>     Common Lisp also uses the term "graphic character" in the way that you
>     and BSD use "printable character":
>
> And unfortunately so does Unicode.

According to Wikipedia
(https://en.wikipedia.org/wiki/Graphic_character#Spacing_and_non-spacing_characters):

"In Unicode, Graphic characters are those with General Category Letter,
Mark, Number, Punctuation, Symbol or Zs=space. Other code points
(General categories Control, Zl=line separator, Zp=paragraph separator)
are Format, Control, Private Use, Surrogate, Noncharacter or Reserved
(unassigned)."

Is that right?

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.

Curiously, the Zl and Zp categories contain just one character each.