This code system https://fhir.nhs.uk/CodeSystem/Ambulance-GenderIdentity defines the following codes:
| Code | Display |
| 01 | Male (including trans man) | |
| 02 | Female (including trans woman) | |
| 03 | Non-binary | |
| 04 | Other (not listed) | |
| X | Not Known (not recorded) | |
| Z | Not Stated (person asked but declined to provide a response) | |
