text: However, some of these are effectively unused. In particular, the ccTLDs for the Norwegian dependency Bouvet Island (bv) and the designation Svalbard and Jan Mayen (sj) do exist in DNS, but no subdomains have been assigned, and it is Norid policy to not assign any at present. Two French territories—bl (Saint Barthélemy) and mf (Saint Martin)— await local assignment by France's government.
  The code eh, although eligible as ccTLD for Western Sahara, has never been assigned and does not exist in DNS. Only one subdomain is still registered in gb (ISO 3166-1 for the United Kingdom), and no new registrations are being accepted for it. Sites in the United Kingdom generally useuk (see below).
  The former .um ccTLD for the U.S. Minor Outlying Islands was removed in April 2008. Under RFC 1591 rules, .um is eligible as a ccTLD on request by the relevant governmental agency and local Internet user community.
  ASCII ccTLDs not in ISO 3166-1
  Several ASCII ccTLDs are in use that are not ISO 3166-1 two-letter codes. Some of these codes were specified in older versions of the ISO list.
  uk (United Kingdom): The ISO 3166-1 code for the United Kingdom is GB.  However, the JANET network had already selected uk as a top-level identifier for its pre-existing Name Registration Scheme, and this was incorporated into the DNS root. gb was assigned with the intention of a transition, but this never occurred and the use of uk is now entrenched.