(custom-add-parent-links): New arg DOC-INITIAL-STRING.

Defaults for INITIAL-STRING and DOC-INITIAL-STRING do not include `parent'.
(custom-group-value-create): Pass two args to custom-add-parent-links.

lisp/cus-edit.el

@@ -2313,7 +2313,8 @@ Insert PREFIX first if non-nil."
 	       (insert ", "))))
       (widget-put widget :buttons buttons))))
 
-(defun custom-add-parent-links (widget &optional initial-string)
+(defun custom-add-parent-links (widget &optional initial-string
+				       doc-initial-string)
   "Add \"Parent groups: ...\" to WIDGET if the group has parents.
 The value is non-nil if any parents were found.
 If INITIAL-STRING is non-nil, use that rather than \"Parent groups:\"."
@@ -2322,7 +2323,7 @@ If INITIAL-STRING is non-nil, use that rather than \"Parent groups:\"."
 	(buttons (widget-get widget :buttons))
 	(start (point))
 	(parents nil))
-    (insert (or initial-string "Parent groups:"))
+    (insert (or initial-string "Groups:"))
     (mapatoms (lambda (symbol)
 		(when (member (list name type) (get symbol 'custom-group))
 		  (insert " ")
@@ -2343,7 +2344,7 @@ If INITIAL-STRING is non-nil, use that rather than \"Parent groups:\"."
            (when links
              (let ((pt (point))
                    (left-margin (+ left-margin 2)))
-             (insert "\nParent documentation: ")
+	     (insert "\n" (or doc-initial-string "Group documentation:") " ")
              (while links
                (push (widget-create-child-and-convert
 		      widget (car links)
@@ -3944,7 +3945,8 @@ If GROUPS-ONLY non-nil, return only those members that are groups."
 		    ;;; was made to display a group.
 	       (when (eq level 1)
 		 (if (custom-add-parent-links widget
-					      "Parent groups:")
+					      "Parent groups:"
+					      "Parent group documentation:")
 		     (insert "\n"))))
 	   ;; Create level indicator.
 	   (insert-char ?\  (* custom-buffer-indent (1- level)))