The following table list all valid values that can be used in a character class expression [:class:]:

alnumAny alpha-numeric character.
alphaAny alphabetic character.
blankAny whitespace character that is not a line separator.
cntrlAny control character.
dAny decimal digit
digitAny decimal digit.
graphAny graphical character.
lAny lower case character.
lowerAny lower case character.
printAny printable character.
punctAny punctuation character.
sAny whitespace character.
spaceAny whitespace character.
unicodeAny extended character whose code point is above 255 in value.
uAny upper case character.
upperAny upper case character.
wAny word character (alphanumeric characters plus the underscore).
wordAny word character (alphanumeric characters plus the underscore).
xdigitAny hexadecimal digit character.
EXAMPLE[[:upper:]] will match any upper case character.
^[[:lower:]].* will match any string that starts with a lower case character.
NOTEPerl regular expressions syntax is used in all products.