I’ve been reading the HTML specifciation and I am confused with this line:
The nodes representing HTML elements in the DOM must implement, and
expose to scripts, the interfaces listed for them in the relevant
sections of this specification. This includes HTML elements in XML
What HTML elements have to do with xml documents? Somewhat vague description makes things even more complicated:
To ease migration from HTML to XML, UAs conforming to this
specification will place elements in HTML in the
http://www.w3.org/1999/xhtml namespace, at least for the purposes of
the DOM and CSS. The term “HTML elements” refers to any element in
that namespace, even in XML documents.
What kind of migration? Who is UA? What is this http://www.w3.org/1999/xhtml namespace? How can URL be a namespace? And again, what HTML elements have to do with XML document?