FileNames with the high bit set.

Tue Apr 12 02:46:12 AEST 1988

> Disallowing the high order bit in filenames was done in 4BSD.  I think
> the reason had something to do with printability--a desire to limit
> the filesystem namespace to ASCII codes.

"printable" != "ASCII".  ^A is ASCII (it's the SOH control character), but it's
not printable; most terminals just ignore it.  0xC4 is printable on some
terminals (e.g. DEC VT200 series, and workstations with a character in that
position in their fonts), being "capital-A-with-a-diaresis" in ISO Latin #1,
but it's not ASCII.

Limiting the filesystem namespace to ASCII codes doesn't guarantee that all
file names will be printable, and guarantees that some names that are printable
on some machines are disallowed.