Doctype - sgml/signature GitHub Wiki

https://flaviocopes.com/doctype/ https://vuejsfeed.com/blog/test-websites-for-speed-mobile-friendliness-security-and-the-html5-doctype-using-blib-powered-by-vue-js https://www.campaignmonitor.com/blog/email-marketing/2014/08/html5-vs-xhtml1-the-right-doctype-to-use-in-html-email/ http://omegacoder.com/?p=351 https://trends.builtwith.com/docinfo/doctype-declaration