func BidiRule() Option {
	return func(o *options) { o.bidirule = bidirule.ValidString }
}

// ValidateForRegistration sets validation options to verify that a given IDN is
// properly formatted for registration as defined by Section 4 of RFC 5891.
func ValidateForRegistration() Option {
	return func(o *options) {
		o.mapping = validateRegistration
		StrictDomainName(true)(o)
		ValidateLabels(true)(o)

func BidiRule() Option {
	return func(o *options) { o.bidirule = bidirule.ValidString }
}

// ValidateForRegistration sets validation options to verify that a given IDN is
// properly formatted for registration as defined by Section 4 of RFC 5891.
func ValidateForRegistration() Option {
	return func(o *options) {
		o.mapping = validateRegistration
		StrictDomainName(true)(o)
		ValidateLabels(true)(o)