Sorry, I mistook "that is rendered from the domain" for "rendered from a resource from the domain".

However, teach users to read domain names! If users do not grasp the general concept, e.g., if the supposed identity is just "example" (possibly with some decoration considered insignificant) and not "example.com", how are they supposed to survive? Domains have been around for more than a quarter of a century, the Internet is actually part of our lives… There is no excuse, and there is no sense in pretending that there was no harm in not understanding the basics. That said, there are real ambiguities that have to be addressed.