Proper nouns and HTML

Rui wrote a post about the use of the "õ" character in XHTML. I tried to comment but something went wrong with it, so here's a post about it:

Propper Nouns are untranslatable, so my name is Marcos Marado wherever I am or whichever the language I'm talking is. The same way, Paula Simões is called Paula Simões either I'm talking about her in Portuguese, English or Japanese. So, if I'm talking in English and I want to refer to Paula, I should say "Paula Simões", and this doesn't mean that I'm "mixing languages": Proper nouns are universal, they have no nationality and are untranslatable. It's the same as "Internet", there's no translation for that. When you have to use such entities, you must write them this way:

ã turns ã
á turns á
à turns à
â turns â

...and so on. There's nothing wrong in the way Paula writes her name in her website, nor does it affect the page's ranking on search engines (not that I believe that she's trying to apply any kind of SEO technique on her website).