Variable: tmm-shortcut-style
tmm-shortcut-style is a customizable variable defined in tmm.el.gz.
Value
(downcase upcase)
Documentation
What letters to use as menu shortcuts.
Must be either one of the symbols downcase or upcase,
or else a list of the two in the order you prefer.
Source Code
;; Defined in /usr/src/emacs/lisp/tmm.el.gz
(defcustom tmm-shortcut-style '(downcase upcase)
"What letters to use as menu shortcuts.
Must be either one of the symbols `downcase' or `upcase',
or else a list of the two in the order you prefer."
:type '(choice (const downcase)
(const upcase)
(repeat (choice (const downcase) (const upcase)))))