HTML5
When this option is selected for the Doctype Declaration attribute, the following is placed at the beginning of the generated HTML page: <!DOCTYPE HTML> This declares the document to be HTML5, which is not based on SGML and therefore does not require a reference to a DTD like other doctype declarations. It's the fifth revision of the HTML standard and its core aims have been to improve the language, adding support for the latest multimedia content, while keeping code easily readable by humans and consistently understood by computers and devices. HTML5 is intended to subsume not only HTML 4, but also XHTML 1 and DOM Level 2 HTML.