ASCII includes characters like é, à, ü, ò, ñ, etc...
Like in any programming language, ASCII (uses 1 byte to define a character) is always supported. It is Unicode (uses 2 bytes to define a character) which must be programmed within the program.
ASCII-chart:
http://www.asciitable.com/ or also see
http://www.jimprice.com/jim-asc.htm for detailed info
Unicode-charts:
http://www.unicode.org/charts/