> The general category Zs ("Separator, Space") contains 17 characters:
> <https://www.fileformat.info/info/unicode/category/Zs/list.htm>. So it's
> not just the ASCII space character.

But the only ASCII character in that category is space. Tab, newline,
etc. are not included. So testing for space but no other whitespace
characters in `ascii-graphic?` would match Unicode and Common Lisp. As
best I can tell it would also match the ASCII standard (though that PDF
is very hard to scan for unambiguous character class assignments, and
there's conflicting information around the net).