Smiley is a package separate from Gnus, but since Gnus is currently the only package that uses Smiley, it is documented here.
In short—to use Smiley in Gnus, put the following in your ~/.gnus.el file:
(setq gnus-treat-display-smileys t)
Smiley maps text smiley faces—‘:-)’, ‘8-)’, ‘:-(’ and the like—to pictures and displays those instead of the text smiley faces. The conversion is controlled by a list of regexps that matches text and maps that to file names.
The alist used is
specified by the smiley-regexp-alist variable. The
first item in each element is the regexp to be matched; the
second element is the regexp match group that is to be replaced
by the picture; and the third element is the name of the file to
be displayed.
The following variables customize the appearance of the smileys:
smiley-stylelow-color (small
13x14 pixel, three-color images), medium (more
colorful images, 16x16 pixel), and grayscale
(grayscale images, 14x14 pixel). The default depends on the
height of the default face.smiley-data-directorysmiley-style
instead.gnus-smiley-file-types