In 2010, ICANN’s Security and Stability Advisory Committee (SSAC) published SAC045, a report calling attention to particular problems that may arise should a new gTLD applicant use a string that has been seen with measurable (and meaningful) frequency in queries for resolution by the root system. The queries to which they referred involved invalid top-level domain (TLD) queries (i.e., non-delegated strings) at the root level of the domain name system (DNS), queries which elicit responses commonly referred to as Name Error, or NXDomain, responses from root name servers.
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