.us

.us

Introduced	1985
TLD type	Country code top-level domain
Status	Active
Registry	Neustar
Sponsor	United States Department of Commerce
Intended use	Entities connected with  United States
Actual use	American business use of its own country code top level domain (ccTLD) is fast growing in popularity
Registration restrictions	U.S. nexus requirement can be enforced by challenge, but seldom is
Structure	Originally registrations were within complex, 3rd or 4th level hierarchy, but currently direct second-level registrations are allowed; kids.us permits 3rd-level registrations for child-friendly sites
Documents	RFC 1480; USDoC agreements with Neustar
Dispute policies	usTLD Dispute Resolution Policy (usDRP)
Website	nic.us

.us is the Internet country code top-level domain (ccTLD) for the United States, established in 1985. Registrants of .us domains must be United States citizens, residents, or organizations, or a foreign entity with a presence in the United States. Most registrants in the country have registered for .com, .net, .org and other gTLDs, rather than .us, which has traditionally primarily been used by many state and local governments (although any entity had the option of registering a .us domain). In particular, the domains .gov and .mil have been reserved for U.S. government and military usage, respectively.

The original administrator of .us was Jon Postel of the Information Sciences Institute at the University of Southern California. He administered .us under a sub-contract USC/ISI had from SRI International (who held the .us and the Generic top-level domains contract with the United States Department of Defense) and later Network Solutions (who held the .us and the Generic top-level domains contract with the National Science Foundation). Registrants could only register third-level domains or higher in a geographic and organizational hierarchy. The vast majority of the geographic sub-domains in .us were delegated to various private entities and .us registrants register with the delegated administrator for the level they wish to register in, not directly with the .us administrator.

In April 2002, second-level domains under .us became available for registration. The .us domain is currently administered by NeuStar Inc. under a United States Department of Commerce contract.

Second-level domains for states

Each U.S. state, federal territory and the District of Columbia has a reserved two-letter second-level domain based on the International Organization for Standardization Standard ISO 3166-2:US for the United States, for instance, .ny.us for New York, and .va.us for Virginia. However, some state administrations prefer usage of their .gov domains or others; e.g., California is located at www.ca.gov, rather than www.ca.us.

Additionally, the territories of the US have their own country code top-level domain — .as for American Samoa, .gu for Guam, .mp for Northern Mariana Islands, .pr for Puerto Rico, and .vi for United States Virgin Islands — which operate alongside, or in preference to, their .us subdomains (.as.us, .gu.us, .mp.us, .pr.us, and .vi.us respectively).

Other administered second-level domains

• .dni.us: distributed national institutes
• .fed.us: federal government agencies (an alternative to .gov)
• .isa.us: interstate agency (only used for the Interstate Mining Compact Commission, imcc.isa.us)
• .kids.us: content "suitable for children under 13"
• .nsn.us: Native sovereign nations (federally recognized Native American tribes)

Locality-based namespaces

The general format is "<organization-name>.<locality>.<state>.us", where <state> is a state's two-letter postal abbreviation.

Three values of <organization-name> have specific meanings:

• ci: city government agencies (ci.<locality>.<state>.us)
  • Examples: http://ci.boston.ma.us/ or http://ci.sacramento.ca.us/
• town: town government agencies (town.<locality>.<state>.us)
  • Examples: http://town.florence.az.us/ or http://town.windermere.fl.us/
• vil: village government agencies (vil.<locality>.<state>.us)
  • Examples: http://vil.stockbridge.mi.us/ or http://vil.wrightstown.wi.us/
• co: county government agencies (co.<locality>.<state>.us)
  • Examples: http://co.adams.id.us/ or http://co.greene.oh.us/

Ordinarily, a <locality> is a city, county, parish, or township. Some other names may replace the <locality>:

• state: state government agencies (<organization-name>.state.<state>.us)
  • Examples: http://www.state.ak.us/ or http://www.state.mn.us/
• dst: government agencies in administrative districts (<organization-name>.dst.<state>.us)
• cog: councils of government (federations of cities or counties) (<organization-name>.cog.<state>.us)
• k12: public elementary or secondary schools (<school-name>.k12.<state>.us)
• pvt.k12: private elementary or secondary schools (<school-name>.pvt.k12.<state>.us)
• cc: community colleges (<school-name>.cc.<state>.us)
• tec: technical and vocational schools (<school-name>.tec.<state>.us)
• lib: public libraries (<library-name>.lib.<state>.us)
• mus: museums (<museum-name>.mus.<state>.us)
• gen: general independent entities (groups not fitting into the above categories) (<organization-name>.gen.<state>.us)

As noted above, registration of a subdomain in this space may depend on the cooperation of a private delegate. Many mainstream registration companies do not offer domains in this space, which may account for the low utilization rate.

Restrictions on use of .us domains

Under .US Nexus Requirements .US domains may be registered only by the following qualified entities:

• Any United States citizen or resident,
• Any United States entity, such as organizations or corporations,
• Any foreign entity or organization with a bona fide presence in the United States

To ensure that these requirements are met, NeuStar frequently conducts "spot checks" on registrant information.

To prevent anonymous registrations that do not meet these requirements, the National Telecommunications and Information Administration has ruled that registrants of .us domains may not secure private domain name registration [1].

Registrants are required to provide complete contact information without omissions. [2]

Domain names corresponding to 5-digit or 9-digit US postal codes or telephone numbers are reserved; a project is underway at zipcode.us to provide locality-specific information under a full set of 5-digit postal-code .us subdomains.

See also

• Country Code top-level domain

External links

• .us Domain Registry
• IANA .us whois information
• Management of .us Domain Name (U.S. Department of Commerce)
• usTLD Nexus Requirements - Requirements for registrants of .us domains, Portable Document Format
• Kids.us Content Policies
• RFC 1480: The US Domain (June 1993)
• locality-based namespaces