underline are historical relics from archaic ASCII (the 1963
version), which had these graphics in those character positions
rather than the modern punctuation characters.

The `swung dash' or `approximation' sign is not quite the same
as tilde in typeset material
but the ASCII tilde serves for both (compare {angle
brackets}).

Some other common usages cause odd overlaps. The `#',
`$', `>', and `&' characters, for example, are all
pronounced "hex" in different communities because various
assemblers use them as a prefix tag for hexadecimal constants (in
particular, `#' in many assembler-programming cultures,
`$' in the 6502 world, `>' at Texas Instruments, and
`&' on the BBC Micro, Sinclair, and some Z80 machines). See
also {splat}.

The inability of ASCII text to correctly represent any of the
world's other major languages makes the designers' choice of 7 bits
look more and more like a serious {misfeature} as the use of
international networks continues to increase (see {software
rot}). Hardware and software from the U.S. still tends to embody
the assumption that ASCII is the universal character set; this is a
a major irritant to people who want to use a character set suited
to their own languages. Perversely, though, efforts to solve this
problem by proliferating `national' character sets produce an
evolutionary pressure to use a *smaller* subset common to all
those in use.