print-charset-text-property

print-charset-text-property is a variable defined in `C source code'.
Its value is

default

Documentation:
A flag to control printing of `charset' text property on printing a string.
The value must be nil, t, or `default'.

If the value is nil, don't print the text property `charset'.

If the value is t, always print the text property `charset'.

If the value is `default', print the text property `charset' only when
the value is different from what is guessed in the current charset
priorities.