| ISO 639-3 Reference Names | art-289 |
| No linguistic content | |
| ISO 639-3 | art-001 | zxx |
| ISO 639-2/T | art-002 | zxx |
| ISO 639-2/B | art-003 | zxx |
| ISO 639-3 Print Names | art-290 | No linguistic content |
| ISO 639-3 Print Names | art-290 | Not applicable |
| ISO 639-3 Inverted Names | art-291 | No linguistic content |
| ISO 639-3 Inverted Names | art-291 | Not applicable |