+matches at least one character from the set below:
[:alnum:]an alphanumeric character [a-zA-Z0-9]
.the literal . (4610 / 568 / 2E16)
_the literal _ (9510 / 1378 / 5F16)
+the literal + (4310 / 538 / 2B16)
~the literal ~ (12610 / 1768 / 7E16)
-the literal - (4510 / 558 / 2D16)