AFAIK, "site" isn't a stand-alone sort of thing, that's the part that has to be defined. [site=livejournal.com user name=boji] would work, because it's just reordering the elements "user", "name=boji", and "site=livejournal.com". In coding terms, "site name=livejournal.com" is very different from "site=livejournal.com".

In other words, "name=" is always going to refer to an account/individual, not a domain. If you try to set name=domain.com, the site doesn't understand what you're trying to tell it.