[keithwinstein]

Generally not. On the Internet, ASCII generally means ANSI_X3.4-1968, a 7-bit standard with 128 code points. (Run "man ascii" on a Unix system to see this.) There aren't any accented characters.

By contrast, there were national variants of ISO/IEC 646 (also a 7-bit character set, and essentially the internationalized version of ASCII) that included accented characters within those 128 code points. Generally these swapped out things like the at-sign (@) and the curly braces and vertical pipe character for accented vowels instead.

There were also lots of 8-bit character sets in ISO/IEC 8859 (e.g. Latin-1, or ISO/IEC 8859 part 1) that included accented characters within the "extended" set of code points 128-255.