>>I'm sorry but I disagree with you. It's not an HTML tag but just a text that happen to include the less than and greater than sign. There's no reason to treat is as HTML tag.
>
>How can you determine if it is or not? This is where the issue is. There is nothing to rely on but to maintain a table of all the HTML tags and that can change at any time.

I hardly think they will add any more tags. Only a few tags have been added over the last few years, since most changes now are done via CSS. MSFT has stated that default for the next browsers will be transitional HTML, but may change to XHTML sooner than we think. I guess Opera, Chrome, Firefox and the rest will follow the same pattern.