The CITADEL Top-Level Domain (TLD) does not currently exist in the Internet’s Domain Name System. In general, a TLD is the last segment of a domain name, which follows immediately after the “dot” symbol. TLDs fall into two categories: generic TLDs (such as .com, .net, .edu, and .gov) and country code TLDs (such as .us, .ca, .fr, and .jp).
The Internet Corporation for Assigned Names and Numbers (ICANN), a nonprofit organization, oversees the allocation and assignment of TLDs. According to ICANN’s list of TLDs, there is no current TLD named CITADEL. However, it is theoretically possible for an application for .CITADEL to be made in a future round of TLD expansion but there is no guarantee ICANN would approve the application. This information is found on the official ICANN website (https://www.icann.org/resources/pages/tlds-2012-02-25-en).
Here are some examples of TLDs: .com (for commercial), .org (for organizations), .gov (for government agencies), .edu (for educational institutions), .net (for network organizations), .int (for international organizations). There are also more specific or newer ones such as .pizza, .museum, .bike, .google, and so on.
Historically, the earliest TLDs were created in the 1980s, as documented by the Internet Assigned Numbers Authority (IANA). At present, there are more than a thousand TLDs available for registration via authorized registries, according to data from IANA (https://data.iana.org/TLD/tlds-alpha-by-domain.txt).
In recent years, ICANN has significantly expanded the TLD program with the introduction of new generic TLDs (gTLD). Companies, entrepreneurs, and organizations can apply for these TLDs. Google, for example, secured .google (https://gtldresult.icann.org/application-result/applicationstatus/viewstatus), and Barclays managed to get .barclays and .barclaycard (https://gtldresult.icann.org/application-result/applicationstatus/viewstatus). A potential application for .CITADEL could come from Citadel LLC, a well-known financial institution, or Citadel Outlets, a famous land-mark in Los Angeles. But of course, the ultimate authority to approve or reject an application remains with ICANN.
Furthermore, creating a unique TLD is not an inexpensive or simple task. The application fee is $185,000, not to mention other costs (economy evaluation, legal, consulting, technical implementation, and ongoing ICANN fees) that might exceed $1 million. The process also takes at least 9-20 months. Plus, it highly requires expertise in DNS technology and involve going through a rigorous selection process, as explained on the ICANN official site (https://newgtlds.icann.org/en/applicants/global-support/faqs/faqs-en).
To summarize, the TLD “CITADEL” does not currently exist, and such a TLD could only be established through a potentially complicated and expensive application process overseen by ICANN.
