@item background-pixmap
The pixmap displayed in the background of the face. Only used by faces
-on X devices.
+on GUI devices, currently X11, GTK, and Microsoft Windows.
@item underline
Underline all text covered by this face.
be a list of the form @code{(@var{width} @var{height} @var{data})} where
@var{width} and @var{height} are the size in pixels, and @var{data} is a
string, containing the raw bits of the bitmap.
+
+Similarly to how the glyph's image specifier works @xref{Creating
+Glyphs}, you don't create your own image specifier, but rather add
+specifications to the existing one. Note that the image instance that is
+generated in order to actually display the background pixmap is of type
+@code{mono-pixmap}, meaning that it's a two-color image and the
+foreground and background of the image get filled in with the
+corresponding colors from the face. (#### Is this still true?)
@end deffn
@deffn Command set-face-font face font &optional locale tag-set how-to-add
@end defun
@defun face-background-pixmap face &optional locale tag-set exact-p
-This function return the background-pixmap glyph object of face
+This function returns the background-pixmap image specifier of face
@var{face}.
@end defun