Re: Change Proposal for ISSUE-125

On Wed, 17 Nov 2010 21:11:59 +0100, Roy T. Fielding <fielding@gbiv.com>  
wrote:
> On Nov 17, 2010, at 2:34 AM, Anne van Kesteren wrote:
>> It is not true at all that browsers follow HTTP for <meta http-equiv>.
>
> That is irrelevant.  http-equiv is not a requirement on browsers to *do*
> anything.

These days it is.


> It is metadata of a defined form, syntax, and semantics.
> META exists in HTML because a lot of non-browser applications believe
> that metadata should be managed within the document file instead of
> in some external data store.  http-equiv exists because it provides
> a standard namespace for metadata that lots of Web-related applications
> care about, which was known to be valuable even back in the days before
> scope could be defined via xmlns or profile attributes.

These days <meta http-equiv> is used for setting the character encoding of  
a page, or causing a refresh or redirect.


>> Not all HTTP headers supported at the HTTP layer are supported in <meta  
>> http-equiv> either. Only a couple. Furthermore, per HTML4 <meta  
>> http-equiv> was some preprocessing instruction for servers, that never  
>> got implemented. So restoring the original text -- assuming you are  
>> referring to HTML4 -- would not work either.
>
> There was a description of how it *could* be used for server-side  
> processing, which actually was implemented directly by some servers  
> (e.g., WN) and indirectly via crontab by many others (e.g., to feed  
> Apache var maps).  Regardless, the syntax and semantics continues to be  
> implemented by many authoring tools.
> Restore the original HTML 2.0 text if you like.
>
> We have gone over this before.  Browser behavior does not completely  
> define HTML as a markup language.  The fact that some browsers started  
> using that metadata as a backup (and, in some cases, a replacement) for  
> HTTP metadata when it was not present in an HTTP response does not imply  
> that the new definition of the mark-up language is reduced to what some  
> subset of browsers do upon seeing that metadata.  The only thing such  
> behavior needs from the standard is an additional paragraph or two that  
> states when, where, and how such browser behavior occurs.  The original  
> definitions are still implemented and
> relied upon by the vast majority of vendors that also depend on the HTML
> standard, even though they are not implementing a browser.

It would be interesting to see these authoring tools and/or examples of  
web pages created by them. I suspect there are more authoring tools that  
use <meta http-equiv> values solely to instruct browsers.


-- 
Anne van Kesteren
http://annevankesteren.nl/

Received on Thursday, 18 November 2010 10:19:19 UTC