RE: [whatwg] Section 3 semantics and structure

HTML5 elements live in the DOM, and markup creates two (preferable) ways to
persist HTML5 documents and fragments.  But in principle you could persist
them as JSON equally well (probably making your site inaccessible to bots),
with a few framework exceptions just to bootstrap the browser.  It is quite
surprising at the first sight.
HTH,
Chris