty-thread-mark
@vindex gnus-empty-thread-mark
It the @samp{%e} spec is used, the presence of threads or not will be
marked with @code{gnus-not-empty-thread-mark} and
@code{gnus-empty-thread-mark} in the third column, respectively.

@item 
@vindex gnus-process-mark
Finally we have the @dfn{process mark} (@code{gnus-process-mark}.  A
variety of commands react to the presence of the process mark.  For
instance, @kbd{X u} (@code{gnus-uu-decode-uu}) will uudecode and view
all articles that have been marked with the process mark.  Articles
marked with the process mark have a @samp{#} in the second column.

@end itemize

You might have noticed that most of these ``non-readedness'' marks
appear in the second column by default.  So if you have a cached, saved,
replied article that you have process-marked, what will that look like?

Nothing much.  The precedence rules go as follows: process -> cache ->
replied -> saved.  So if the article is in the cache and is replied,
you'll only see the cache mark and not the replied mark.


@node Setting Marks
@subsection Setting Marks
@cindex setting marks

All the marking commands understand the numeric prefix.

@table @kbd
@item M t
@itemx !
@kindex ! (Summary)
@kindex M t (Summary)
@findex gnus-summary-tick-article-forward
Tick the current article (@code{gnus-summary-tick-article-forward}).

@item M ?
@itemx ?
@kindex ? (Summary)
@kindex M ? (Summary)
@findex gnus-summary-mark-as-dormant
Mark the current article as dormant
(@code{gnus-summary-mark-as-dormant}).

@item M d
@itemx d
@kindex M d (Summary)
@kindex d (Summary)
@findex gnus-summary-mark-as-read-forward
Mark the current article as read
(@code{gnus-summary-mark-as-read-forward}).

@item M k
@itemx k
@kindex k (Summary)
@kindex M k (Summary)
@findex gnus-summary-kill-same-subject-and-select
Mark all articles that have the same subject as the current one as read,
and then select the next unread article
(@code{gnus-summary-kill-same-subject-and-select}).

@item M K
@itemx C-k
@kindex M K (Summary)
@kindex C-k (Summary)
@findex gnus-summary-kill-same-subject
Mark all articles that have the same subject as the current one as read
(@code{gnus-summary-kill-same-subject}).  

@item M C
@kindex M C (Summary)
@findex gnus-summary-catchup
Mark all unread articles in the group as read
(@code{gnus-summary-catchup}).

@item M C-c
@kindex M C-c (Summary)
@findex gnus-summary-catchup-all
Mark all articles in the group as read---even the ticked and dormant
articles (@code{gnus-summary-catchup-all}).

@item M H
@kindex M H (Summary)
@findex gnus-summary-catchup-to-here
Catchup the current group to point
(@code{gnus-summary-catchup-to-here}). 

@item C-w
@kindex C-w (Summary)
@findex gnus-summary-mark-region-as-read
Mark all articles between point and mark as read
(@code{gnus-summary-mark-region-as-read}). 

@item M V k
@kindex M V k (Summary)
@findex gnus-summary-kill-below
Kill all articles with scores below the default score (or below the
numeric prefix) (@code{gnus-summary-kill-below}).

@item M c
@itemx M-u
@kindex M c (Summary)
@kindex M-u (Summary)
@findex gnus-summary-clear-mark-forward
Clear all readedness-marks from the current article
(@code{gnus-summary-clear-mark-forward}).

@item M e
@itemx E
@kindex M e (Summary)
@kindex E (Summary)
@findex gnus-summary-mark-as-expirable
Mark the current article as expirable
(@code{gnus-summary-mark-as-expirable}).

@item M b
@kindex M b (Summary)
@findex gnus-summary-set-bookmark
Set a bookmark in the current article
(@code{gnus-summary-set-bookmark}).

@item M B
@kindex M B (Summary)
@findex gnus-summary-remove-bookmark
Remove the bookmark from the current article
(@code{gnus-summary-remove-bookmark}).

@item M V c
@kindex M V c (Summary)
@findex gnus-summary-clear-above
Clear all marks from articles with scores over the default score (or
over the numeric prefix) (@code{gnus-summary-clear-above}).

@item M V u
@kindex M V u (Summary)
@findex gnus-summary-tick-above
Tick all articles with scores over the default score (or over the
numeric prefix) (@code{gnus-summary-tick-above}).

@item M V m
@kindex M V m (Summary)
@findex gnus-summary-mark-above
Prompt for a mark, and mark all articles with scores over the default
score (or over the numeric prefix) with this mark
(@code{gnus-summary-clear-above}).
@end table

@vindex gnus-summary-goto-unread
The @code{gnus-summary-goto-unread} variable controls what action should
be taken after setting a mark.  If non-@code{nil}, point will move to
the next/previous unread article.  If @code{nil}, point will just move
one line up or down.  As a special case, if this variable is
@code{never}, all the marking commands as well as other commands (like
@kbd{SPACE}) will move to the next article, whether it is unread or not.
The default is @code{t}.


@node Setting Process Marks
@subsection Setting Process Marks
@cindex setting process marks

@table @kbd

@item M P p
@itemx #
@kindex # (Summary)
@kindex M P p (Summary)
@findex gnus-summary-mark-as-processable
Mark the current article with the process mark
(@code{gnus-summary-mark-as-processable}). 
@findex gnus-summary-unmark-as-processable

@item M P u 
@itemx M-#
@kindex M P u (Summary)
@kindex M-# (Summary)
Remove the process mark, if any, from the current article
(@code{gnus-summary-unmark-as-processable}).

@item M P U
@kindex M P U (Summary)
@findex gnus-summary-unmark-all-processable
Remove the process mark from all articles
(@code{gnus-summary-unmark-all-processable}). 

@item M P R
@kindex M P R (Summary)
@findex gnus-uu-mark-by-regexp
Mark articles by a regular expression (@code{gnus-uu-mark-by-regexp}). 

@item M P r
@kindex M P r (Summary)
@findex gnus-uu-mark-region
Mark articles in region (@code{gnus-uu-mark-region}).

@item M P t
@kindex M P t (Summary)
@findex gnus-uu-mark-thread
Mark all articles in the current (sub)thread
(@code{gnus-uu-mark-thread}).

@item M P T
@kindex M P T (Summary)
@findex gnus-uu-unmark-thread
Unmark all articles in the current (sub)thread
(@code{gnus-uu-unmark-thread}).

@item M P v
@kindex M P v (Summary)
@findex gnus-uu-mark-over
Mark all articles that have a score above the prefix argument
(@code{gnus-uu-mark-over}).

@item M P s
@kindex M P s (Summary)
@findex gnus-uu-mark-series
Mark all articles in the current series (@code{gnus-uu-mark-series}).

@item M P S
@kindex M P S (Summary)
@findex gnus-uu-mark-sparse
Mark all series that have already had some articles marked
(@code{gnus-uu-mark-sparse}).

@item M P a
@kindex M P a (Summary)
@findex gnus-uu-mark-all
Mark all articles in series order (@code{gnus-uu-mark-series}).

@item M P b
@kindex M P b (Summary)
@findex gnus-uu-mark-buffer
Mark all articles in the buffer in the order they appear
(@code{gnus-uu-mark-buffer}). 
@end table


@node Limiting
@section Limiting
@cindex limiting

It can be convenient to limit the summary buffer to just show some
subset of the articles currently in the group.  The effect most limit
commands have is to remove a few (or many) articles from the summary
buffer. 

@table @kbd

@item / /
@itemx / s
@kindex / / (Summary)
@findex gnus-summary-limit-to-subject
Limit the summary buffer to articles that match some subject
(@code{gnus-summary-limit-to-subject}). 

@item / a
@kindex / a (Summary)
@findex gnus-summary-limit-to-author
Limit the summary buffer to articles that match some author
(@code{gnus-summary-limit-to-author}).

@item / u
@itemx x
@kindex / u (Summary)
@kindex x (Summary)
@findex gnus-summary-limit-to-unread
Limit the summary buffer to articles that are not marked as read
(@code{gnus-summary-limit-to-unread}).  If given a prefix, limit the
buffer to articles that are strictly unread.  This means that ticked and
dormant articles will also be excluded.

@item / m
@kindex / m (Summary)
@findex gnus-summary-limit-to-marks
Ask for a mark and then limit to all articles that have not been marked
with that mark (@code{gnus-summary-limit-to-marks}).

@item / n
@kindex / n (Summary)
@findex gnus-summary-limit-to-articles
Limit the summary buffer to the current article
(@code{gnus-summary-limit-to-articles}).  Uses the process/prefix
convention (@pxref{Process/Prefix}).

@item / w
@kindex / w (Summary)
@findex gnus-summary-pop-limit
Pop the previous limit off the stack and restore it
(@code{gnus-summary-pop-limit}).  If given a prefix, pop all limits off
the stack.

@item / v
@kindex / v (Summary)
@findex gnus-summary-limit-to-score
Limit the summary buffer to articles that have a score at or above some
score (@code{gnus-summary-limit-to-score}).

@item / E
@itemx M S
@kindex M S (Summary)
@kindex / E (Summary)
@findex gnus-summary-limit-include-expunged
Display all expunged articles
(@code{gnus-summary-limit-include-expunged}). 

@item / D
@kindex / D (Summary)
@findex gnus-summary-limit-include-dormant
Display all dormant articles (@code{gnus-summary-limit-include-dormant}).

@item / d
@kindex / d (Summary)
@findex gnus-summary-limit-exclude-dormant
Hide all dormant articles (@code{gnus-summary-limit-exclude-dormant}).

@item / c
@kindex / c (Summary)
@findex gnus-summary-limit-exclude-childless-dormant
Hide all dormant articles that have no children
(@code{gnus-summary-limit-exclude-childless-dormant}). 

@item / C
@kindex / C (Summary)
@findex gnus-summary-limit-mark-excluded-as-read
Mark all excluded unread articles as read
(@code{gnus-summary-limit-mark-excluded-as-read}).   If given a prefix,
also mark excluded ticked and dormant articles as read.

@end table


@node Threading
@section Threading
@cindex threading
@cindex article threading

Gnus threads articles by default.  @dfn{To thread} is to put replies to
articles directly after the articles they reply to---in a hierarchical
fashion.

@menu
* Customizing Threading::     Variables you can change to affect the threading.
* Thread Commands::           Thread based commands in the summary buffer.
@end menu


@node Customizing Threading
@subsection Customizing Threading
@cindex customizing threading
@cindex <
@cindex >

@table @code

@item gnus-show-threads
@vindex gnus-show-threads
If this variable is @code{nil}, no threading will be done, and all of
the rest of the variables here will have no effect.  Turning threading
off will speed group selection up a bit, but it is sure to make reading
slower and more awkward.

@item gnus-fetch-old-headers
@vindex gnus-fetch-old-headers
If non-@code{nil}, Gnus will attempt to build old threads by fetching
more old headers---headers to articles that are marked as read.  If you
would like to display as few summary lines as possible, but still
connect as many loose threads as possible, you should set this variable
to @code{some} or a number.  If you set it to a number, no more than
that number of extra old headers will be fetched.  In either case,
fetching old headers only works if the backend you are using carries
overview files---this would normally be @code{nntp}, @code{nnspool} and
@code{nnml}.  Also remember that if the root of the thread has been
expired by the server, there's not much Gnus can do about that.

@item gnus-build-sparse-threads
@vindex gnus-build-sparse-threads
Fetching old headers can be slow.  A low-rent similar effect can be
gotten by setting this variable to @code{some}.  Gnus will then look at
the complete @code{References} headers of all articles and try to string
articles that belong in the same thread together.  This will leave
@dfn{gaps} in the threading display where Gnus guesses that an article
is missing from the thread.  (These gaps appear like normal summary
lines.  If you select a gap, Gnus will try to fetch the article in
question.)  If this variable is @code{t}, Gnus will display all these
``gaps'' without regard for whether they are useful for completing the
thread or not.  Finally, if this variable is @code{more}, Gnus won't cut
off sparse leaf nodes that don't lead anywhere.  This variable is
@code{nil} by default.

@item gnus-summary-gather-subject-limit
@vindex gnus-summary-gather-subject-limit
Loose threads are gathered by comparing subjects of articles.  If this
variable is @code{nil}, Gnus requires an exact match between the
subjects of the loose threads before gathering them into one big
super-thread.  This might be too strict a requirement, what with the
presence of stupid newsreaders that chop off long subjects lines.  If
you think so, set this variable to, say, 20 to require that only the
first 20 characters of the subjects have to match.  If you set this
variable to a really low number, you'll find that Gnus will gather
everything in sight into one thread, which isn't very helpful.

@cindex fuzzy article gathering
If you set this variable to the special value @code{fuzzy}, Gnus will
use a fuzzy string comparison algorithm on the subjects.

@item gnus-simplify-subject-fuzzy-regexp
@vindex gnus-simplify-subject-fuzzy-regexp
This can either be a regular expression or list of regular expressions
that match strings that will be removed from subjects if fuzzy subject
simplification is used.

@item gnus-simplify-ignored-prefixes
@vindex gnus-simplify-ignored-prefixes
If you set @code{gnus-summary-gather-subject-limit} to something as low
as 10, you might consider setting this variable to something sensible:

@c Written by Michael Ernst <mernst@cs.rice.edu>
@lisp
(setq gnus-simplify-ignored-prefixes
      (concat 
       "\\`\\[?\\("
       (mapconcat 'identity
                  '("looking"
                     "wanted" "followup" "summary\\( of\\)?"
                     "help" "query" "problem" "question" 
                     "answer" "reference" "announce"
                     "How can I" "How to" "Comparison of"
                     ;; ...
                     )
                  "\\|")
                  "\\)\\s *\\("
                  (mapconcat 'identity
                             '("for" "for reference" "with" "about")
                             "\\|")
                  "\\)?\\]?:?[ \t]*"))
@end lisp

All words that match this regexp will be removed before comparing two
subjects. 

@item gnus-summary-gather-exclude-subject
@vindex gnus-summary-gather-exclude-subject
Since loose thread gathering is done on subjects only, that might lead
to many false hits, especially with certain common subjects like
@samp{} and @samp{(none)}.  To make the situation slightly better,
you can use the regexp @code{gnus-summary-gather-exclude-subject} to say
what subjects should be excluded from the gathering process.  The
default is @samp{^ *$\\|^(none)$}.  

@item gnus-summary-thread-gathering-function
@vindex gnus-summary-thread-gathering-function
Gnus gathers threads by looking at @code{Subject} headers.  This means
that totally unrelated articles may end up in the same ``thread'', which
is confusing.  An alternate approach is to look at all the
@code{Message-ID}s in all the @code{References} headers to find matches.
This will ensure that no gathered threads ever includes unrelated
articles, but it's also means that people who have posted with broken
newsreaders won't be gathered properly.  The choice is yours---plague or
cholera:

@table @code
@item gnus-gather-threads-by-subject
@findex gnus-gather-threads-by-subject
This function is the default gathering function and looks at
@code{Subject}s exclusively.

@item gnus-gather-threads-by-references
@findex gnus-gather-threads-by-references
This function looks at @code{References} headers exclusively.
@end table

If you want to test gathering by @code{References}, you could say
something like:

@lisp
(setq gnus-summary-thread-gathering-function
      'gnus-gather-threads-by-references)
@end lisp

@item gnus-summary-make-false-root
@vindex gnus-summary-make-false-root
If non-@code{nil}, Gnus will gather all loose subtrees into one big tree
and create a dummy root at the top.  (Wait a minute.  Root at the top?
Yup.)  Loose subtrees occur when the real root has expired, or you've
read or killed the root in a previous session.

When there is no real root of a thread, Gnus will have to fudge
something.  This variable says what fudging method Gnus should use.
There are four possible values:

@cindex adopting articles

@table @code

@item adopt
Gnus will make the first of the orphaned articles the parent.  This
parent will adopt all the other articles.  The adopted articles will be
marked as such by pointy brackets (@samp{<>}) instead of the standard
square brackets (@samp{[]}).  This is the default method.

@item dummy
@vindex gnus-summary-dummy-line-format
Gnus will create a dummy summary line that will pretend to be the
parent.  This dummy line does not correspond to any real article, so
selecting it will just select the first real article after the dummy
article.  @code{gnus-summary-dummy-line-format} is used to specify the
format of the dummy roots.  It accepts only one format spec:  @samp{S},
which is the subject of the article.  @xref{Formatting Variables}.

@item empty
Gnus won't actually make any article the parent, but simply leave the
subject field of all orphans except the first empty.  (Actually, it will
use @code{gnus-summary-same-subject} as the subject (@pxref{Summary
Buffer Format}).)

@item none
Don't make any article parent at all.  Just gather the threads and
display them after one another.

@item nil
Don't gather loose threads.
@end table

@item gnus-thread-hide-subtree
@vindex gnus-thread-hide-subtree
If non-@code{nil}, all threads will be hidden when the summary buffer is
generated.

@item gnus-thread-hide-killed
@vindex gnus-thread-hide-killed
if you kill a thread and this variable is non-@code{nil}, the subtree
will be hidden.

@item gnus-thread-ignore-subject
@vindex gnus-thread-ignore-subject
Sometimes somebody changes the subject in the middle of a thread.  If
this variable is non-@code{nil}, the subject change is ignored.  If it
is @code{nil}, which is the default, a change in the subject will result
in a new thread.

@item gnus-thread-indent-level
@vindex gnus-thread-indent-level
This is a number that says how much each sub-thread should be indented.
The default is @code{4}.
@end table


@node Thread Commands
@subsection Thread Commands
@cindex thread commands

@table @kbd

@item T k
@itemx M-C-k
@kindex T k (Summary)
@kindex M-C-k (Summary)
@findex gnus-summary-kill-thread
Mark all articles in the current sub-thread as read
(@code{gnus-summary-kill-thread}).  If the prefix argument is positive,
remove all marks instead.  If the prefix argument is negative, tick
articles instead.

@item T l
@itemx M-C-l
@kindex T l (Summary)
@kindex M-C-l (Summary)
@findex gnus-summary-lower-thread
Lower the score of the current thread
(@code{gnus-summary-lower-thread}).