Group Highlighting
------------------

   Highlighting in the group buffer is controlled by the
`gnus-group-highlight' variable.  This is an alist with elements that
look like (FORM . FACE).  If FORM evaluates to something non-`nil', the
FACE will be used on the line.

   Here's an example value for this variable that might look nice if the
background is dark:

     (setq gnus-group-highlight
         `(((> unread 200) .
            ,(custom-face-lookup "Red" nil nil t nil nil))
           ((and (< level 3) (zerop unread)) .
            ,(custom-face-lookup "SeaGreen" nil nil t nil nil))
           ((< level 3) .
            ,(custom-face-lookup "SpringGreen" nil nil t nil nil))
           ((zerop unread) .
            ,(custom-face-lookup "SteelBlue" nil nil t nil nil))
           (t .
            ,(custom-face-lookup "SkyBlue" nil nil t nil nil))
           ))

   Variables that are dynamically bound when the forms are evaluated
include:

`group'
     The group name.

`unread'
     The number of unread articles in the group.

`method'
     The select method.

`mailp'
     Whether the group is a mail group.

`level'
     The level of the group.

`score'
     The score of the group.

`ticked'
     The number of ticked articles in the group.

`topic'
     When using the topic minor mode, this variable is bound to the
     current topic being inserted.

   When the forms are `eval'ed, point is at the beginning of the line
of the group in question, so you can use many of the normal Gnus
functions for snarfing info on the group.

   `gnus-group-update-hook' is called when a group line is changed.  It
will not be called when `gnus-visual' is `nil'.  This hook calls
`gnus-group-highlight-line' by default.