As far as I'm concerned "printable characters" are the set of characters that occupies a printing position on a display. You can print a subset of (not all) printable characters by executing
:echo &isprint @,161-255
The speciications present in
vim documentation are concise. According to
:h 'isprint', characters from space (decimal value: 32) to tilde (decimal value: 126) are considered as printable characters, even they are not included in
'isprint' or excluded. This raises the following question: why is the at sign (
@) explicitly specified within the set of characters that is displayed by executing
:h 'isprint' while the other characters are represented by a range of decimal values. Does this implies something significant? Is the at sign considered as something more than a simple character?