In addition to the country-code top-level domains (TLDs) such as .fr for France or .tv for Tuvalu that are supervised by national governments, there are 21 generic TLDs overseen by ICANN. These include the truly generic .com, .biz, or .org as well as more specialist domains such as .aero, .coop or .museum.

ICANN wants to vastly increase the number of gTLDs, a move it says will increase competition in the domain name registration market and will allow for "more innovation, choice and change."

However, critics of this plan have said that the creation of new TLDs will oblige trademark owners to risk consumer confusion or make defensive registrations of their brands in each of the new TLDs, much as they have to today in country-code TLDs and competing gTLDs such as .com and .biz.

In an attempt to defuse such criticisms, ICANN has invited Dennis Carlton, a professor of economics at the University of Chicago, to evaluate its plans. He authored both of the reports ICANN published Saturday.

The first, "Regarding ICANN's proposed mechanism for introducing new gTLDs," combines and updates preliminary reports on the new domain-name plan that Carlton wrote for ICANN in March. Of its 57 pages, 23 are devoted to his résumé and a list of his academic publications and past expert testimony.

In the remainder of the report, however, Carlton dismisses concerns about the threat to trademark owners, saying that they can be resolved by the creation of new procedures at ICANN. "Given ICANN's ability and incentive to modify existing procedures and adopt new ones that protect registrants' property rights, it would be a mistake at this time to address this concern through the draconian remedy of a ban on all new TLDs," he concludes.

The second Carlton report published by ICANN on Saturday is intended as a rebuttal of a critique of the earlier reports summarized in the first. "Comments on Michael Kende's assessment of preliminary reports on competition and pricing," responds, Carlton wrote, to a report commissioned by AT&T from Michael Kende of consultancy Analysys Mason.

In it, Carlton disagreed with Kende's remarks about defensive domain name registrations, saying that not all companies make multiple registrations in different TLDs to prevent cybersquatting: Some do so to boost traffic back to a central site.