The other image, the logo, is probably generic enough that it's used elsewhere and a user is likely to have it cached. The other looks bespoke for this page, so wouldn't.
I don't understand how it validates - I'd always understood that html, head, [title] and body were required for a complete document. Certainly the draft spec at http://www.w3.org/TR/html5/semantics.html#the-html-element-0 appears to confirm this ...
Fairplay to them though, they got a semantically and structurally deficient document to validate - it's like the IE6 of webpages ;0)
That's a strange version of "required". Basically the elements are not required in a document until parse time at which point they are inserted following an extremely arduously defined algorithm.
It seems bizarre to me that you wouldn't simply define the location of meta elements strictly as being in the head but instead define that should the parser find them they should be wrapped in to a head element.
On a brief view it looks like one can just drop a meta tag, say, in anywhere in the document and the parser has to move this to the head element?
I didn't realise that they were encouraging tag soup; this isn't part of the spec I've seen before. This sort of complex parsing algo wasn't in XHTML1.X or HTML4.X was it?
The complex parsing algorithm wasn't spelled out in excruciating detail, as it is in HTML5; much of it was implied, and left for the parser developers to figure out.
Strictly, the HTML, HEAD, and (BODY|FRAMESET) elements are required, in a valid document, but the tags delimiting them are optional. That way, code which manipulates the DOM can always count on a HEAD element being present, and CSS specifiers can use 'body' as a root, even if the tags themselves are missing from the source HTML file.
The first actual required tag in an HTML 4 document is <title>, as far as I know. Every HTML document has to have one, and it needs to be opened and closed explicitly. If it's the first thing in the document, it implies an <html><head> before it, and if body content comes after it, that will imply </head><body> as well.
You could put a <meta> tag anywhere before the first body content, and it would still be part of the implied HEAD element. As long as it doesn't come after the (explicit or implicit) </head> tag, it shouldn't cause the document to fail validation.
And no, none of this is valid XHTML. XHTML is always strict, and all opening and closing (or self-closing) tags must be present in the source file.
I don't think the older ones do; however, I'm sure Google gives them a different 404 page (change your User-Agent to IE6 and see how different the search results HTML is).
Which could be another indication why the Google logo itself is linked (besides it being in cache as well). The page degrades well imho in IE6 - the lack of the cutsey robot isn't essential to the page - the logo however is.
Base64 isn't exactly efficient. (Though it might be more efficient than an additional HTTP request. But if so, why aren't they using it for the homepage logo, say?) I wonder if they're using it as non-useless padding for stopping the IE-overrides-too-short-404s behavior.
