Special-use domain name
A special-use domain name is a domain name that is defined and reserved in the hierarchy of the Domain Name System of the Internet for special purposes. The designation of a reserved special-use domain is authorized by the Internet Engineering Task Force and executed, maintained, and published by the Internet Assigned Numbers Authority.
Reserved domain names
The following list comprises the domain names list by IANA in the category of special-use domain names.| Domain | Purpose | Authority document |
| .alt | preventing name collisions with DNS | |
| 6tisch.arpa | IETF 6TiSCH working group | |
| 10.in-addr.arpa | private network reverse mapping | |
| 16.172.in-addr.arpa | private network reverse mapping | |
| 17.172.in-addr.arpa | private network reverse mapping | |
| 18.172.in-addr.arpa | private network reverse mapping | |
| 19.172.in-addr.arpa | private network reverse mapping | |
| 20.172.in-addr.arpa | private network reverse mapping | |
| 21.172.in-addr.arpa | private network reverse mapping | |
| 22.172.in-addr.arpa | private network reverse mapping | |
| 23.172.in-addr.arpa | private network reverse mapping | |
| 24.172.in-addr.arpa | private network reverse mapping | |
| 25.172.in-addr.arpa | private network reverse mapping | |
| 26.172.in-addr.arpa | private network reverse mapping | |
| 27.172.in-addr.arpa | private network reverse mapping | |
| 28.172.in-addr.arpa | private network reverse mapping | |
| 29.172.in-addr.arpa | private network reverse mapping | |
| 30.172.in-addr.arpa | private network reverse mapping | |
| 31.172.in-addr.arpa | private network reverse mapping | |
| 168.192.in-addr.arpa | private network reverse mapping | |
| 170.0.0.192.in-addr.arpa | NAT64 prefix discovery | |
| 171.0.0.192.in-addr.arpa | NAT64 prefix discovery | |
| ipv4only.arpa | NAT64 prefix discovery | |
| 254.169.in-addr.arpa | Use in multicast DNS | |
| 8.e.f.ip6.arpa | Use in multicast DNS | |
| 9.e.f.ip6.arpa | Use in multicast DNS | |
| a.e.f.ip6.arpa | Use in multicast DNS | |
| b.e.f.ip6.arpa | Use in multicast DNS | |
| .home.arpa | Non-unique use on residential networks | |
| .example | documentation, tutorials, etc. | RFC 6761 |
| example.com | use in documentation, tutorials, testing | RFC 6761 |
| example.net | use in documentation, tutorials, testing | RFC 6761 |
| example.org | use in documentation, tutorials, testing | RFC 6761 |
| .invalid | Avoidance of confusion and errors | RFC 6761 |
| .local | Used for Multicast DNS | RFC 6762 |
| .localhost | Reserved to avoidance of confusion and errors | RFC 6761 |
| .onion | Anonymous onion service | |
| .test | Avoidance of confusion, allowing use for documentation and network testing | RFC 6761 |