Gender Marker (Medical / Governmental) Regex for Go

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching gender marker (medical / governmental), ported and verified for Go. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// Gender Marker (Medical / Governmental)
// ReDoS-safe | RegexVault — Identity & PII > Biometric & Physical

package validation

import "regexp"

var genderMarkerMedicalGovernmentalRe = regexp.MustCompile(`^(?:M|F|X|O|U|N|NB|MALE|FEMALE|NON-BINARY|UNKNOWN|UNSPECIFIED|PREFER_NOT_TO_SAY|INTERSEX)$`)

func ValidateGenderMarkerMedicalGovernmental(s string) bool {
    return genderMarkerMedicalGovernmentalRe.MatchString(s)
}

// Example
// fmt.Println(ValidateGenderMarkerMedicalGovernmental("M")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Biometric & Physical category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

ICAO uses M/F/X for passports. HL7 FHIR uses M/F/O/U/N codes. Government documents vary: AU allows X (non-binary), UK driving licence adds a 5-month offset for female, CA federal documents allow X. The X gender marker is now recognized in many jurisdictions.