People might have names, but they're not always known: you admit an unconscious patient amongst many (e.g. a bus/plane/whatever accident), unclear whose documen

People might have names, but they're not always known: you admit an unconscious patient amongst many (e.g. a bus/plane/whatever accident), unclear whose documents are whose (and whether there even are any), now what? USA has the assumed name John/Jane Doe - but that has obvious pitfalls of its own.