.ac
| Introduced | 1997 |
|---|---|
| TLD type | Country code top-level domain |
| Status | Active |
| Registry | Ascension Island Network Information Centre (run by Internet Computer Bureau) |
| Sponsor | Cable and Wireless (Ascension Island) |
| Intended use | Entities connected with  Ascension Island |
| Actual use | Various uses, sometimes connected to education and academia; a few sites actually on Ascension Island |
| Registration restrictions | 2nd-level registrant must have professional or academic qualification (apparently not actually enforced); 3rd level registrant must be resident on Ascension Island |
| Structure | Registrations are taken directly at the second level or at third level beneath various 2nd-level labels |
| Documents | Terms & Conditions; Rules |
| Dispute policies | Dispute Resolution Policy |
| DNSSEC | yes |
| Registry website | NIC.AC |
.ac is the Internet country code top-level domain (ccTLD) for Ascension Island. It is administered by NIC.AC, a subsidiary of the Internet Computer Bureau based in the United Kingdom.
Registration for this domain is open to anyone. The registry accepts registrations of internationalized domain names.[1]
.ac is marketed by some domain-brokers as a domain for the city of Aachen in Germany, using the analogy to the automotive license plate designation ("AC") for the city.
Use as an abbreviation for "academic"
Due to its similarity to the .ac (“academic”) second-level domain that exists under some country code top-level domains, some educational institutions also register under the .ac top-level domain:
- Ishik University (http://ishik.ac/)
- The University of Kurdistan - Hawler (http://ukh.ac/)
- Ralston College in Savannah, Georgia, USA (http://www.ralston.ac)
- The Faith Mission Bible College in Edinburgh, Scotland (http://www.fmbc.ac)
- The Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok, Thailand (http://www.tropmedres.ac/)
- INFORM (Information Network Focus on Religious Movements), based at the London School of Economics (http://inform.ac/)
- Newcastle University (http://www.unc.ac/), an online institution unconnected with Newcastle University in the United Kingdom and the University of Newcastle, Australia
Second-level subdomains
There are five second-level domains:
- com.ac: Commercial Entities
- net.ac: Network Service Providers
- gov.ac: Government
- org.ac: Non-commercial Organizations
- mil.ac: Military