Rule Name	Argument	Rule Description
required		Some input is required in the field.
maxlength	$length	The input can be at most $length characters.
minlength	$length	The input must be at least $length characters.
rangelength	$min,$max	The input must be between $min and $max characters (inclusive).
regex	$rx	The input must match the regular expression $rx.
email		The input must be a likely syntactically valid e-mail address.*
emailorblank		The input must be blank or satisfy the email rule.
lettersonly		The input must contain only alphabetic characters.
alphanumeric		The input must contain only letters and numbers.
numeric		The input must contain a valid positive or negative integer or decimal number.
nopunctuation		The input must not contain any of these characters: ( ) . / * ^ ? # ! @ $ % + = , " ' > < ~ [ ] { }.
nonzero		The input must not begin with zero.
uploadedfile		The element must contain a successfully uploaded file.
maxfilesize	$size	The uploaded file must be no more than $size bytes.
mimetype	$mime	The uploaded file must have a MIME type of $mime. If $mime is an array of MIME types, the uploaded file must have a MIME type equal to one of the elements in $mime.
filename	$file_rx	The uploaded file must have a filename that matches the regular expression $file_rx.