W3C home > Mailing lists > Public > public-html@w3.org > February 2011

Re: ISSUE-124: rel-limits - Straw Poll for Objections

From: Philip Jägenstedt <philipj@opera.com>
Date: Sun, 27 Feb 2011 17:53:20 +0100
To: public-html@w3.org
Message-ID: <op.vrkmi3qfsr6mfa@nog>
On Sun, 27 Feb 2011 14:08:49 +0100, Julian Reschke <julian.reschke@gmx.de>  
wrote:

>> Finally, the change proposal doesn't specify how to handle conflicting  
>> information like this in a page:
>>
>> <link rel="stylesheet noreferrer" href="foo.css">
>> <link rel="stylesheet nofollow" href="foo.css">
>>
>> Is the effective set of keywords "noreferrer", "nofollow" or  
>> "noreferrer nofollow"? Presumably both browsers and search engines  
>> would be clever enough to only issue one request, but should the search  
>> engine consider "that the link is not endorsed by the original author  
>> or publisher of the page" and should a browser "not include a Referer  
>> (sic) HTTP header"?
>
> As stated earlier, this is a general problem you get with the concept of  
> link relations. It's not specific to this case, and we should treat this  
> as a distinct problem.
>
> So, the answer to "how many request" should be the same as for:
>
> <link rel="stylesheet bar" href="foo.css">
> <link rel="stylesheet foo" href="foo.css">
>
> ...and the answer about the semantics is: those of "noreferrer" and  
> "nofollow". If these are in conflict, it's a problem for <a> as well.

The issue is not "how many requests?", but "which headers?" Maciej  
summarized/clarified my argument quite well in  
<http://lists.w3.org/Archives/Public/public-html/2011Feb/0356.html>.  
AFAIK, no other link type affects which HTTP headers are sent, so the  
problem of how to combine several <link> requests into one has not arisen  
before, and can never arise for <a>.

> Edward O'Connor writes:
>
>> As pointed out by Philip, such a change would introduce a race  
>> condition in the loading of stylesheets, and thus fails to have  
>> Well-defined Behavior  
>> <http://www.w3.org/TR/html-design-principles/#well-defined-behavior>.  
>> The positive effect claimed ("less special-casing") is appealing, but  
>> theoretical purity is at the bottom of our Priority of Constituencies  
>> <http://www.w3.org/TR/html-design-principles/#priority-of-constituencies>.  
>> This race condition is a potential source of confusion for web authors,  
>> and thus this CP puts theoretial purity ahead of web authors, inverting  
>> our Priority of Constituencies.
>
> As far as I can tell, Philip didn't point out a "race condition".

What Edward is referring to is probably this example:

<link rel="stylesheet" href="foo.css">
<!-- potential network lag here -->
<link rel="stylesheet noreferrer" href="foo.css">

Some (bad) solutions to the problem would result in a race condition, but  
all I've asked for is a solution to evaluate.

-- 
Philip Jägenstedt
Core Developer
Opera Software
Received on Sunday, 27 February 2011 16:54:00 UTC

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