Here is a list of predefined validators. You cannot use these names for your custom validators. || **name** || **arguments** || **task** || || email || || Check if value is valid email.|| || notblank || || Check if value is not blank.|| || notnull || || Check if value is not null.|| || country || || Check if valid is valid country code.|| || ip || || Checks if value is valid IP (internet protocol) address.|| || htmlcolor || || Checks if value is valid html color.|| || nospace || || Check if value has no space chars. || || range || [min,max] || Checks if value is in range specified by arguments.|| || unique || || Checks if value is unique in its database table. || || regexp || [expression] || Check if valie matches a given regexp. ||