Library /sys$common/syshlp/lse$menu.hlb DECW menus mnemonic  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  This is the mnemonic associated with the selected label.

  This character will be used by the windowing system to keyboard
  traversal of the menus.  The charaacter must be unique within the
  Menu.  To find which characters have been consumed, pull down the
  Menu in question and look for the "_"s.  Those letters have been
  consumed.