W3C home > Mailing lists > Public > public-powderwg@w3.org > August 2008

Re: HTTP Link, rel="powder" cf. rel="describedby"

From: Andrea Perego <andrea.perego@uninsubria.it>
Date: Fri, 01 Aug 2008 16:01:30 +0200
Message-ID: <4893173A.7070904@uninsubria.it>
To: Public POWDER <public-powderwg@w3.org>

Either "meta", "description", "describedby" are fine to me.

However, considering which is the common use of the Link's attribute 
@rel, and also based on the examples in [1], it seems to me that 
"description" or "meta" might be preferable to "describedby".

Suppose that the following Link's concern to a given resource 
http://www.example.org/:

1. Link: <http://www.example.org/toc.html>; rel="contents";
     type="text/html"

     i.e., "http://www.example.org/toc.html is the table of contents of
     http://www.example.org/, in HTML format"

2. Link: <http://www.example.org/style.css>; rel="stylesheet";
     type="text/css"

     i.e., "http://www.example.org/style.css is a stylesheet for
     http://www.example.org/, in CSS format"

3. Link: <http://www.example.org/rss/>; rel="alternate";
      type="application/rss+xml"

     i.e., "http://www.example.org/rss/ is an alternate version of
     http://www.example.org/, in RSS format"

So, here "contents" is used instead of (a more RDF-like) "hasContents", 
"stylesheet" instead of "hasStylesheet", etc.

Of course, it's just a matter of words, and if Mark has no objection in 
adopting "describedby" or something similar, then this is not an issue 
at all.

Andrea

[1]http://tools.ietf.org/html/draft-nottingham-http-link-header-02#section-4.2


Scheppe, Kai-Dietrich wrote:
> ...and one more...
> 
> I saw somewhere that rel defines a forward relationship with a document.
> Even in that sense describedby make a lot of sense.
> 
> -- Kai  
> 
>> -----Original Message-----
>> From: Smith, Kevin, (R&D) VF-Group [mailto:Kevin.Smith@vodafone.com] 
>> Sent: Friday, August 01, 2008 11:01 AM
>> To: Phil Archer; Scheppe, Kai-Dietrich
>> Cc: Public POWDER
>> Subject: RE: HTTP Link, rel="powder" cf. rel="describedby"
>>
>> +1 to 'describdBy'; makes sense to me :)
>>
>> -----Original Message-----
>> From: public-powderwg-request@w3.org
>> [mailto:public-powderwg-request@w3.org] On Behalf Of Phil Archer
>> Sent: 01 August 2008 09:58
>> To: Scheppe, Kai-Dietrich
>> Cc: Public POWDER
>> Subject: Re: HTTP Link, rel="powder" cf. rel="describedby"
>>
>>
>>
>>
>> Scheppe, Kai-Dietrich wrote:
>>> Hi,
>>>
>>> So what is your thought on what the rel type could be?  Rel="meta" 
>>> seems intuitiv, but is not regsitered.
>> That's a whole other can of worms - I've just written to a 
>> bunch of W3C folk about how a common view of registering @rel 
>> types should be done.
>>
>>> Is there such a thing as rel="description" or something similar?
>> No - but 'describedby' is in our POWDER-s vocab and, I think 
>> the GRDDL folk would like it too.
>>
>> P
>>
>>>> -----Original Message-----
>>>> From: public-powderwg-request@w3.org 
>>>> [mailto:public-powderwg-request@w3.org] On Behalf Of Phil Archer
>>>> Sent: Friday, August 01, 2008 10:21 AM
>>>> To: Public POWDER
>>>> Subject: HTTP Link, rel="powder" cf. rel="describedby"
>>>>
>>>>
>>>> I had a (very good) meeting with Mark Nottingham yesterday. 
>>>> He's Yahoo's point man at the IETF and the person behind the HTTP 
>>>> Link Header internet draft to which our DR doc refers [1].
>>>>
>>>> He seems happy that there is a good deal of consensus 
>> around most of 
>>>> the important issues that draft raises. The area where there is 
>>>> currently less consensus is how various relationship types 
>> should be 
>>>> registered and maintained. This goes way beyond POWDER in terms of 
>>>> scope but it clearly affects us since our docs talk about using 
>>>> rel="powder."
>>>> We've followed the current recommendations by using a profile 
>>>> document.
>>>>
>>>> Bottom line - with a bit of political negotiation - Mark believes 
>>>> that HTTP link will be able to progress along the route to 
>> RFC within
>>
>>>> the time line we need.
>>>>
>>>> But... whilst our use of HTTP Link is right in Mark's view, the 
>>>> registration of rel="powder" probably isn't. Section 4.2 
>> [2] of the 
>>>> draft says:
>>>>
>>>> "A Link relation is a way of indicating the semantics of a link.  
>>>> Link relations are not format-specific, and MUST NOT specify a 
>>>> particular format or media type that they are to be used with."
>>>>
>>>> I was concerned about this since rel="powder" /does/ indicate a 
>>>> particular format (i.e. POWDER). I raised this on the HTTP 
>> list and 
>>>> Jonathan Rees replied [3] that he thought this referred to 
>> the origin
>>
>>>> of the link, not its target. Mark said no - actually the 
>> intention is
>>
>>>> that /neither/ end of the link should be format-specific - 
>> that's the
>>
>>>> job of the MIME type.
>>>>
>>>> I said that we were wary of trying to register a new MIME type - 
>>>> after all, POWDER is either XML or RDF/OWL (semantic extension
>>>> notwithstanding) and that HTML Profile meant we didn't /need/ to 
>>>> register either rel="powder" or a new MIME type. Well...
>>>> that's true but we are talking about registering the @rel type so 
>>>> that argument rather loses potency!
>>>>
>>>> Mark pointed me to a doc [4] that is an entry point for a 
>> description
>>
>>>> of how we would register the POWDER Media type which 
>> actually looks 
>>>> pretty simple - being in a W3C Rec document means that 
>> IETF is likely
>>
>>>> to agree to the new type with little delay.
>>>>
>>>> To get to the point, Mark's recommendation is that we
>>>>
>>>> 1. Use a more generic @rel type of describedby (something other 
>>>> groups want as well btw)
>>>>
>>>> 2. Register a POWDER-specific Media type. I guess ours would be
>>>>
>>>> application/powder+xml
>>>>
>>>> and
>>>>
>>>> application/powder-s+xml
>>>>
>>>> ???
>>>>
>>>> Neither of these registration steps is particularly hard to do.
>>>>
>>>> In terms of the WG's process, I suggest we teat this as a 
>> Last Call 
>>>> comment and deal with it when we resume in September - *unless* - 
>>>> Matt -
>>>>   you advise that /if/ we were to make such a change we'd 
>> require a 
>>>> new LC version, in which case we may need to take a couple of 
>>>> resolutions by e-mail before those docs you're working on 
>> are fully 
>>>> published (er, which I believe is scheduled for a week today)
>>>>
>>>> Phil.
>>>>
>>>>
>>>>
>>>> [1] http://tools.ietf.org/html/draft-nottingham-http-link-header-02
>>>> [2]
>>>> http://tools.ietf.org/html/draft-nottingham-http-link-header-0
>>>> 2#section-4.2
>>>> [3]
>>>>
>> http://lists.w3.org/Archives/Public/ietf-http-wg/2008JulSep/0122.html
>>>> [4] http://www.w3.org/2002/06/registering-mediatype
Received on Friday, 1 August 2008 14:02:17 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:42:13 GMT