DSTI/ICCP/TISP(2004)2/FINAL 

TOP LEVEL DOMAIN NAME GROWTH IN OECD COUNTRIES 

Introducing Top Level Domain Names 

The Domain Name System (DNS) helps users navigate the Internet. Every device connected to the 

Internet has a unique address called its  IP address  (Internet Protocol address). Because IP addresses 

(which are strings of numbers) are hard to remember, the DNS allows a string of letters or a combination 

string of letters and numbers (the  domain name ) to be substituted. Whereas numeric IP addresses 

(

e.g.

 192.11.0.54) generally contain no signification to users, domain names may contain a meaning or 

signify a relationship with a registrant (

e.g.

 oecd.org). It is this feature of domain names that can give them 

a value, in the domain name market, over and above their functional utility.  

Domain names are composed under a hierarchical structure. This hierarchical structure of the DNS is 

supported by the dot ( . ). A sequence of letters which is called the label, divided by the dot, makes up one 

complete domain name. The highest hierarchical level of the DNS is called the top level domain (TLD) 

which is the last right label of the domain names (

e.g.

.org 

 in  oecd.org  or  

.jp

  in  sony.co.jp ). The 

hierarchy of the DNS descends in the order from right to left. The label to the left of the TLD is called the 

second level top level domain (

e.g.

  oecd  in  oecd.org  or  .co  in  sony.co.jp ).  

The TLDs can be generally categorised into two categories. One is the country code top level domain 

(ccTLD) which is designated to countries or regions and is represented by a two letter label based on the 

ISO 3166 1 standard (

e.g.

.jp

  for Japan,  

.au

  for Australia and  

.at

  for Austria). In March 2004, there 

were 243 ccTLDs in existence. In contrast, generic top level domains (gTLD) have traditionally not been 

related to geography but to generic forms of use (

e.g.

.com

 for commercial use or 

.int

 for international 

organisations). 

There are two types of gTLDs: sponsored TLDs (sTLDs) and unsponsored TLDs (uTLDs). The 

uTLDs are managed under general gTLDs policies established by the Internet Corporation for Assigned 

Names and Numbers (ICANN). In contrast, sTLDs are managed by a sponsor organisation which 

establishes policies and practices for the management of that sTLD.  Some sTLDs are reserved for the use 

of a particular community. This group of stakeholders are sometimes referred to as the Sponsored TLD 

Community. The domain name 

.museum

, for example, is operated by the Museum Domain Management 

Association (MuseDoma), a not for profit trade organisation established by the International Council for 

Museums (ICOM). This sTLD is exclusively for the museum community and only genuine museums, 

museums associations and museum professionals can register a second level domain name under 

.museum

.    

As of March 2004 there were 14 gTLDs and one TLD reserved for Internet infrastructure purposes 

(

Table 1). 

Among the `original gTLDs',

first created in the 1980s,

 .com

,

 .net 

and

 .org

 are uTLDs 

while 

.edu

, 

.gov

,

 .int 

and 

.mil

 are sTLDs. Among the `new gTLDs', approved by ICANN in November 

2000, 

.biz

, 

.info

,

 .name 

and

 .pro

 are uTLDs while

 .aero

, 

.coop 

and

 .museum

 are sTLDs. 

Registration under sTLDs is restricted to their respective communities. For the main part this does not 

relate to location but to other eligibility requirements. The domain 

.edu

 is for educational institutions that 

are accredited by an agency on the United States Department of Education's list of Nationally Recognized 

6