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Re: new issue? squatting on link relationship names, x-tokens, registries, and URI-based extensibility

From: Mark Nottingham <mnot@mnot.net>
Date: Tue, 12 Apr 2005 09:12:27 -0700
Message-Id: <83e1a1a25da1931826da8c22c25748d2@mnot.net>
Cc: Dan Connolly <connolly@w3.org>, www-tag@w3.org
To: ht@inf.ed.ac.uk (Henry S. Thompson)

 From the latest Atom I-D:

>    atom:link elements MAY have a "rel" attribute that indicates the 
> link
>    relation type.  If the "rel" attribute is not present, the link
>    element MUST be interpreted as if the link relation type is
>    "alternate".
>
>    The value of "rel" MUST be string that is non-empty, does not 
> contain
>    any colon (":") characters, and matches the "isegment-nz-nc" or 
> "IRI"
>    production in [RFC3987].  Note that use of a relative reference is
>    not allowed.  If a name is given, implementations MUST consider the
>    link relation type to be equivalent to the same name registered
>    within the IANA Registry of Link Relations Section 7, and thus the
>    IRI that would be obtained by appending the value of the rel
>    attribute to the string "http://www.iana.org/assignments/relation/".
>    The value of "rel" describes the meaning of the link, but does not
>    impose any behavioral requirements on implementations.
>
>    This document defines five initial values for the Registry of Link
>    Relations:
>
>    1.  The value "alternate" signifies that the IRI in the value of the
>        href attribute identifies an alternate version of the resource
>        described by the containing element.
>
>    2.  The value "related" signifies that the IRI in the value of the
>        href attribute identifies a resource related to the resource
>        described by the containing element.  For example, the feed for 
> a
>        site that discusses the performance of the search engine at
>        "http://search.example.com" might contain, as a child of
>        atom:feed:
>
>        <link rel="related" href="http://search.example.com/">
>
>        An identical link might appear as a child of any atom:entry 
> whose
>        content contains a discussion of that same search engine.
>
>    3.  The value "self" signifies that the IRI in the value of the href
>        attribute identifies a resource equivalent to the containing
>        element.
>
>    4.  The value "enclosure" signifies that the IRI in the value of the
>        href attribute identifies a related resource which is 
> potentially
>        large in size and may require special handling by consuming
>        software.  For Link elements with rel="enclosure", the length
>        attribute SHOULD be provided.
>
>    5.  The value "via" signifies that the IRI in the value of the href
>        attribute identifies a resource that is the source of the
>        information provided in the containing element.



>
On Apr 12, 2005, at 2:39 AM, Henry S. Thompson wrote:

> Mark Nottingham <mnot@mnot.net> writes:
>
>> Atom does take an interesting approach WRT what you discuss below; the
>> content of @rel can have two syntactic forms; it can either be an
>> absolute URI, or it can be a token which is treated as a URI-reference
>> with a fixed base (that of the IANA registry for that token
>> namespace).
>
> Could you expand just a bit -- "token namespace"?  Where is that
> declared/bound/found. . .?
>
> ht
> -- 
>  Henry S. Thompson, HCRC Language Technology Group, University of 
> Edinburgh
>                      Half-time member of W3C Team
>     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
>             Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
>                    URL: http://www.ltg.ed.ac.uk/~ht/
> [mail really from me _always_ has this .sig -- mail without it is 
> forged spam]
>
>

--
Mark Nottingham     http://www.mnot.net/
Received on Tuesday, 12 April 2005 16:12:32 GMT

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