Good news: The consoles under Windows, LINUX and MacOS support full UNICODE.
Bad news: Most console and terminal programs do not display all available UNICODE characters properly
All consoles support the ANSI (formerly: ASCII) chracter set. Most consoles support additional character sets such as
Some modern console programs support an increasing number of UNICODE symbols, including various Asian fonts and emojies. Unsupported symbols will automatically be shown using question marks or placeholder boxes.
Consoles under Windows have only limited capabilities to input non-ANSI characters. Under Windows, foreign characters are accepted, but the EURO-symbol is not.
Hint: Consider using character entities to specify special characters which you do cannot find on your keyboard.