Revalidate exports some common validations for your convenience. If you need something more complex, then you'll need to create your own validators with createValidator.
createValidator
isRequired
isRequiredIf
isAlphabetic
isAlphaNumeric
isNumeric
hasLengthBetween
hasLengthGreaterThan
hasLengthLessThan
isOneOf
matchesPattern
matchesField