Re: survey of top web sites

On 25 Apr 2007, at 21:08:09, Sean Fraser wrote:

> The first ranked most popular Alexa site, Yahoo!, adresses your  
> points above.
>
> W3C HTML Validation = 33 errors [http://validator.w3.org/check? 
> uri=http%3A%2F%2Fwww.yahoo.com%2F]

However this is misleading, in that Yahoo! uses server-side sniffing  
to serve different content to different user agents. I get the same  
33 errors for HTML validation if I simply give the validator the URL  
of Yahoo!'s home page, but viewing the source used by the validator  
shows that it is completely different to the source sent to my copy  
of Firefox, Safari or IE.

As Yahoo!'s servers don't recognise the validator's User-Agent header  
as being one of their A-Grade browsers [1] it sends the nested-table  
version intended for X-grade browsers. Interestingly, using the FF  
Web Developer extension's "Validate local HTML" option gives 272 HTML  
validation errors.

Perhaps this could be addressed by allowing users of the validator to  
specify a particular UA header to be used when retrieving a page for  
validation.

[1] <http://developer.yahoo.com/yui/articles/gbs/>

Regards,

Nick.
-- 
Nick Fitzsimons
http://www.nickfitz.co.uk/

Received on Thursday, 26 April 2007 19:45:29 UTC