--- a/src/specifier.c	Mon Aug 13 11:15:00 2007 +0200
+++ b/src/specifier.c	Mon Aug 13 11:16:07 2007 +0200
@@ -543,12 +543,14 @@
 
 TYPE specifies the particular type of specifier, and should be one of
 the symbols 'generic, 'integer, 'boolean, 'color, 'font, 'image,
-'face-boolean, or 'toolbar.
-
-For more information on particular types of specifiers, see the functions
-`generic-specifier-p', `integer-specifier-p', `boolean-specifier-p',
-`color-specifier-p', `font-specifier-p', `image-specifier-p',
-`face-boolean-specifier-p', and `toolbar-specifier-p'.
+'face-boolean, 'gutter, 'gutter-size, 'gutter-visible or 'toolbar.
+
+For more information on particular types of specifiers, see the
+functions `generic-specifier-p', `integer-specifier-p',
+`boolean-specifier-p', `color-specifier-p', `font-specifier-p',
+`image-specifier-p', `face-boolean-specifier-p', `gutter-specifier-p,
+`gutter-size-specifier-p, `gutter-visible-specifier-p and
+`toolbar-specifier-p'.
 */
        (type))
 {
@@ -2816,6 +2818,13 @@
      method. */
   location = (Lisp_Object *)
     ((char *) w + XSPECIFIER (specifier)->caching->offset_into_struct_window);
+  /* #### What's the point of this check, other than to optimize image
+     instance instantiation? Unless you specify a caching instantiate
+     method the instantiation that specifier_instance will do will
+     always create a new copy. Thus EQ will always fail. Unfortunately
+     calling equal is no good either as this doesn't take into account
+     things attached to the specifier - for instance strings on
+     extents. --andyp */
   if (!EQ (newval, *location))
     {
       Lisp_Object oldval = *location;