-'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'.