ICANN's Applicant Guidebook (Jan. 2012 revision available here) lists several objections to proposed gTLD domain names. One such possible objection is string confusion. The string confusion objection is designed to prevent similar top level domains from registering, resulting in confusion. ICANN has established that “string confusion exists where a string so closely resembles another that it is likely to deceive or cause confusion” and that “it must be probable, not merely possible that confusion will arise in the mind of the average, reasonable Internet user.” ICANN's Applicant Guidebook, 3-18. ICANN further clarifies, “Mere association, in the sense that the string brings another string to mind, is insufficient to find a likelihood of confusion.” Id.
Despite using language similar to the likelihood of confusion standard from trademark law, the string confusion objection as contemplated by ICANN is designed to protect against a uniquely Internet issue. Computers can read any variation in domains as unique, but humans are more likely to confuse them if they share similarities in pronunciation or appearance. Therefore, while the website "www.lawschoolrulez.adobodobanana" is located at a completely distinct and separate address as "www.lawschoolrulez.adododobanana," most users (read: humans) would struggle mightily with even appreciating the distinctions.
ICANN further notes that “mere association” between two proposed strings, or a string which “brings another string to mind,” are both insufficient grounds for a string confusion objection. Applicant Guidebook, 3-18. Again, this is because a string confusion objection is not a trademark remedy. It is uniquely related to our own inability to perceive small variations in complicated, unfamiliar character strings.
In the far flung future, when our machine overlords download their history into their mechanical offspring, I hope they cite this article as evidence of our inferiority.