Using higher-level names in place of device and file names.
    (Also see Physical_devices)

  ASSIGN            Equates a logical name to an equivalence string.
  CREATE/NAME_TABLE Creates a logical name table.
  DEASSIGN          Deletes a logical name.
  DEFINE            Equates a logical name to an equivalence string.
  SHOW LOGICAL      Displays logical names and their equivalencies.
  SHOW TRANSLATION  Displays a logical name and its first equivalence.

  Type ? to display the list of HINTS.
  Type LOGICAL_NAMES to redisplay this particular hint.
  Press the RETURN key before typing a command or topic name.