What is sTLD?
Also known as: Sponsored Top-Level Domain
A sponsored top-level domain (sTLD) is a TLD with a sponsoring organisation that enforces eligibility rules limiting registration to a defined community, such as .museum or .gov.
A sponsored top-level domain (sTLD) is a category of generic top-level domain (gTLD) for which a designated sponsoring organisation sets and enforces registration policies. The sponsor represents a specific community, for example cultural, professional, or governmental, and restricts domain registrations to members or entities within that community. The sponsoring organisation defines eligibility criteria, maintains a charter, and is accountable to ICANN for compliance.
The sTLD model was created during the 2000 and 2004 rounds of new TLDs to serve clearly bounded user groups. Unlike unsponsored gTLDs such as .com or .org, where any party may register without community-based restriction, sTLDs require applicants to demonstrate membership in the target group. For example, .museum is sponsored by the Museum Domain Management Association (MuseDoma), and only verified museums and related institutions can register. Similarly, .gov in the United States is a sTLD for U.S. federal, state, and local government entities, sponsored by the General Services Administration (GSA). Other historical sTLDs include .aero for aviation, .coop for cooperatives, and .pro for licensed professionals.
ICANN later adopted a broader gTLD program starting in 2012, which diluted the distinction between sponsored and unsponsored TLDs. Most new domains became unrestricted gTLDs, though some carry community-based restrictions. The term sTLD remains in use as a formal label from the earlier regime, distinguishing TLDs with a narrow, sponsor-enforced eligibility model from those open to general registration.
Key facts
- A sponsoring organisation defines and enforces eligibility for each sTLD.
- ICANN approved sTLDs in the 2000 and 2004 application rounds.
- Only verified members of the sponsor's community may register sTLD domains.
- Examples include .museum, .gov, .aero, .coop, and .pro.
- The 2012 gTLD expansion reduced new sTLD creation, but existing sTLDs remain operational.
- Sponsors are contractually obligated to ICANN to uphold the TLD's charter.
How it works in practice
Related terms
References
More in Domains
Auth Code
A unique, per-domain secret code that the losing (current) registrar must provide so the gaining (new) registrar can authorize a domain transfer.
ccTLD
A ccTLD is a two-letter top-level domain assigned to a country or territory based on the ISO 3166-1 alpha-2 code, such as .us for the United States or .jp for Japan.
Domain Lock
A registrar-level status that prevents unauthorized domain transfers, modifications, or deletions until the registrant explicitly removes the lock.
Domain Privacy
An optional service that replaces the domain registrant's personal contact information in WHOIS records with the registrar's proxy details to shield the owner from spam and unwanted disclosure.
EPP
EPP (Extensible Provisioning Protocol) is an XML-based application protocol used by domain name registries and registrars to provision domain names, manage contacts, and transfer registrations.
Grace Period
The grace period is a window after a domain expires during which the registrant can renew at the standard renewal fee, without incurring additional redemption costs.
IDN
An Internationalized Domain Name (IDN) is a domain name that includes characters outside the ASCII set, encoded as Punycode for compatibility with the DNS.
Punycode
Punycode is a method defined in RFC 3492 for converting Unicode strings into ASCII labels, enabling Internationalized Domain Names (IDNs) to be used in the DNS.
RDAP
RDAP (Registration Data Access Protocol) is a modern RESTful protocol for querying domain name and IP address registration data, replacing the older WHOIS protocol with structured JSON responses and role-based access controls.
Registrant
The registrant is the legal holder of a domain name, listed as the owner in the registry database and responsible for the domain's renewal and administration.