Search notes:

HTML element: html

A <html> element has two child elements: <head> and <body>, in that order.

In JavaScript, the <html> element can be accessed with document.documentElement.

lang=

<html lang="de">
  …
</html>

Compare to <meta http-equiv="content-language" content="de">

AMP

Apparently, in order to identify AMP (Accelerated Mobile Pages) documents, their opening tag has a high voltage symbol (Unicode U+26A1): <html ⚡>.

See also

CSS:

CSS: the <html> and <body> tag
Root element/canvas: Styles for body with/without styles for html element

When rendered in a web browser, the <html> element can be accessed in JavaScript and DOM with the document.documentElement().