>>> A character is "graphic" if it takes up room on the display surface: thus a
>>> letter, number, punctuation mark, symbol, combining character (none in
>>> ASCII), or any of Unicode's various space separator characters.  It is
>>> "printable" if it also leaves ink on the display surface, which excludes
>>> the last group.  (Unicode does not define "printable", but ISO C and C++
>>> do.)
>>
>> Based on BSD manual pages, isprint() is like isgraph() but also includes
>> the space character. isprint() does not include tab or newline.
>>
>
> Right.  Those move you around on the display surface as opposed to
> occupying it.

I guess the distinction is somewhat moot nowadays on video displays, and
especially in GUIs. A tab's width is still N characters' width.

The BSD graphic vs printable distinction is also swapped from your
explanation.