The WHOIS information of a domain name is a collection of a number of details which are openly accessed through specific lookup sites or a command line. The protocol that makes this possible bears the same name and you could very easily see the organization through which a domain address has been registered, the creation, expiration and last update dates in addition to the names, postal and e-mail address of the individuals listed as Registrant (owner), Administrative, Technical and Billing contacts for a specific domain address. All of this information has to be valid and up-to-date constantly; otherwise the domain address registration can be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), so you must always ensure that the WHOIS details of your domain addresses are accurate. Updating the WHOIS for a variety of country-code TLDs is limited, so any time you register a new domain address, you ought to double-check the info you're submitting.