[:cntrl:] all control characters\n\
[:digit:] all digits\n\
[:graph:] all printable characters, not including space\n\
- [:lower:] all lowercase letters\n\
+ [:lower:] all lower case letters\n\
[:print:] all printable characters, including space\n\
[:punct:] all punctuation characters\n\
[:space:] all horizontal or vertical whitespace\n\
- [:upper:] all uppercase letters\n\
+ [:upper:] all upper case letters\n\
[:xdigit:] all hexadecimal digits\n\
[=CHAR=] all characters which are equivalent to CHAR\n\
");