With more and more domain name registrars offering some sort of pre-registration or pre-reservation service for new top level domain names, ICANN has published a word of caution.

Cyrus Namazi, Vice President of DNS Industry Engagement for ICANN, published a blog post today titled “Pre-Reserve a Domain Name, or Not? ICANN Answers the Question.”

As responsible Registrars are advising, successful pre-registration of a domain cannot be guaranteed. ICANN seconds that advice, cautioning that registrants should be wary of anyone who claims to be able to guarantee a domain registration on a new gTLD. There are several situations that can impact the availability of a domain name and some domain names may never be available for purchase.

Namazi points out that competition between registrars for a single domain, domains claimed in sunrise, reserved domains, premium domains, and name collision domains make it impossible to guarantee. He also notes that some TLDs may not even end up being delegated.

I haven’t personally seen any offers that guarantee you’ll get a domain you pre-register, although the language and disclaimers are probably unclear to the average internet user.