+@item
+The first element is the @dfn{match element}. On most headers this will
+be a string, but on the Lines and Chars headers, this must be an
+integer.
+
+@item
+If the second element is present, it should be a number---the @dfn{score
+element}. This number should be an integer in the neginf to posinf
+interval. This number is added to the score of the article if the match
+is successful. If this element is not present, the
+@code{gnus-score-interactive-default-score} number will be used
+instead. This is 1000 by default.
+
+@item
+If the third element is present, it should be a number---the @dfn{date
+element}. This date says when the last time this score entry matched,
+which provides a mechanism for expiring the score entries. It this
+element is not present, the score entry is permanent. The date is
+represented by the number of days since December 31, 1 BCE.
+
+@item
+If the fourth element is present, it should be a symbol---the @dfn{type
+element}. This element specifies what function should be used to see
+whether this score entry matches the article. What match types that can
+be used depends on what header you wish to perform the match on.
+@table @dfn
+
+@item From, Subject, References, Xref, Message-ID
+For most header types, there are the @code{r} and @code{R} (regexp), as
+well as @code{s} and @code{S} (substring) types, and @code{e} and
+@code{E} (exact match), and @code{w} (word match) types. If this
+element is not present, Gnus will assume that substring matching should
+be used. @code{R}, @code{S}, and @code{E} differ from the others in
+that the matches will be done in a case-sensitive manner. All these
+one-letter types are really just abbreviations for the @code{regexp},
+@code{string}, @code{exact}, and @code{word} types, which you can use
+instead, if you feel like.
+
+@item Extra
+Just as for the standard string overview headers, if you are using
+gnus-extra-headers, you can score on these headers' values. In this
+case, there is a 5th element in the score entry, being the name of the
+header to be scored. The following entry is useful in your
+@file{all.SCORE} file in case of spam attacks from a single origin
+host, if your @acronym{NNTP} server tracks @samp{NNTP-Posting-Host} in
+overviews:
+
+@lisp
+("111.222.333.444" -1000 nil s
+ "NNTP-Posting-Host")
+@end lisp
+
+@item Lines, Chars
+These two headers use different match types: @code{<}, @code{>},
+@code{=}, @code{>=} and @code{<=}.
+
+These predicates are true if
+
+@example
+(PREDICATE HEADER MATCH)
+@end example
+
+evaluates to non-@code{nil}. For instance, the advanced match
+@code{("lines" 4 <)} (@pxref{Advanced Scoring}) will result in the
+following form:
+
+@lisp
+(< header-value 4)
+@end lisp
+
+Or to put it another way: When using @code{<} on @code{Lines} with 4 as
+the match, we get the score added if the article has less than 4 lines.
+(It's easy to get confused and think it's the other way around. But
+it's not. I think.)
+
+When matching on @code{Lines}, be careful because some back ends (like
+@code{nndir}) do not generate @code{Lines} header, so every article ends
+up being marked as having 0 lines. This can lead to strange results if
+you happen to lower score of the articles with few lines.
+
+@item Date
+For the Date header we have three kinda silly match types:
+@code{before}, @code{at} and @code{after}. I can't really imagine this
+ever being useful, but, like, it would feel kinda silly not to provide
+this function. Just in case. You never know. Better safe than sorry.
+Once burnt, twice shy. Don't judge a book by its cover. Never not have
+sex on a first date. (I have been told that at least one person, and I
+quote, ``found this function indispensable'', however.)
+
+@cindex ISO8601
+@cindex date
+A more useful match type is @code{regexp}. With it, you can match the
+date string using a regular expression. The date is normalized to
+ISO8601 compact format first---@var{YYYYMMDD}@code{T}@var{HHMMSS}. If
+you want to match all articles that have been posted on April 1st in
+every year, you could use @samp{....0401.........} as a match string,
+for instance. (Note that the date is kept in its original time zone, so
+this will match articles that were posted when it was April 1st where
+the article was posted from. Time zones are such wholesome fun for the
+whole family, eh?)
+
+@item Head, Body, All
+These three match keys use the same match types as the @code{From} (etc)
+header uses.
+
+@item Followup
+This match key is somewhat special, in that it will match the
+@code{From} header, and affect the score of not only the matching
+articles, but also all followups to the matching articles. This allows
+you e.g. increase the score of followups to your own articles, or
+decrease the score of followups to the articles of some known
+trouble-maker. Uses the same match types as the @code{From} header
+uses. (Using this match key will lead to creation of @file{ADAPT}
+files.)
+
+@item Thread
+This match key works along the same lines as the @code{Followup} match
+key. If you say that you want to score on a (sub-)thread started by an
+article with a @code{Message-ID} @var{x}, then you add a @samp{thread}
+match. This will add a new @samp{thread} match for each article that
+has @var{x} in its @code{References} header. (These new @samp{thread}
+matches will use the @code{Message-ID}s of these matching articles.)
+This will ensure that you can raise/lower the score of an entire thread,
+even though some articles in the thread may not have complete
+@code{References} headers. Note that using this may lead to
+undeterministic scores of the articles in the thread. (Using this match
+key will lead to creation of @file{ADAPT} files.)
+@end table
+@end enumerate
+
+@cindex score file atoms
+@item mark
+The value of this entry should be a number. Any articles with a score
+lower than this number will be marked as read.
+
+@item expunge
+The value of this entry should be a number. Any articles with a score
+lower than this number will be removed from the summary buffer.
+
+@item mark-and-expunge
+The value of this entry should be a number. Any articles with a score
+lower than this number will be marked as read and removed from the
+summary buffer.
+
+@item thread-mark-and-expunge
+The value of this entry should be a number. All articles that belong to
+a thread that has a total score below this number will be marked as read
+and removed from the summary buffer. @code{gnus-thread-score-function}
+says how to compute the total score for a thread.
+
+@item files
+The value of this entry should be any number of file names. These files
+are assumed to be score files as well, and will be loaded the same way
+this one was.
+
+@item exclude-files
+The clue of this entry should be any number of files. These files will
+not be loaded, even though they would normally be so, for some reason or
+other.
+
+@item eval
+The value of this entry will be @code{eval}el. This element will be
+ignored when handling global score files.
+
+@item read-only
+Read-only score files will not be updated or saved. Global score files
+should feature this atom (@pxref{Global Score Files}). (Note:
+@dfn{Global} here really means @dfn{global}; not your personal
+apply-to-all-groups score files.)
+
+@item orphan
+The value of this entry should be a number. Articles that do not have
+parents will get this number added to their scores. Imagine you follow
+some high-volume newsgroup, like @samp{comp.lang.c}. Most likely you
+will only follow a few of the threads, also want to see any new threads.
+
+You can do this with the following two score file entries:
+
+@example
+ (orphan -500)
+ (mark-and-expunge -100)
+@end example
+
+When you enter the group the first time, you will only see the new
+threads. You then raise the score of the threads that you find
+interesting (with @kbd{I T} or @kbd{I S}), and ignore (@kbd{C y}) the
+rest. Next time you enter the group, you will see new articles in the
+interesting threads, plus any new threads.
+
+I.e.---the orphan score atom is for high-volume groups where a few
+interesting threads which can't be found automatically by ordinary
+scoring rules exist.
+
+@item adapt
+This entry controls the adaptive scoring. If it is @code{t}, the
+default adaptive scoring rules will be used. If it is @code{ignore}, no
+adaptive scoring will be performed on this group. If it is a list, this
+list will be used as the adaptive scoring rules. If it isn't present,
+or is something other than @code{t} or @code{ignore}, the default
+adaptive scoring rules will be used. If you want to use adaptive
+scoring on most groups, you'd set @code{gnus-use-adaptive-scoring} to
+@code{t}, and insert an @code{(adapt ignore)} in the groups where you do
+not want adaptive scoring. If you only want adaptive scoring in a few
+groups, you'd set @code{gnus-use-adaptive-scoring} to @code{nil}, and
+insert @code{(adapt t)} in the score files of the groups where you want
+it.
+
+@item adapt-file
+All adaptive score entries will go to the file named by this entry. It
+will also be applied when entering the group. This atom might be handy
+if you want to adapt on several groups at once, using the same adaptive
+file for a number of groups.
+
+@item local
+@cindex local variables
+The value of this entry should be a list of @code{(@var{var}
+@var{value})} pairs. Each @var{var} will be made buffer-local to the
+current summary buffer, and set to the value specified. This is a
+convenient, if somewhat strange, way of setting variables in some
+groups if you don't like hooks much. Note that the @var{value} won't
+be evaluated.
+@end table
+
+
+@node Score File Editing
+@section Score File Editing
+
+You normally enter all scoring commands from the summary buffer, but you
+might feel the urge to edit them by hand as well, so we've supplied you
+with a mode for that.
+
+It's simply a slightly customized @code{emacs-lisp} mode, with these
+additional commands:
+
+@table @kbd
+
+@item C-c C-c
+@kindex C-c C-c (Score)
+@findex gnus-score-edit-done
+Save the changes you have made and return to the summary buffer
+(@code{gnus-score-edit-done}).
+
+@item C-c C-d
+@kindex C-c C-d (Score)
+@findex gnus-score-edit-insert-date
+Insert the current date in numerical format
+(@code{gnus-score-edit-insert-date}). This is really the day number, if
+you were wondering.
+
+@item C-c C-p
+@kindex C-c C-p (Score)
+@findex gnus-score-pretty-print
+The adaptive score files are saved in an unformatted fashion. If you
+intend to read one of these files, you want to @dfn{pretty print} it
+first. This command (@code{gnus-score-pretty-print}) does that for
+you.
+
+@end table
+
+Type @kbd{M-x gnus-score-mode} to use this mode.
+
+@vindex gnus-score-mode-hook
+@code{gnus-score-menu-hook} is run in score mode buffers.
+
+In the summary buffer you can use commands like @kbd{V f}, @kbd{V e} and
+@kbd{V t} to begin editing score files.
+
+
+@node Adaptive Scoring
+@section Adaptive Scoring
+@cindex adaptive scoring
+
+If all this scoring is getting you down, Gnus has a way of making it all
+happen automatically---as if by magic. Or rather, as if by artificial
+stupidity, to be precise.
+
+@vindex gnus-use-adaptive-scoring
+When you read an article, or mark an article as read, or kill an
+article, you leave marks behind. On exit from the group, Gnus can sniff
+these marks and add score elements depending on what marks it finds.
+You turn on this ability by setting @code{gnus-use-adaptive-scoring} to
+@code{t} or @code{(line)}. If you want score adaptively on separate
+words appearing in the subjects, you should set this variable to
+@code{(word)}. If you want to use both adaptive methods, set this
+variable to @code{(word line)}.
+
+@vindex gnus-default-adaptive-score-alist
+To give you complete control over the scoring process, you can customize
+the @code{gnus-default-adaptive-score-alist} variable. For instance, it
+might look something like this:
+
+@lisp
+(setq gnus-default-adaptive-score-alist
+ '((gnus-unread-mark)
+ (gnus-ticked-mark (from 4))
+ (gnus-dormant-mark (from 5))
+ (gnus-del-mark (from -4) (subject -1))
+ (gnus-read-mark (from 4) (subject 2))
+ (gnus-expirable-mark (from -1) (subject -1))
+ (gnus-killed-mark (from -1) (subject -3))
+ (gnus-kill-file-mark)
+ (gnus-ancient-mark)
+ (gnus-low-score-mark)
+ (gnus-catchup-mark (from -1) (subject -1))))
+@end lisp
+
+As you see, each element in this alist has a mark as a key (either a
+variable name or a ``real'' mark---a character). Following this key is
+a arbitrary number of header/score pairs. If there are no header/score
+pairs following the key, no adaptive scoring will be done on articles
+that have that key as the article mark. For instance, articles with
+@code{gnus-unread-mark} in the example above will not get adaptive score
+entries.
+
+Each article can have only one mark, so just a single of these rules
+will be applied to each article.
+
+To take @code{gnus-del-mark} as an example---this alist says that all
+articles that have that mark (i.e., are marked with @samp{e}) will have a
+score entry added to lower based on the @code{From} header by -4, and
+lowered by @code{Subject} by -1. Change this to fit your prejudices.
+
+If you have marked 10 articles with the same subject with
+@code{gnus-del-mark}, the rule for that mark will be applied ten times.
+That means that that subject will get a score of ten times -1, which
+should be, unless I'm much mistaken, -10.
+
+If you have auto-expirable (mail) groups (@pxref{Expiring Mail}), all
+the read articles will be marked with the @samp{E} mark. This'll
+probably make adaptive scoring slightly impossible, so auto-expiring and
+adaptive scoring doesn't really mix very well.
+
+The headers you can score on are @code{from}, @code{subject},
+@code{message-id}, @code{references}, @code{xref}, @code{lines},
+@code{chars} and @code{date}. In addition, you can score on
+@code{followup}, which will create an adaptive score entry that matches
+on the @code{References} header using the @code{Message-ID} of the
+current article, thereby matching the following thread.
+
+If you use this scheme, you should set the score file atom @code{mark}
+to something small---like -300, perhaps, to avoid having small random
+changes result in articles getting marked as read.
+
+After using adaptive scoring for a week or so, Gnus should start to
+become properly trained and enhance the authors you like best, and kill
+the authors you like least, without you having to say so explicitly.
+
+You can control what groups the adaptive scoring is to be performed on
+by using the score files (@pxref{Score File Format}). This will also
+let you use different rules in different groups.
+
+@vindex gnus-adaptive-file-suffix
+The adaptive score entries will be put into a file where the name is the
+group name with @code{gnus-adaptive-file-suffix} appended. The default
+is @file{ADAPT}.
+
+@vindex gnus-score-exact-adapt-limit
+When doing adaptive scoring, substring or fuzzy matching would probably
+give you the best results in most cases. However, if the header one
+matches is short, the possibility for false positives is great, so if
+the length of the match is less than
+@code{gnus-score-exact-adapt-limit}, exact matching will be used. If
+this variable is @code{nil}, exact matching will always be used to avoid
+this problem.
+
+@vindex gnus-default-adaptive-word-score-alist
+As mentioned above, you can adapt either on individual words or entire
+headers. If you adapt on words, the
+@code{gnus-default-adaptive-word-score-alist} variable says what score
+each instance of a word should add given a mark.
+
+@lisp
+(setq gnus-default-adaptive-word-score-alist
+ `((,gnus-read-mark . 30)
+ (,gnus-catchup-mark . -10)
+ (,gnus-killed-mark . -20)
+ (,gnus-del-mark . -15)))
+@end lisp
+
+This is the default value. If you have adaption on words enabled, every
+word that appears in subjects of articles marked with
+@code{gnus-read-mark} will result in a score rule that increase the
+score with 30 points.
+
+@vindex gnus-default-ignored-adaptive-words
+@vindex gnus-ignored-adaptive-words
+Words that appear in the @code{gnus-default-ignored-adaptive-words} list
+will be ignored. If you wish to add more words to be ignored, use the
+@code{gnus-ignored-adaptive-words} list instead.
+
+@vindex gnus-adaptive-word-length-limit
+Some may feel that short words shouldn't count when doing adaptive
+scoring. If so, you may set @code{gnus-adaptive-word-length-limit} to
+an integer. Words shorter than this number will be ignored. This
+variable defaults to @code{nil}.
+
+@vindex gnus-adaptive-word-syntax-table
+When the scoring is done, @code{gnus-adaptive-word-syntax-table} is the
+syntax table in effect. It is similar to the standard syntax table, but
+it considers numbers to be non-word-constituent characters.
+
+@vindex gnus-adaptive-word-minimum
+If @code{gnus-adaptive-word-minimum} is set to a number, the adaptive
+word scoring process will never bring down the score of an article to
+below this number. The default is @code{nil}.
+
+@vindex gnus-adaptive-word-no-group-words
+If @code{gnus-adaptive-word-no-group-words} is set to @code{t}, gnus
+won't adaptively word score any of the words in the group name. Useful
+for groups like @samp{comp.editors.emacs}, where most of the subject
+lines contain the word @samp{emacs}.
+
+After using this scheme for a while, it might be nice to write a
+@code{gnus-psychoanalyze-user} command to go through the rules and see
+what words you like and what words you don't like. Or perhaps not.
+
+Note that the adaptive word scoring thing is highly experimental and is
+likely to change in the future. Initial impressions seem to indicate
+that it's totally useless as it stands. Some more work (involving more
+rigorous statistical methods) will have to be done to make this useful.
+
+
+@node Home Score File
+@section Home Score File
+
+The score file where new score file entries will go is called the
+@dfn{home score file}. This is normally (and by default) the score file
+for the group itself. For instance, the home score file for
+@samp{gnu.emacs.gnus} is @file{gnu.emacs.gnus.SCORE}.
+
+However, this may not be what you want. It is often convenient to share
+a common home score file among many groups---all @samp{emacs} groups
+could perhaps use the same home score file.
+
+@vindex gnus-home-score-file
+The variable that controls this is @code{gnus-home-score-file}. It can
+be:
+
+@enumerate
+@item
+A string. Then this file will be used as the home score file for all
+groups.
+
+@item
+A function. The result of this function will be used as the home score
+file. The function will be called with the name of the group as the
+parameter.
+
+@item
+A list. The elements in this list can be:
+
+@enumerate
+@item
+@code{(@var{regexp} @var{file-name})}. If the @var{regexp} matches the
+group name, the @var{file-name} will be used as the home score file.
+
+@item
+A function. If the function returns non-@code{nil}, the result will
+be used as the home score file.
+
+@item
+A string. Use the string as the home score file.
+@end enumerate
+
+The list will be traversed from the beginning towards the end looking
+for matches.
+
+@end enumerate
+
+So, if you want to use just a single score file, you could say:
+
+@lisp
+(setq gnus-home-score-file
+ "my-total-score-file.SCORE")
+@end lisp
+
+If you want to use @file{gnu.SCORE} for all @samp{gnu} groups and
+@file{rec.SCORE} for all @samp{rec} groups (and so on), you can say:
+
+@findex gnus-hierarchial-home-score-file
+@lisp
+(setq gnus-home-score-file
+ 'gnus-hierarchial-home-score-file)
+@end lisp
+
+This is a ready-made function provided for your convenience.
+Other functions include
+
+@table @code
+@item gnus-current-home-score-file
+@findex gnus-current-home-score-file
+Return the ``current'' regular score file. This will make scoring
+commands add entry to the ``innermost'' matching score file.
+
+@end table
+
+If you want to have one score file for the @samp{emacs} groups and
+another for the @samp{comp} groups, while letting all other groups use
+their own home score files:
+
+@lisp
+(setq gnus-home-score-file
+ ;; @r{All groups that match the regexp @code{"\\.emacs"}}
+ '(("\\.emacs" "emacs.SCORE")
+ ;; @r{All the comp groups in one score file}
+ ("^comp" "comp.SCORE")))
+@end lisp
+
+@vindex gnus-home-adapt-file
+@code{gnus-home-adapt-file} works exactly the same way as
+@code{gnus-home-score-file}, but says what the home adaptive score file
+is instead. All new adaptive file entries will go into the file
+specified by this variable, and the same syntax is allowed.
+
+In addition to using @code{gnus-home-score-file} and
+@code{gnus-home-adapt-file}, you can also use group parameters
+(@pxref{Group Parameters}) and topic parameters (@pxref{Topic
+Parameters}) to achieve much the same. Group and topic parameters take
+precedence over this variable.
+
+
+@node Followups To Yourself
+@section Followups To Yourself
+
+Gnus offers two commands for picking out the @code{Message-ID} header in
+the current buffer. Gnus will then add a score rule that scores using
+this @code{Message-ID} on the @code{References} header of other
+articles. This will, in effect, increase the score of all articles that
+respond to the article in the current buffer. Quite useful if you want
+to easily note when people answer what you've said.
+
+@table @code
+
+@item gnus-score-followup-article
+@findex gnus-score-followup-article
+This will add a score to articles that directly follow up your own
+article.
+
+@item gnus-score-followup-thread
+@findex gnus-score-followup-thread
+This will add a score to all articles that appear in a thread ``below''
+your own article.
+@end table
+
+@vindex message-sent-hook
+These two functions are both primarily meant to be used in hooks like
+@code{message-sent-hook}, like this:
+@lisp
+(add-hook 'message-sent-hook 'gnus-score-followup-thread)
+@end lisp
+
+
+If you look closely at your own @code{Message-ID}, you'll notice that
+the first two or three characters are always the same. Here's two of
+mine:
+
+@example
+<x6u3u47icf.fsf@@eyesore.no>
+<x6sp9o7ibw.fsf@@eyesore.no>
+@end example
+
+So ``my'' ident on this machine is @samp{x6}. This can be
+exploited---the following rule will raise the score on all followups to
+myself:
+
+@lisp
+("references"
+ ("<x6[0-9a-z]+\\.fsf\\(_-_\\)?@@.*eyesore\\.no>"
+ 1000 nil r))
+@end lisp
+
+Whether it's the first two or first three characters that are ``yours''
+is system-dependent.
+
+
+@node Scoring On Other Headers
+@section Scoring On Other Headers
+@cindex scoring on other headers
+
+Gnus is quite fast when scoring the ``traditional''
+headers---@samp{From}, @samp{Subject} and so on. However, scoring
+other headers requires writing a @code{head} scoring rule, which means
+that Gnus has to request every single article from the back end to find
+matches. This takes a long time in big groups.
+
+Now, there's not much you can do about this for news groups, but for
+mail groups, you have greater control. In @ref{To From Newsgroups},
+it's explained in greater detail what this mechanism does, but here's
+a cookbook example for @code{nnml} on how to allow scoring on the
+@samp{To} and @samp{Cc} headers.
+
+Put the following in your @file{~/.gnus.el} file.
+
+@lisp
+(setq gnus-extra-headers '(To Cc Newsgroups Keywords)
+ nnmail-extra-headers gnus-extra-headers)
+@end lisp
+
+Restart Gnus and rebuild your @code{nnml} overview files with the
+@kbd{M-x nnml-generate-nov-databases} command. This will take a long
+time if you have much mail.
+
+Now you can score on @samp{To} and @samp{Cc} as ``extra headers'' like
+so: @kbd{I e s p To RET <your name> RET}.
+
+See? Simple.
+
+
+@node Scoring Tips
+@section Scoring Tips
+@cindex scoring tips
+
+@table @dfn
+
+@item Crossposts
+@cindex crossposts
+@cindex scoring crossposts
+If you want to lower the score of crossposts, the line to match on is
+the @code{Xref} header.
+@lisp
+("xref" (" talk.politics.misc:" -1000))
+@end lisp
+
+@item Multiple crossposts
+If you want to lower the score of articles that have been crossposted to
+more than, say, 3 groups:
+@lisp
+("xref"
+ ("[^:\n]+:[0-9]+ +[^:\n]+:[0-9]+ +[^:\n]+:[0-9]+"
+ -1000 nil r))
+@end lisp
+
+@item Matching on the body
+This is generally not a very good idea---it takes a very long time.
+Gnus actually has to fetch each individual article from the server. But
+you might want to anyway, I guess. Even though there are three match
+keys (@code{Head}, @code{Body} and @code{All}), you should choose one
+and stick with it in each score file. If you use any two, each article
+will be fetched @emph{twice}. If you want to match a bit on the
+@code{Head} and a bit on the @code{Body}, just use @code{All} for all
+the matches.
+
+@item Marking as read
+You will probably want to mark articles that have scores below a certain
+number as read. This is most easily achieved by putting the following
+in your @file{all.SCORE} file:
+@lisp
+((mark -100))
+@end lisp
+You may also consider doing something similar with @code{expunge}.
+
+@item Negated character classes
+If you say stuff like @code{[^abcd]*}, you may get unexpected results.
+That will match newlines, which might lead to, well, The Unknown. Say
+@code{[^abcd\n]*} instead.
+@end table
+
+
+@node Reverse Scoring
+@section Reverse Scoring
+@cindex reverse scoring
+
+If you want to keep just articles that have @samp{Sex with Emacs} in the
+subject header, and expunge all other articles, you could put something
+like this in your score file:
+
+@lisp
+(("subject"
+ ("Sex with Emacs" 2))
+ (mark 1)
+ (expunge 1))
+@end lisp
+
+So, you raise all articles that match @samp{Sex with Emacs} and mark the
+rest as read, and expunge them to boot.
+
+
+@node Global Score Files
+@section Global Score Files
+@cindex global score files
+
+Sure, other newsreaders have ``global kill files''. These are usually
+nothing more than a single kill file that applies to all groups, stored
+in the user's home directory. Bah! Puny, weak newsreaders!
+
+What I'm talking about here are Global Score Files. Score files from
+all over the world, from users everywhere, uniting all nations in one
+big, happy score file union! Ange-score! New and untested!
+
+@vindex gnus-global-score-files
+All you have to do to use other people's score files is to set the
+@code{gnus-global-score-files} variable. One entry for each score file,
+or each score file directory. Gnus will decide by itself what score
+files are applicable to which group.
+
+To use the score file
+@file{/ftp@@ftp.gnus.org:/pub/larsi/ding/score/soc.motss.SCORE} and
+all score files in the @file{/ftp@@ftp.some-where:/pub/score} directory,
+say this:
+
+@lisp
+(setq gnus-global-score-files
+ '("/ftp@@ftp.gnus.org:/pub/larsi/ding/score/soc.motss.SCORE"
+ "/ftp@@ftp.some-where:/pub/score/"))
+@end lisp
+
+@findex gnus-score-search-global-directories
+@noindent
+Simple, eh? Directory names must end with a @samp{/}. These
+directories are typically scanned only once during each Gnus session.
+If you feel the need to manually re-scan the remote directories, you can
+use the @code{gnus-score-search-global-directories} command.
+
+Note that, at present, using this option will slow down group entry
+somewhat. (That is---a lot.)
+
+If you want to start maintaining score files for other people to use,
+just put your score file up for anonymous ftp and announce it to the
+world. Become a retro-moderator! Participate in the retro-moderator
+wars sure to ensue, where retro-moderators battle it out for the
+sympathy of the people, luring them to use their score files on false
+premises! Yay! The net is saved!
+
+Here are some tips for the would-be retro-moderator, off the top of my
+head:
+
+@itemize @bullet
+
+@item
+Articles heavily crossposted are probably junk.
+@item
+To lower a single inappropriate article, lower by @code{Message-ID}.
+@item
+Particularly brilliant authors can be raised on a permanent basis.
+@item
+Authors that repeatedly post off-charter for the group can safely be
+lowered out of existence.
+@item
+Set the @code{mark} and @code{expunge} atoms to obliterate the nastiest
+articles completely.
+
+@item
+Use expiring score entries to keep the size of the file down. You
+should probably have a long expiry period, though, as some sites keep
+old articles for a long time.
+@end itemize
+
+@dots{} I wonder whether other newsreaders will support global score files
+in the future. @emph{Snicker}. Yup, any day now, newsreaders like Blue
+Wave, xrn and 1stReader are bound to implement scoring. Should we start
+holding our breath yet?
+
+
+@node Kill Files
+@section Kill Files
+@cindex kill files
+
+Gnus still supports those pesky old kill files. In fact, the kill file
+entries can now be expiring, which is something I wrote before Daniel
+Quinlan thought of doing score files, so I've left the code in there.
+
+In short, kill processing is a lot slower (and I do mean @emph{a lot})
+than score processing, so it might be a good idea to rewrite your kill
+files into score files.
+
+Anyway, a kill file is a normal @code{emacs-lisp} file. You can put any
+forms into this file, which means that you can use kill files as some
+sort of primitive hook function to be run on group entry, even though
+that isn't a very good idea.
+
+Normal kill files look like this:
+
+@lisp
+(gnus-kill "From" "Lars Ingebrigtsen")
+(gnus-kill "Subject" "ding")
+(gnus-expunge "X")
+@end lisp
+
+This will mark every article written by me as read, and remove the
+marked articles from the summary buffer. Very useful, you'll agree.
+
+Other programs use a totally different kill file syntax. If Gnus
+encounters what looks like a @code{rn} kill file, it will take a stab at
+interpreting it.
+
+Two summary functions for editing a @sc{gnus} kill file:
+
+@table @kbd
+
+@item M-k
+@kindex M-k (Summary)
+@findex gnus-summary-edit-local-kill
+Edit this group's kill file (@code{gnus-summary-edit-local-kill}).
+
+@item M-K
+@kindex M-K (Summary)
+@findex gnus-summary-edit-global-kill
+Edit the general kill file (@code{gnus-summary-edit-global-kill}).
+@end table
+
+Two group mode functions for editing the kill files:
+
+@table @kbd
+
+@item M-k
+@kindex M-k (Group)
+@findex gnus-group-edit-local-kill
+Edit this group's kill file (@code{gnus-group-edit-local-kill}).
+
+@item M-K
+@kindex M-K (Group)
+@findex gnus-group-edit-global-kill
+Edit the general kill file (@code{gnus-group-edit-global-kill}).
+@end table
+
+Kill file variables:
+
+@table @code
+@item gnus-kill-file-name
+@vindex gnus-kill-file-name
+A kill file for the group @samp{soc.motss} is normally called
+@file{soc.motss.KILL}. The suffix appended to the group name to get
+this file name is detailed by the @code{gnus-kill-file-name} variable.
+The ``global'' kill file (not in the score file sense of ``global'', of
+course) is just called @file{KILL}.
+
+@vindex gnus-kill-save-kill-file
+@item gnus-kill-save-kill-file
+If this variable is non-@code{nil}, Gnus will save the
+kill file after processing, which is necessary if you use expiring
+kills.
+
+@item gnus-apply-kill-hook
+@vindex gnus-apply-kill-hook
+@findex gnus-apply-kill-file-unless-scored
+@findex gnus-apply-kill-file
+A hook called to apply kill files to a group. It is
+@code{(gnus-apply-kill-file)} by default. If you want to ignore the
+kill file if you have a score file for the same group, you can set this
+hook to @code{(gnus-apply-kill-file-unless-scored)}. If you don't want
+kill files to be processed, you should set this variable to @code{nil}.
+
+@item gnus-kill-file-mode-hook
+@vindex gnus-kill-file-mode-hook
+A hook called in kill-file mode buffers.
+
+@end table
+
+
+@node Converting Kill Files
+@section Converting Kill Files
+@cindex kill files
+@cindex converting kill files
+
+If you have loads of old kill files, you may want to convert them into
+score files. If they are ``regular'', you can use
+the @file{gnus-kill-to-score.el} package; if not, you'll have to do it
+by hand.
+
+The kill to score conversion package isn't included in Gnus by default.
+You can fetch it from
+@uref{http://www.stud.ifi.uio.no/~larsi/ding-various/gnus-kill-to-score.el}.
+
+If your old kill files are very complex---if they contain more
+non-@code{gnus-kill} forms than not, you'll have to convert them by
+hand. Or just let them be as they are. Gnus will still use them as
+before.
+
+
+@node GroupLens
+@section GroupLens
+@cindex GroupLens
+
+@sc{Note:} Unfortunately the GroupLens system seems to have shut down,
+so this section is mostly of historical interest.
+
+@uref{http://www.cs.umn.edu/Research/GroupLens/, GroupLens} is a
+collaborative filtering system that helps you work together with other
+people to find the quality news articles out of the huge volume of
+news articles generated every day.
+
+To accomplish this the GroupLens system combines your opinions about
+articles you have already read with the opinions of others who have done
+likewise and gives you a personalized prediction for each unread news
+article. Think of GroupLens as a matchmaker. GroupLens watches how you
+rate articles, and finds other people that rate articles the same way.
+Once it has found some people you agree with it tells you, in the form
+of a prediction, what they thought of the article. You can use this
+prediction to help you decide whether or not you want to read the
+article.
+
+@menu
+* Using GroupLens:: How to make Gnus use GroupLens.
+* Rating Articles:: Letting GroupLens know how you rate articles.
+* Displaying Predictions:: Displaying predictions given by GroupLens.
+* GroupLens Variables:: Customizing GroupLens.
+@end menu
+
+
+@node Using GroupLens
+@subsection Using GroupLens
+
+To use GroupLens you must register a pseudonym with your local
+@uref{http://www.cs.umn.edu/Research/GroupLens/bbb.html, Better Bit
+Bureau (BBB)} is the only better bit in town at the moment.
+
+Once you have registered you'll need to set a couple of variables.
+
+@table @code
+
+@item gnus-use-grouplens
+@vindex gnus-use-grouplens
+Setting this variable to a non-@code{nil} value will make Gnus hook into
+all the relevant GroupLens functions.
+
+@item grouplens-pseudonym
+@vindex grouplens-pseudonym
+This variable should be set to the pseudonym you got when registering
+with the Better Bit Bureau.
+
+@item grouplens-newsgroups
+@vindex grouplens-newsgroups
+A list of groups that you want to get GroupLens predictions for.
+
+@end table
+
+That's the minimum of what you need to get up and running with GroupLens.
+Once you've registered, GroupLens will start giving you scores for
+articles based on the average of what other people think. But, to get
+the real benefit of GroupLens you need to start rating articles
+yourself. Then the scores GroupLens gives you will be personalized for
+you, based on how the people you usually agree with have already rated.
+
+
+@node Rating Articles
+@subsection Rating Articles
+
+In GroupLens, an article is rated on a scale from 1 to 5, inclusive.
+Where 1 means something like this article is a waste of bandwidth and 5
+means that the article was really good. The basic question to ask
+yourself is, ``on a scale from 1 to 5 would I like to see more articles
+like this one?''
+
+There are four ways to enter a rating for an article in GroupLens.
+
+@table @kbd
+
+@item r
+@kindex r (GroupLens)
+@findex bbb-summary-rate-article
+This function will prompt you for a rating on a scale of one to five.
+
+@item k
+@kindex k (GroupLens)
+@findex grouplens-score-thread
+This function will prompt you for a rating, and rate all the articles in
+the thread. This is really useful for some of those long running giant
+threads in rec.humor.
+
+@end table
+
+The next two commands, @kbd{n} and @kbd{,} take a numerical prefix to be
+the score of the article you're reading.
+
+@table @kbd
+
+@item 1-5 n
+@kindex n (GroupLens)
+@findex grouplens-next-unread-article
+Rate the article and go to the next unread article.
+
+@item 1-5 ,
+@kindex , (GroupLens)
+@findex grouplens-best-unread-article
+Rate the article and go to the next unread article with the highest score.
+
+@end table
+
+If you want to give the current article a score of 4 and then go to the
+next article, just type @kbd{4 n}.
+
+
+@node Displaying Predictions
+@subsection Displaying Predictions
+
+GroupLens makes a prediction for you about how much you will like a
+news article. The predictions from GroupLens are on a scale from 1 to
+5, where 1 is the worst and 5 is the best. You can use the predictions
+from GroupLens in one of three ways controlled by the variable
+@code{gnus-grouplens-override-scoring}.
+
+@vindex gnus-grouplens-override-scoring
+There are three ways to display predictions in grouplens. You may
+choose to have the GroupLens scores contribute to, or override the
+regular Gnus scoring mechanism. override is the default; however, some
+people prefer to see the Gnus scores plus the grouplens scores. To get
+the separate scoring behavior you need to set
+@code{gnus-grouplens-override-scoring} to @code{'separate}. To have the
+GroupLens predictions combined with the grouplens scores set it to
+@code{'override} and to combine the scores set
+@code{gnus-grouplens-override-scoring} to @code{'combine}. When you use
+the combine option you will also want to set the values for
+@code{grouplens-prediction-offset} and
+@code{grouplens-score-scale-factor}.
+
+@vindex grouplens-prediction-display
+In either case, GroupLens gives you a few choices for how you would like
+to see your predictions displayed. The display of predictions is
+controlled by the @code{grouplens-prediction-display} variable.
+
+The following are valid values for that variable.
+
+@table @code
+@item prediction-spot
+The higher the prediction, the further to the right an @samp{*} is
+displayed.
+
+@item confidence-interval
+A numeric confidence interval.
+
+@item prediction-bar
+The higher the prediction, the longer the bar.
+
+@item confidence-bar
+Numerical confidence.
+
+@item confidence-spot
+The spot gets bigger with more confidence.
+
+@item prediction-num
+Plain-old numeric value.
+
+@item confidence-plus-minus
+Prediction +/- confidence.
+
+@end table
+
+
+@node GroupLens Variables
+@subsection GroupLens Variables
+
+@table @code
+
+@item gnus-summary-grouplens-line-format
+The summary line format used in GroupLens-enhanced summary buffers. It
+accepts the same specs as the normal summary line format (@pxref{Summary
+Buffer Lines}). The default is @samp{%U%R%z%l%I%(%[%4L: %-23,23n%]%)
+%s\n}.
+
+@item grouplens-bbb-host
+Host running the bbbd server. @samp{grouplens.cs.umn.edu} is the
+default.
+
+@item grouplens-bbb-port
+Port of the host running the bbbd server. The default is 9000.
+
+@item grouplens-score-offset
+Offset the prediction by this value. In other words, subtract the
+prediction value by this number to arrive at the effective score. The
+default is 0.
+
+@item grouplens-score-scale-factor
+This variable allows the user to magnify the effect of GroupLens scores.
+The scale factor is applied after the offset. The default is 1.
+
+@end table
+
+
+@node Advanced Scoring
+@section Advanced Scoring
+
+Scoring on Subjects and From headers is nice enough, but what if you're
+really interested in what a person has to say only when she's talking
+about a particular subject? Or what if you really don't want to
+read what person A has to say when she's following up to person B, but
+want to read what she says when she's following up to person C?
+
+By using advanced scoring rules you may create arbitrarily complex
+scoring patterns.
+
+@menu
+* Advanced Scoring Syntax:: A definition.
+* Advanced Scoring Examples:: What they look like.
+* Advanced Scoring Tips:: Getting the most out of it.
+@end menu
+
+
+@node Advanced Scoring Syntax
+@subsection Advanced Scoring Syntax
+
+Ordinary scoring rules have a string as the first element in the rule.
+Advanced scoring rules have a list as the first element. The second
+element is the score to be applied if the first element evaluated to a
+non-@code{nil} value.
+
+These lists may consist of three logical operators, one redirection
+operator, and various match operators.
+
+Logical operators:
+
+@table @code
+@item &
+@itemx and
+This logical operator will evaluate each of its arguments until it finds
+one that evaluates to @code{false}, and then it'll stop. If all arguments
+evaluate to @code{true} values, then this operator will return
+@code{true}.
+
+@item |
+@itemx or
+This logical operator will evaluate each of its arguments until it finds
+one that evaluates to @code{true}. If no arguments are @code{true},
+then this operator will return @code{false}.
+
+@item !
+@itemx not
+@itemx ¬
+This logical operator only takes a single argument. It returns the
+logical negation of the value of its argument.
+
+@end table
+
+There is an @dfn{indirection operator} that will make its arguments
+apply to the ancestors of the current article being scored. For
+instance, @code{1-} will make score rules apply to the parent of the
+current article. @code{2-} will make score rules apply to the
+grandparent of the current article. Alternatively, you can write
+@code{^^}, where the number of @code{^}s (carets) says how far back into
+the ancestry you want to go.
+
+Finally, we have the match operators. These are the ones that do the
+real work. Match operators are header name strings followed by a match
+and a match type. A typical match operator looks like @samp{("from"
+"Lars Ingebrigtsen" s)}. The header names are the same as when using
+simple scoring, and the match types are also the same.
+
+
+@node Advanced Scoring Examples
+@subsection Advanced Scoring Examples
+
+Please note that the following examples are score file rules. To
+make a complete score file from them, surround them with another pair
+of parentheses.
+
+Let's say you want to increase the score of articles written by Lars
+when he's talking about Gnus:
+
+@example
+@group
+((&
+ ("from" "Lars Ingebrigtsen")
+ ("subject" "Gnus"))
+ 1000)
+@end group
+@end example
+
+Quite simple, huh?
+
+When he writes long articles, he sometimes has something nice to say:
+
+@example
+((&
+ ("from" "Lars Ingebrigtsen")
+ (|
+ ("subject" "Gnus")
+ ("lines" 100 >)))
+ 1000)
+@end example
+
+However, when he responds to things written by Reig Eigil Logge, you
+really don't want to read what he's written:
+
+@example
+((&
+ ("from" "Lars Ingebrigtsen")
+ (1- ("from" "Reig Eigir Logge")))
+ -100000)
+@end example
+
+Everybody that follows up Redmondo when he writes about disappearing
+socks should have their scores raised, but only when they talk about
+white socks. However, when Lars talks about socks, it's usually not
+very interesting:
+
+@example
+((&
+ (1-
+ (&
+ ("from" "redmondo@@.*no" r)
+ ("body" "disappearing.*socks" t)))
+ (! ("from" "Lars Ingebrigtsen"))
+ ("body" "white.*socks"))
+ 1000)
+@end example
+
+The possibilities are endless.
+
+
+@node Advanced Scoring Tips
+@subsection Advanced Scoring Tips
+
+The @code{&} and @code{|} logical operators do short-circuit logic.
+That is, they stop processing their arguments when it's clear what the
+result of the operation will be. For instance, if one of the arguments
+of an @code{&} evaluates to @code{false}, there's no point in evaluating
+the rest of the arguments. This means that you should put slow matches
+(@samp{body}, @samp{header}) last and quick matches (@samp{from},
+@samp{subject}) first.
+
+The indirection arguments (@code{1-} and so on) will make their
+arguments work on previous generations of the thread. If you say
+something like:
+
+@example
+...
+(1-
+ (1-
+ ("from" "lars")))
+...
+@end example
+
+Then that means "score on the from header of the grandparent of the
+current article". An indirection is quite fast, but it's better to say:
+
+@example
+(1-
+ (&
+ ("from" "Lars")
+ ("subject" "Gnus")))
+@end example
+
+than it is to say:
+
+@example
+(&
+ (1- ("from" "Lars"))
+ (1- ("subject" "Gnus")))
+@end example
+
+
+@node Score Decays
+@section Score Decays
+@cindex score decays
+@cindex decays
+
+You may find that your scores have a tendency to grow without
+bounds, especially if you're using adaptive scoring. If scores get too
+big, they lose all meaning---they simply max out and it's difficult to
+use them in any sensible way.
+
+@vindex gnus-decay-scores
+@findex gnus-decay-score
+@vindex gnus-decay-score-function
+Gnus provides a mechanism for decaying scores to help with this problem.
+When score files are loaded and @code{gnus-decay-scores} is
+non-@code{nil}, Gnus will run the score files through the decaying
+mechanism thereby lowering the scores of all non-permanent score rules.
+The decay itself if performed by the @code{gnus-decay-score-function}
+function, which is @code{gnus-decay-score} by default. Here's the
+definition of that function:
+
+@lisp
+(defun gnus-decay-score (score)
+ "Decay SCORE according to `gnus-score-decay-constant'
+and `gnus-score-decay-scale'."
+ (let ((n (- score
+ (* (if (< score 0) -1 1)
+ (min (abs score)
+ (max gnus-score-decay-constant
+ (* (abs score)
+ gnus-score-decay-scale)))))))
+ (if (and (featurep 'xemacs)
+ ;; XEmacs' floor can handle only the floating point
+ ;; number below the half of the maximum integer.
+ (> (abs n) (lsh -1 -2)))
+ (string-to-number
+ (car (split-string (number-to-string n) "\\.")))
+ (floor n))))
+@end lisp
+
+@vindex gnus-score-decay-scale
+@vindex gnus-score-decay-constant
+@code{gnus-score-decay-constant} is 3 by default and
+@code{gnus-score-decay-scale} is 0.05. This should cause the following:
+
+@enumerate
+@item
+Scores between -3 and 3 will be set to 0 when this function is called.
+
+@item
+Scores with magnitudes between 3 and 60 will be shrunk by 3.
+
+@item
+Scores with magnitudes greater than 60 will be shrunk by 5% of the
+score.
+@end enumerate
+
+If you don't like this decay function, write your own. It is called
+with the score to be decayed as its only parameter, and it should return
+the new score, which should be an integer.
+
+Gnus will try to decay scores once a day. If you haven't run Gnus for
+four days, Gnus will decay the scores four times, for instance.
+
+@iftex
+@iflatex
+@chapter Message
+@include message.texi
+@chapter Emacs MIME
+@include emacs-mime.texi
+@chapter Sieve
+@include sieve.texi
+@c @chapter PGG
+@c @include pgg.texi
+@end iflatex
+@end iftex
+
+@node Various
+@chapter Various
+
+@menu
+* Process/Prefix:: A convention used by many treatment commands.
+* Interactive:: Making Gnus ask you many questions.
+* Symbolic Prefixes:: How to supply some Gnus functions with options.
+* Formatting Variables:: You can specify what buffers should look like.
+* Window Layout:: Configuring the Gnus buffer windows.
+* Faces and Fonts:: How to change how faces look.
+* Compilation:: How to speed Gnus up.
+* Mode Lines:: Displaying information in the mode lines.
+* Highlighting and Menus:: Making buffers look all nice and cozy.
+* Buttons:: Get tendinitis in ten easy steps!
+* Daemons:: Gnus can do things behind your back.
+* NoCeM:: How to avoid spam and other fatty foods.
+* Undo:: Some actions can be undone.
+* Predicate Specifiers:: Specifying predicates.
+* Moderation:: What to do if you're a moderator.
+* Image Enhancements:: Modern versions of Emacs/XEmacs can display images.
+* Fuzzy Matching:: What's the big fuzz?
+* Thwarting Email Spam:: A how-to on avoiding unsolicited commercial email.
+* Other modes:: Interaction with other modes.
+* Various Various:: Things that are really various.
+@end menu
+
+
+@node Process/Prefix
+@section Process/Prefix
+@cindex process/prefix convention
+
+Many functions, among them functions for moving, decoding and saving
+articles, use what is known as the @dfn{Process/Prefix convention}.
+
+This is a method for figuring out what articles the user wants the
+command to be performed on.
+
+It goes like this:
+
+If the numeric prefix is N, perform the operation on the next N
+articles, starting with the current one. If the numeric prefix is
+negative, perform the operation on the previous N articles, starting
+with the current one.
+
+@vindex transient-mark-mode
+If @code{transient-mark-mode} in non-@code{nil} and the region is
+active, all articles in the region will be worked upon.
+
+If there is no numeric prefix, but some articles are marked with the
+process mark, perform the operation on the articles marked with
+the process mark.
+
+If there is neither a numeric prefix nor any articles marked with the
+process mark, just perform the operation on the current article.
+
+Quite simple, really, but it needs to be made clear so that surprises
+are avoided.
+
+Commands that react to the process mark will push the current list of
+process marked articles onto a stack and will then clear all process
+marked articles. You can restore the previous configuration with the
+@kbd{M P y} command (@pxref{Setting Process Marks}).
+
+@vindex gnus-summary-goto-unread
+One thing that seems to shock & horrify lots of people is that, for
+instance, @kbd{3 d} does exactly the same as @kbd{d} @kbd{d} @kbd{d}.
+Since each @kbd{d} (which marks the current article as read) by default
+goes to the next unread article after marking, this means that @kbd{3 d}
+will mark the next three unread articles as read, no matter what the
+summary buffer looks like. Set @code{gnus-summary-goto-unread} to
+@code{nil} for a more straightforward action.
+
+Many commands do not use the process/prefix convention. All commands
+that do explicitly say so in this manual. To apply the process/prefix
+convention to commands that do not use it, you can use the @kbd{M-&}
+command. For instance, to mark all the articles in the group as
+expirable, you could say @kbd{M P b M-& E}.
+
+
+@node Interactive
+@section Interactive
+@cindex interaction
+
+@table @code
+
+@item gnus-novice-user
+@vindex gnus-novice-user
+If this variable is non-@code{nil}, you are either a newcomer to the
+World of Usenet, or you are very cautious, which is a nice thing to be,
+really. You will be given questions of the type ``Are you sure you want
+to do this?'' before doing anything dangerous. This is @code{t} by
+default.
+
+@item gnus-expert-user
+@vindex gnus-expert-user
+If this variable is non-@code{nil}, you will seldom be asked any
+questions by Gnus. It will simply assume you know what you're doing, no
+matter how strange.
+
+@item gnus-interactive-catchup
+@vindex gnus-interactive-catchup
+Require confirmation before catching up a group if non-@code{nil}. It
+is @code{t} by default.
+
+@item gnus-interactive-exit
+@vindex gnus-interactive-exit
+Require confirmation before exiting Gnus. This variable is @code{t} by
+default.
+@end table
+
+
+@node Symbolic Prefixes
+@section Symbolic Prefixes
+@cindex symbolic prefixes
+
+Quite a lot of Emacs commands react to the (numeric) prefix. For
+instance, @kbd{C-u 4 C-f} moves point four characters forward, and
+@kbd{C-u 9 0 0 I s s p} adds a permanent @code{Subject} substring score
+rule of 900 to the current article.
+
+This is all nice and well, but what if you want to give a command some
+additional information? Well, what most commands do is interpret the
+``raw'' prefix in some special way. @kbd{C-u 0 C-x C-s} means that one
+doesn't want a backup file to be created when saving the current buffer,
+for instance. But what if you want to save without making a backup
+file, and you want Emacs to flash lights and play a nice tune at the
+same time? You can't, and you're probably perfectly happy that way.
+
+@kindex M-i (Summary)
+@findex gnus-symbolic-argument
+I'm not, so I've added a second prefix---the @dfn{symbolic prefix}. The
+prefix key is @kbd{M-i} (@code{gnus-symbolic-argument}), and the next
+character typed in is the value. You can stack as many @kbd{M-i}
+prefixes as you want. @kbd{M-i a C-M-u} means ``feed the @kbd{C-M-u}
+command the symbolic prefix @code{a}''. @kbd{M-i a M-i b C-M-u} means
+``feed the @kbd{C-M-u} command the symbolic prefixes @code{a} and
+@code{b}''. You get the drift.
+
+Typing in symbolic prefixes to commands that don't accept them doesn't
+hurt, but it doesn't do any good either. Currently not many Gnus
+functions make use of the symbolic prefix.
+
+If you're interested in how Gnus implements this, @pxref{Extended
+Interactive}.
+
+
+@node Formatting Variables
+@section Formatting Variables
+@cindex formatting variables
+
+Throughout this manual you've probably noticed lots of variables called
+things like @code{gnus-group-line-format} and
+@code{gnus-summary-mode-line-format}. These control how Gnus is to
+output lines in the various buffers. There's quite a lot of them.
+Fortunately, they all use the same syntax, so there's not that much to
+be annoyed by.
+
+Here's an example format spec (from the group buffer): @samp{%M%S%5y:
+%(%g%)\n}. We see that it is indeed extremely ugly, and that there are
+lots of percentages everywhere.
+
+@menu
+* Formatting Basics:: A formatting variable is basically a format string.
+* Mode Line Formatting:: Some rules about mode line formatting variables.
+* Advanced Formatting:: Modifying output in various ways.
+* User-Defined Specs:: Having Gnus call your own functions.
+* Formatting Fonts:: Making the formatting look colorful and nice.
+* Positioning Point:: Moving point to a position after an operation.
+* Tabulation:: Tabulating your output.
+* Wide Characters:: Dealing with wide characters.
+@end menu
+
+Currently Gnus uses the following formatting variables:
+@code{gnus-group-line-format}, @code{gnus-summary-line-format},
+@code{gnus-server-line-format}, @code{gnus-topic-line-format},
+@code{gnus-group-mode-line-format},
+@code{gnus-summary-mode-line-format},
+@code{gnus-article-mode-line-format},
+@code{gnus-server-mode-line-format}, and
+@code{gnus-summary-pick-line-format}.
+
+All these format variables can also be arbitrary elisp forms. In that
+case, they will be @code{eval}ed to insert the required lines.
+
+@kindex M-x gnus-update-format
+@findex gnus-update-format
+Gnus includes a command to help you while creating your own format
+specs. @kbd{M-x gnus-update-format} will @code{eval} the current form,
+update the spec in question and pop you to a buffer where you can
+examine the resulting Lisp code to be run to generate the line.
+
+
+
+@node Formatting Basics
+@subsection Formatting Basics
+
+Each @samp{%} element will be replaced by some string or other when the
+buffer in question is generated. @samp{%5y} means ``insert the @samp{y}
+spec, and pad with spaces to get a 5-character field''.
+
+As with normal C and Emacs Lisp formatting strings, the numerical
+modifier between the @samp{%} and the formatting type character will
+@dfn{pad} the output so that it is always at least that long.
+@samp{%5y} will make the field always (at least) five characters wide by
+padding with spaces to the left. If you say @samp{%-5y}, it will pad to
+the right instead.
+
+You may also wish to limit the length of the field to protect against
+particularly wide values. For that you can say @samp{%4,6y}, which
+means that the field will never be more than 6 characters wide and never
+less than 4 characters wide.
+
+Also Gnus supports some extended format specifications, such as
+@samp{%&user-date;}.
+
+
+@node Mode Line Formatting
+@subsection Mode Line Formatting
+
+Mode line formatting variables (e.g.,
+@code{gnus-summary-mode-line-format}) follow the same rules as other,
+buffer line oriented formatting variables (@pxref{Formatting Basics})
+with the following two differences:
+
+@enumerate
+
+@item
+There must be no newline (@samp{\n}) at the end.
+
+@item
+The special @samp{%%b} spec can be used to display the buffer name.
+Well, it's no spec at all, really---@samp{%%} is just a way to quote
+@samp{%} to allow it to pass through the formatting machinery unmangled,
+so that Emacs receives @samp{%b}, which is something the Emacs mode line
+display interprets to mean ``show the buffer name''. For a full list of
+mode line specs Emacs understands, see the documentation of the
+@code{mode-line-format} variable.
+
+@end enumerate
+
+
+@node Advanced Formatting
+@subsection Advanced Formatting
+
+It is frequently useful to post-process the fields in some way.
+Padding, limiting, cutting off parts and suppressing certain values can
+be achieved by using @dfn{tilde modifiers}. A typical tilde spec might
+look like @samp{%~(cut 3)~(ignore "0")y}.
+
+These are the valid modifiers:
+
+@table @code
+@item pad
+@itemx pad-left
+Pad the field to the left with spaces until it reaches the required
+length.
+
+@item pad-right
+Pad the field to the right with spaces until it reaches the required
+length.
+
+@item max
+@itemx max-left
+Cut off characters from the left until it reaches the specified length.
+
+@item max-right
+Cut off characters from the right until it reaches the specified
+length.
+
+@item cut
+@itemx cut-left
+Cut off the specified number of characters from the left.
+
+@item cut-right
+Cut off the specified number of characters from the right.
+
+@item ignore
+Return an empty string if the field is equal to the specified value.
+
+@item form
+Use the specified form as the field value when the @samp{@@} spec is
+used.
+
+Here's an example:
+
+@lisp
+"~(form (current-time-string))@@"
+@end lisp
+
+@end table
+
+Let's take an example. The @samp{%o} spec in the summary mode lines
+will return a date in compact ISO8601 format---@samp{19960809T230410}.
+This is quite a mouthful, so we want to shave off the century number and
+the time, leaving us with a six-character date. That would be
+@samp{%~(cut-left 2)~(max-right 6)~(pad 6)o}. (Cutting is done before
+maxing, and we need the padding to ensure that the date is never less
+than 6 characters to make it look nice in columns.)
+
+Ignoring is done first; then cutting; then maxing; and then as the very
+last operation, padding.
+
+@vindex gnus-compile-user-specs
+If @code{gnus-compile-user-specs} is set to @code{nil} (@code{t} by
+default) with your strong personality, and use a lots of these advanced
+thingies, you'll find that Gnus gets quite slow. This can be helped
+enormously by running @kbd{M-x gnus-compile} when you are satisfied with
+the look of your lines.
+@xref{Compilation}.
+
+
+@node User-Defined Specs
+@subsection User-Defined Specs
+
+All the specs allow for inserting user defined specifiers---@samp{u}.
+The next character in the format string should be a letter. 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
+a single parameter---what the parameter means depends on what buffer
+it's being called from. The function should return a string, which will
+be inserted into the buffer just like information from any other
+specifier. This function may also be called with dummy values, so it
+should protect against that.
+
+Also Gnus supports extended user-defined specs, such as @samp{%u&foo;}.
+Gnus will call the function @code{gnus-user-format-function-}@samp{foo}.
+
+You can also use tilde modifiers (@pxref{Advanced Formatting} to achieve
+much the same without defining new functions. Here's an example:
+@samp{%~(form (count-lines (point-min) (point)))@@}. The form
+given here will be evaluated to yield the current line number, and then
+inserted.
+
+
+@node Formatting Fonts
+@subsection Formatting Fonts
+
+There are specs for highlighting, and these are shared by all the format
+variables. Text inside the @samp{%(} and @samp{%)} specifiers will get
+the special @code{mouse-face} property set, which means that it will be
+highlighted (with @code{gnus-mouse-face}) when you put the mouse pointer
+over it.
+
+Text inside the @samp{%@{} and @samp{%@}} specifiers will have their
+normal faces set using @code{gnus-face-0}, which is @code{bold} by
+default. If you say @samp{%1@{}, you'll get @code{gnus-face-1} instead,
+and so on. Create as many faces as you wish. The same goes for the
+@code{mouse-face} specs---you can say @samp{%3(hello%)} to have
+@samp{hello} mouse-highlighted with @code{gnus-mouse-face-3}.
+
+Text inside the @samp{%<<} and @samp{%>>} specifiers will get the
+special @code{balloon-help} property set to
+@code{gnus-balloon-face-0}. If you say @samp{%1<<}, you'll get
+@code{gnus-balloon-face-1} and so on. The @code{gnus-balloon-face-*}
+variables should be either strings or symbols naming functions that
+return a string. When the mouse passes over text with this property
+set, a balloon window will appear and display the string. Please
+refer to @ref{Tooltips, ,Tooltips, emacs, The Emacs Manual},
+(in GNU Emacs) or the doc string of @code{balloon-help-mode} (in
+XEmacs) for more information on this. (For technical reasons, the
+guillemets have been approximated as @samp{<<} and @samp{>>} in this
+paragraph.)
+
+Here's an alternative recipe for the group buffer:
+
+@lisp
+;; @r{Create three face types.}
+(setq gnus-face-1 'bold)
+(setq gnus-face-3 'italic)
+
+;; @r{We want the article count to be in}
+;; @r{a bold and green face. So we create}
+;; @r{a new face called @code{my-green-bold}.}
+(copy-face 'bold 'my-green-bold)
+;; @r{Set the color.}
+(set-face-foreground 'my-green-bold "ForestGreen")
+(setq gnus-face-2 'my-green-bold)
+
+;; @r{Set the new & fancy format.}
+(setq gnus-group-line-format
+ "%M%S%3@{%5y%@}%2[:%] %(%1@{%g%@}%)\n")
+@end lisp
+
+I'm sure you'll be able to use this scheme to create totally unreadable
+and extremely vulgar displays. Have fun!
+
+Note that the @samp{%(} specs (and friends) do not make any sense on the
+mode-line variables.
+
+@node Positioning Point
+@subsection Positioning Point
+
+Gnus usually moves point to a pre-defined place on each line in most
+buffers. By default, point move to the first colon character on the
+line. You can customize this behaviour in three different ways.
+
+You can move the colon character to somewhere else on the line.
+
+@findex gnus-goto-colon
+You can redefine the function that moves the point to the colon. The
+function is called @code{gnus-goto-colon}.
+
+But perhaps the most convenient way to deal with this, if you don't want
+to have a colon in your line, is to use the @samp{%*} specifier. If you
+put a @samp{%*} somewhere in your format line definition, Gnus will
+place point there.
+
+
+@node Tabulation
+@subsection Tabulation
+
+You can usually line up your displays by padding and cutting your
+strings. However, when combining various strings of different size, it
+can often be more convenient to just output the strings, and then worry
+about lining up the following text afterwards.
+
+To do that, Gnus supplies tabulator specs---@samp{%=}. There are two
+different types---@dfn{hard tabulators} and @dfn{soft tabulators}.
+
+@samp{%50=} will insert space characters to pad the line up to column
+50. If the text is already past column 50, nothing will be inserted.
+This is the soft tabulator.
+
+@samp{%-50=} will insert space characters to pad the line up to column
+50. If the text is already past column 50, the excess text past column
+50 will be removed. This is the hard tabulator.
+
+
+@node Wide Characters
+@subsection Wide Characters
+
+Fixed width fonts in most countries have characters of the same width.
+Some countries, however, use Latin characters mixed with wider
+characters---most notable East Asian countries.
+
+The problem is that when formatting, Gnus assumes that if a string is 10
+characters wide, it'll be 10 Latin characters wide on the screen. In
+these countries, that's not true.
+
+@vindex gnus-use-correct-string-widths
+To help fix this, you can set @code{gnus-use-correct-string-widths} to
+@code{t}. This makes buffer generation slower, but the results will be
+prettier. The default value under XEmacs is @code{t} but @code{nil}
+for Emacs.
+
+
+@node Window Layout
+@section Window Layout
+@cindex window layout
+
+No, there's nothing here about X, so be quiet.
+
+@vindex gnus-use-full-window
+If @code{gnus-use-full-window} non-@code{nil}, Gnus will delete all
+other windows and occupy the entire Emacs screen by itself. It is
+@code{t} by default.
+
+Setting this variable to @code{nil} kinda works, but there are
+glitches. Use at your own peril.
+
+@vindex gnus-buffer-configuration
+@code{gnus-buffer-configuration} describes how much space each Gnus
+buffer should be given. Here's an excerpt of this variable:
+
+@lisp
+((group (vertical 1.0 (group 1.0 point)
+ (if gnus-carpal (group-carpal 4))))
+ (article (vertical 1.0 (summary 0.25 point)
+ (article 1.0))))
+@end lisp
+
+This is an alist. The @dfn{key} is a symbol that names some action or
+other. For instance, when displaying the group buffer, the window
+configuration function will use @code{group} as the key. A full list of
+possible names is listed below.