(Composite Types): Document `group' type.

lispref/ChangeLog

+2007-11-29  Richard Stallman  <rms@gnu.org>
+
+	* customize.texi (Composite Types): Document `group' type.
+
 2007-11-24  Richard Stallman  <rms@gnu.org>
 
 	* display.texi (Refresh Screen, Forcing Redisplay): 

lispref/customize.texi

@@ -747,6 +747,11 @@ string, and the third a function.
 In the customization buffer, each element is displayed and edited
 separately, according to the type specified for it.
 
+@item (group @var{element-types}@dots{})
+This works like @code{list} except for the formatting
+of text in the Custom buffer.  @code{list} labels each
+element value with its tag; @code{group} does not.
+
 @item (vector @var{element-types}@dots{})
 Like @code{list} except that the value must be a vector instead of a
 list.  The elements work the same as in @code{list}.