I can understand .co indicating it will abide by those rules and think that is a good thing, but what requires them to do so other than their decision to do so?
It's part of their marketing plan to be a knockoff of .COM. The .US domain has had a dispute policy similar to the UDRP since 2002. It seems to be rarely used, and I only see nine cases, most of which are pretty egregious, like a guy who registered federalrepublicofgermany.us and bundesrepublikdeutschland.us, to which the German government objected in 2005. But .US, unlike .CO, has a nexus requirement so you have to show (or at least claim) a connection to the US, so it's reasonable that US style trademark rules apply. The .CA domain also has a dispute policy somewhat like the UDRP, although the registry assigns the arbitrator. They also have nexus rules, so Canadian law is appropriate. Nominet for .UK has a multi-stage dispute process starting with informal mediation, then an expert decision by one or on appeal three experts from a panel maintained by Nominet. Some parts of .UK have nexus rules, but .CO.UK doesn't. All of these are similar in intent although different in detail, and the latter three are all adapted to local conditions, e.g., the Canadian one addresses language issues. It seems to me that any country with trademark laws is likely to see some friction from trademark claims, but I don't see any reason to use the UDRP to deal with them as opposed something adapted to local law and customs. R's, John