gnus-summary-line-format

gnus-summary-line-format is a variable defined in `gnus.el'.
Its value is

"%U%R%z%I%(%[%4L: %-23,23f%]%) %s
"

Documentation:
*The format specification of the lines in the summary buffer.

It works along the same lines as a normal formatting string,
with some simple extensions.

%N Article number, left padded with spaces (string)
%S Subject (string)
%s Subject if it is at the root of a thread, and ""
otherwise (string)
%n Name of the poster (string)
%a Extracted name of the poster (string)
%A Extracted address of the poster (string)
%F Contents of the From: header (string)
%f Contents of the From: or To: headers (string)
%x Contents of the Xref: header (string)
%D Date of the article (string)
%d Date of the article (string) in DD-MMM format
%o Date of the article (string) in YYYYMMDD`T'HHMMSS
format
%M Message-id of the article (string)
%r References of the article (string)
%c Number of characters in the article (integer)
%k Pretty-printed version of the above (string)
For example, "1.2k" or "0.4M".
%L Number of lines in the article (integer)
%I Indentation based on thread level (a string of
spaces)
%B A complex trn-style thread tree (string)
The variables `gnus-sum-thread-*' can be used for
customization.
%T A string with two possible values: 80 spaces if the
article is on thread level two or larger and 0 spaces
on level one
%R "A" if this article has been replied to, " "
otherwise (character)
%U "Read" status of this article.
See Info node `(gnus)Marking Articles'
%[ Opening bracket (character, "[" or "<")
%] Closing bracket (character, "]" or ">")
%> Spaces of length thread-level (string)
%< Spaces of length (- 20 thread-level) (string)
%i Article score (number)
%z Article zcore (character)
%t Number of articles under the current thread (number).
%e Whether the thread is empty or not (character).
%V Total thread score (number).
%P The line number (number).
%O Download mark (character).
%* If present, indicates desired cursor position
(instead of after first colon).
%u User defined specifier. The next character in the
format string should be a letter. Gnus will call the
function gnus-user-format-function-X, where X is the
letter following %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.
&user-date; Age sensitive date format. Various date format is
defined in `gnus-user-date-format-alist'.


The %U (status), %R (replied) and %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.

This restriction may disappear in later versions of Gnus.

General format specifiers can also be used.
See Info node `(gnus)Formatting Variables'.

You can customize this variable.