A shortcut key represents a way of accessing a menu using the keyboard. Each item of a menu can have a letter underlined, indicating that it can be selected by holding down the Alt key and pressing the letter (or certain other keys). The components of subsequent sub-menus can then be selected by pressing further keys corresponding to underlined letters in the menus. The whole process of underlining the letters and responding to the keyboard is controlled by merely prefixing the letter in the menu item by an '&' (see %mn and %sm).