You're unintentionally hilarious. You know nothing about Google's technological challenges nor the decisions behind the various circumstances where they chose to ignore the standard.
I guarantee you that there are thousands of people working at Google who are:
Google's pages don't validate. Nobody's claiming there isn't a reason for it. Naturally, one would expect Google to adhere to the standards. As you point out yourself, they're smart enough to understand them. This is old news. Why is it relevant today? Because Google just released mod_pagespeed (http://news.ycombinator.com/item?id=1865249), an Apache module that speeds up pages by rewriting them, using filters based on optimizations developed by Google over the years. If you're a web developer that works under the requirement that all pages are valid HTML, it's important to consider the source before jumping on the mod_pagespeed bandwagon.
Google might have their reasons to ignore the standards—but I very much doubt of their validity. E.g. all those bgcolor=#ffffff text=#000000 link=#0000cc vlink=#551a8b alink=#ff0000 attributes onbody element. You may claim that these are intended to support the older browsers which have no CSS support.
Well, dissable CSS and take a look at google.com to see how much water does this argument hold.
And even if there are valid reasons for invalid markup, there is no reason to have DOCTYPE of the actuall standard if you are not going to follow it.
> And even if there are valid reasons for invalid markup, there is no reason to have DOCTYPE of the actuall standard if you are not going to follow it.
Sure there is. They want browsers to render the page with the latest standards support, even if they have a few trivial violations of that standard.
So sad to see you upvoted, it just shows how little people do know about how HTML, browsers and doctypes interact.
Browsers don't look at doctype and then choose what to support and what not: they will always try their best. See for yourself: http://kod.as/lab/html5/html32.html —that's HTML5
code with <canvas> but with HTML3.2 doctype. Try it in modern browser, canvas still works.
Let me repeat: browsers will always try to render all they can on the page, no matter if that feature was or not in the version of HTML page claims to be. The only thing doctype
affects is rendering mode. Any unknown doctype will trigger browsers to render the page in standards compliant mode. This feature is the reason why HTML5 has a doctype declaration at all. If you use XHTML5 (i.e. use xml markup and server your document with MIME application/xml+xhtml) you can omit doctype, because MIME type then tells browser which rendering mode to use.
strong, b, i, and small tags had their semantic meanings changed in HTML5. Thus, a HTML5 doctype gives some information to browsers and search engines on how those tags should be interpreted.
Screen readers may treat small as optional text, as it's intended as the inline equivalent of the aside block-level tag. b and i are likely going to wind up having ramifications for how screen reading browsers apply emphasis, as they now have semantic instead of presentational meaning.
