The country code top level domain (ccTLD) .AD is assigned to Andorra. The TLD is restricted for use. There are requirements for a connection to the country itself and is available for use only by Andorra citizens and trademark holders.
There are no officially configured second-level subdomains but some common ones do appear like .gov.AD.
Because .AD looks like "advertisement", it is sometimes used as a domain nethack.
The .AD ccTLD has been activated by Andorra Telecom, the sponsor and registrar. The ccTLD has been available since 1995. The Internet and the ccTLD is available and not very popular both inside and outside the country.
Iron Noder 2017