A flag to control extra guidance given by input methods.
The value should be nil, t, `complex-only', or `default'.
The extra guidance is done by showing list of available keys in echo
area. When you use the input method in the minibuffer, the guidance
is shown at the bottom short window (split from the existing window).
If the value is t, extra guidance is always given, if the value is
nil, extra guidance is always suppressed.
If the value is `complex-only', only complex input methods such as
`chinese-py' and `japanese' give extra guidance.
If the value is `default', complex input methods always give extra
guidance, but simple input methods give it only when you are not in
the minibuffer. See also the variable `input-method-highlight-flag'.