It literally talked about the domain names. Interestingly the quote is outdated. They changed that section since it was quoted on the wiki. When I try to look up definitions, domain seems to be the synonym of domain name. If I were to refer to the services provided under a domain, I would not use the term domain. We refer to Itch.io as a site and not as a domain. A domain is the adress of a house and not the house itself.
Prohibiting names would make a lot of sense and restrictions about naming are useful. There are defamatory sites that have the defamation in their domain name. And insulting polititicans is illegal in many countries.
What they actually mean is unknown to me. Because they obviously do not make use of that policy in the sense of that vague catch it all phrasing. "statutory laws of any Nation" includes countrys like Russia and China. Itch is banned in those countries. And outright illegal in Russia because of lgbt laws. So it is either: they ignore that rule or it does not apply.