> Not using quotes relies on browsers that have always made a best-effort attempt to parse even the most badly broken HTML. Not using quotes is actually fully

> Not using quotes relies on browsers that have always made a best-effort attempt to parse even the most badly broken HTML. Not using quotes is actually fully permitted by the HTML5 spec, although use of quotes is recommended. The HTML5 spec formalises this. The HTML5 spec is somewhat noteworthy in that it was actually put together and agreed upon by the browser vendors/developers, and then became a W3C spec (previously, this has occurred the other way around). HTML5 parsing formalises much of the previous leniency / workarounds.