Paul Irish recently shined a light on the Google 404 page in his talk on the primitives of HTML5: https://www.youtube.com/watch?v=WxmcDoAxdoY https://www.youtub

Paul Irish recently shined a light on the Google 404 page in his talk on the primitives of HTML5: https://www.youtube.com/watch?v=WxmcDoAxdoY https://www.youtube.com/watch?v=WxmcDoAxdoY (around 19:20). In the talk, he explains that all this is valid HTML5. You don't need quotes, you don't generally need closing tags. Whether you choose to them depends on how dirty it makes you feel, but few browsers will actually care. A separate but related lesson is that Google cares a ton about performance, so you'll often find these byte-saving tricks in high-traffic Google pages. e.g. the use of "//foo.com" instead of "http://foo.com http://foo.com.