Dear colleagues, Regarding open issue I.2 Whether registrars that are queried for a name they don't sponsor should respond with HTTP 404 as a MUST or have the option to redirect (section 3.1.2 in v06) in the gTLD RDAP profile. In section 3.1.2 of v12 we left the MUST for registrars to return an HTTP 404 for names they don’t sponsor. Registries are the authorative source of information, if a Registry says that a registrar is the sponsoring registrar, but the registrar is not sponsoring the domain, something is broken. HTTP 404 seems the most accurate way to indicate this. It is true that RDAP uses HTTP, which requires support for loop detection, however the registries do not redirect, they provide a link member as defined in the profile, therefore, the built-in HTTP loop detection mechanism might not work if the registrar offers a redirection to the registry. In any case, we are deferring changing the current draft requirements until/if there is consensus from the community to do so. Your input is welcome. Regards, -- Francisco.