+ * emacs-lisp/eldoc.el (eldoc-documentation-function): Describe how
+ major modes should use `add-function' to alter value of the variable.
+
+ * hexl.el (hexl-mode): Set `eldoc-documentation-function' using
+ `add-function' so the default value is always used.
+ * ielm.el (inferior-emacs-lisp-mode): Set
+ `eldoc-documentation-function' using `add-function' so the default
+ value is always used.
+ * progmodes/cfengine.el (cfengine3-mode): Set
+ `eldoc-documentation-function' using `add-function' so the default
+ value is always used.
+ * progmodes/elisp-mode (emacs-lisp-mode): Set
+ `eldoc-documentation-function' using `add-function' so the default
+ value is always used.
+ * progmodes/octave.el (octave-mode): Set
+ `eldoc-documentation-function' using `add-function' so the default
+ value is always used.
+ * progmodes/python.el (python-mode): Set
+ `eldoc-documentation-function' using `add-function' so the default
+ value is always used.
+ * simple.el (read--expression): Set `eldoc-documentation-function'
+ using `add-function' so the default value is always used.
+