-@item gnus-sum-thread-tree-single-leaf
-@vindex gnus-sum-thread-tree-single-leaf
-Used for a leaf without brothers. The default is @samp{\-> }
-
-@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.