Single-letter second-level domains

Single-letter second-level domains

Single-letter second-level domains are domain names in which the second-level domain consists of only one letter, such as Such domains are rare, due to the fact that on December 1 1993, The Internet Assigned Numbers Authority explicitly reserved all single-letter and single-digit second-level domain names in the top-level domains .com, .net, and .org. This was done in case the registries for these domains became overloaded. In December 2005, ICANN considered auctioning off their domains.

Active single-letter domains

However, the few such domains that were already assigned were not recalled; They were grand-fathered in and therefore were not affected by the restrictions that have existed since.

Of the above addresses, as of May 2008 only two, and, actually host a Web site directly in the single-letter domain in question. Three others redirect to sites in different domains, and one, does not appear to be active for Web use.

Two-letter domain names

Two-letter domain names are also restricted to prevent confusion with country-codes. However, this restriction was enacted long after domain names became popular, so there are many existing registrations in the old top-level domains, though they are prevented in most of the new ones such as .info. Several notable examples are,,,, and

In some new TLDs, special exceptions were made to permit two-letter domains for particular purposes; for instance, in the .aero domain the domains are reserved for airlines identified by their two-letter codes, such as for American Airlines.


With the 2005 announcement that registration of the remaining single-letter names might become available, some companies have begun jockeying into position to claim them by claiming to own trademark rights over single letters used in such a context. U Magazine, a college oriented publication, has gone so far as to re-brand its Web site as "", with a ™ sign, in online logos and captions [] even though it is not actually at that address; and they have sent a [ letter] to ICANN attempting to jump the queue for registration of this name.

In other cases, domain registrations for single letters have been granted and then revoked. One case is with that was granted to an individual in November 1999 and then revoked in January 2000.Fact|date=March 2008


External links

* [ ICANN - Reserved domain names]
* [ MSN]
* [ VB - list of large companies using two letter domains]

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