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> P.S. Why the trailing slash on the tag? It’s completely useless, by definition, and trailing slashes can mislead people into thinking that you can close tags that way, which you can’t. Simple: so that XML parsers can load the HTML, as they are not aware of the HTML context which allows "unclosed" tags.
You wouldn’t parse an HTML document with regular expressions. So why would you parse one with an XML parser? It’s just wrong . (And an effort doomed to failure if you ever have to deal with documents other people wrote, because very few will parse.)
There are a lot of more XML parser than HTML5 parser in the world. That's an argument for polyglot markup, if you like the open web and HTML as an API.