-@end table
-
-@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 (@pxref{Customizing Threading}).
-@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. @xref{Read Articles}.
-
-@item R
-This misleadingly named specifier is the @dfn{secondary mark}. This
-mark will say whether the article has been replied to, has been cached,
-or has been saved. @xref{Other Marks}.
-
-@item i
-Score as a number (@pxref{Scoring}).
-@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-score} 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 d
-The @code{Date} in @code{DD-MMM} format.
-@item o
-The @code{Date} in @var{YYYYMMDD}@code{T}@var{HHMMSS} format.
-@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
-An @samp{=} (@code{gnus-not-empty-thread-mark}) will be displayed if the
-article has any children.
-@item P
-The line number.
-@item O
-Download mark.
-@item *
-Desired cursor position (instead of after first colon).
-@item &user-date;
-Age sensitive date format. Various date format is defined in
-@code{gnus-user-date-format-alist}.
-@item u
-User defined specifier. The next character in the format string should
-be a letter. Gnus will call the function
-@code{gnus-user-format-function-@var{x}}, where @var{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
-
-Text between @samp{%(} and @samp{%)} will be highlighted with
-@code{gnus-mouse-face} when the mouse point is placed inside the area.
-There can only be one such area.
-
-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 invalid 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 To From Newsgroups
-@subsection To From Newsgroups
-@cindex To
-@cindex Newsgroups
-
-In some groups (particularly in archive groups), the @code{From} header
-isn't very interesting, since all the articles there are written by
-you. To display the information in the @code{To} or @code{Newsgroups}
-headers instead, you need to decide three things: What information to
-gather; where to display it; and when to display it.
-
-@enumerate
-@item
-@vindex gnus-extra-headers
-The reading of extra header information is controlled by the
-@code{gnus-extra-headers}. This is a list of header symbols. For
-instance:
-
-@lisp
-(setq gnus-extra-headers
- '(To Newsgroups X-Newsreader))
-@end lisp
-
-This will result in Gnus trying to obtain these three headers, and
-storing it in header structures for later easy retrieval.
-
-@item
-@findex gnus-extra-header
-The value of these extra headers can be accessed via the
-@code{gnus-extra-header} function. Here's a format line spec that will
-access the @code{X-Newsreader} header:
-
-@example
-"%~(form (gnus-extra-header 'X-Newsreader))@@"
-@end example
-
-@item
-@vindex gnus-ignored-from-addresses
-The @code{gnus-ignored-from-addresses} variable says when the @samp{%f}
-summary line spec returns the @code{To}, @code{Newsreader} or
-@code{From} header. If this regexp matches the contents of the
-@code{From} header, the value of the @code{To} or @code{Newsreader}
-headers are used instead.
-
-To distinguish regular articles from those where the @code{From} field
-has been swapped, a string is prefixed to the @code{To} or
-@code{Newsgroups} header in the summary line. By default the string is
-@samp{-> } for @code{To} and @samp{=> } for @code{Newsgroups}, you can
-customize these strings with @code{gnus-summary-to-prefix} and
-@code{gnus-summary-newsgroup-prefix}.
-
-@end enumerate
-
-@vindex nnmail-extra-headers
-A related variable is @code{nnmail-extra-headers}, which controls when
-to include extra headers when generating overview (@acronym{NOV}) files.
-If you have old overview files, you should regenerate them after
-changing this variable, by entering the server buffer using @kbd{^},
-and then @kbd{g} on the appropriate mail server (e.g. nnml) to cause
-regeneration.
-
-@vindex gnus-summary-line-format
-You also have to instruct Gnus to display the data by changing the
-@code{%n} spec to the @code{%f} spec in the
-@code{gnus-summary-line-format} variable.