The top-level domain (TLD) .NAB seems to be nonexistent in the current domain system. Top-level domains are the letters found at the end of an internet address, such as .com, .net, or .org. These are the highest level of domain names in the root zone of the Domain Name System of the Internet as per the Internet Corporation for Assigned Names and Numbers (ICANN). According to all data, there is no record or registration for a .NAB top-level domain. ICANN, a non-profit responsible for coordinating the maintenance and methods of the namespaces and numerical spaces of the internet, dictates what new TLDs can be created.
Currently, ICANN recognizes several types of TLDs such as generic TLDs (gTLDs like .com, .org), country-code TLDs (ccTLDs like .us, .uk), infrastructure top-level domain (.arpa), and sponsored TLDs (sTLDs like .gov, .edu). The list of all top-level domains is maintained by the Internet Assigned Numbers Authority (IANA), which is a part of ICANN. As of now, .NAB is not listed as a registered or proposed TLD on the IANA root zone database.
In ICANN’s new gTLD Program, organizations can apply for new gTLDs, and if approved, the new TLDs are added to the recognized DNS system. An application for the .NAB TLD may possibly be made in the future (by National Australia Bank, as “NAB” is its acronym, for example) but as of current dates, .NAB does not exist in the system.
Nonetheless, while there is no current information about a .NAB TLD, it’s worth noting that the landscape of TLDs is ever-changing and growing. In addition to the traditional TLDs, ICANN has allowed the creation of numerous new TLDs, like .biz, .info, .museum and so on. Some companies even have their brand names as TLDs (.google, .amazon).
To reiterate, according to the current list of TLDs from authoritative sources like ICANN or the IANA root zone database, there is no .NAB TLD. Whether or not it will exist in the future is not known.
Sources:
1. ICANN.org : An introduction to top-level domains (TLDs)
2. IANA.org : Root zone database
3. ICANN.org : New gTLD Program
