You can change the format of the lines in the summary buffer by changing
the gnus-summary-line-format variable. It works along the same
lines as a normal format string, with some extensions
(see Formatting Variables).
There should always be a colon or a point position marker on the line;
the cursor always moves to the point position marker or the colon after
performing an operation. (Of course, Gnus wouldn’t be Gnus if it wasn’t
possible to change this. Just write a new function
gnus-goto-colon which does whatever you like with the cursor.)
See Positioning Point.
The default string is ‘%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n’.
The following format specification characters and extended format specification(s) are understood:
Article number.
Subject string. List identifiers stripped,
gnus-list-identifiers. See Article Hiding.
Subject if the article is the root of the thread or the previous article
had a different subject, gnus-summary-same-subject otherwise.
(gnus-summary-same-subject defaults to "".)
Full From header.
The name (from the From header).
The name, To header or the Newsgroups header (see To From Newsgroups).
The name (from the From header). This differs from the n
spec in that it uses the function designated by the
gnus-extract-address-components variable, which is slower, but
may be more thorough.
The address (from the From header). This works the same way as
the a spec.
Number of lines in the article.
Retrieval Score Value (RSV) of the article; nil if not in an
nnselect group.
Originating group name of the article; nil if not in an
nnselect group.
Short form of the originating group name of the article; nil if
not in an nnselect group.
Number of characters in the article. This specifier is not supported in some methods (like nnfolder).
Pretty-printed version of the number of characters in the article; for example, ‘1.2k’ or ‘0.4M’.
Indentation based on thread level (see Customizing Threading).
A complex trn-style thread tree, showing response-connecting trace lines. A thread could be drawn like this:
> +-> | +-> | | \-> | | \-> | \-> +-> \->
You can customize the appearance with the following options. Note that it is possible to make the thread display look really neat by replacing the default ASCII characters with graphic line-drawing glyphs.
gnus-sum-thread-tree-root ¶Used for the root of a thread. If nil, use subject
instead. The default is ‘> ’.
gnus-sum-thread-tree-false-root ¶Used for the false root of a thread (see Loose Threads). If
nil, use subject instead. The default is ‘> ’.
gnus-sum-thread-tree-single-indent ¶Used for a thread with just one message. If nil, use subject
instead. The default is ‘’.
gnus-sum-thread-tree-vertical ¶Used for drawing a vertical line. The default is ‘| ’.
gnus-sum-thread-tree-indent ¶Used for indenting. The default is ‘ ’.
gnus-sum-thread-tree-leaf-with-other ¶Used for a leaf with brothers. The default is ‘+-> ’.
gnus-sum-thread-tree-single-leaf ¶Used for a leaf without brothers. The default is ‘\-> ’
Nothing if the article is a root and lots of spaces if it isn’t (it pushes everything after it off the screen).
Opening bracket, which is normally ‘[’, but can also be ‘<’ for adopted articles (see Customizing Threading). This can be customized using following settings:
Closing bracket, which is normally ‘]’, but can also be ‘>’ for adopted articles. This can be customized using following settings:
One space for each thread level.
Twenty minus thread level spaces.
Unread. See Read Articles.
This misleadingly named specifier is the secondary mark. This mark will say whether the article has been replied to, has been cached, or has been saved. See Other Marks.
Score as a number (see Scoring).
Zcore, ‘+’ if above the default level and ‘-’ if below the
default level. If the difference between
gnus-summary-default-score and the score is less than
gnus-summary-zcore-fuzz, this spec will not be used.
Total thread score.
Xref.
Date.
The Date in DD-MMM format.
The Date in YYYYMMDDTHHMMSS format.
Message-ID.
References.
Number of articles in the current sub-thread. Using this spec will slow down summary buffer generation somewhat.
An ‘=’ (gnus-not-empty-thread-mark) will be displayed if the
article has any children.
The line number.
Download mark.
Desired cursor position (instead of after first colon).
Age sensitive date format. Various date format is defined in
gnus-user-date-format-alist.
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.
Text between ‘%(’ and ‘%)’ will be highlighted with
gnus-mouse-face when the mouse point is placed inside the area.
There can only be one such area.
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. (Isn’t that the case with everything, though? But I digress.)
This restriction may disappear in later versions of Gnus.