The browser accessibility implementation story for a slew of new HTML features is recorded on HTML5 accessibility (on github). It’s a proposal that has been rejected, it only lives on in the whatwg spec because hixie decides what’s in his spec. The process of cell reproduction and division are classified into two types; mitosis and meiosis. Oooops! Dude, if you’re going to spec features, please for the love of kittens provide use cases, data, and talk to real users and developers. ; The html element's height and width are controlled by the browser window. we should not mix HTML and WAI-ARIA but leave them to handle what each does best – avoiding assumptions that HTML will handle the accessibility (WAI-ARIA is Not not needed). It’s unfortunate that your understanding of the features of AT is limited, users already have a plethora of methods to navigate smaller chunks of content: they have keystrokes to navigate paragraphs,headings, lists, tables, table rows, images, articles, forms, form controls, link, fieldsets, frames etc. Especially with site-wide navigation being very normal at the top of the document. a header/footer on the page then use main to markup the main content area, refer to Easy content organisation with HTML5.