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ISSUE-2100 (@rel/@rev prefixes): @rel/@rev values do not necessarily need to be prefixed [Last Call: SVG 1.2 Tiny ]

From: SVG Working Group Issue Tracker <sysbot+tracker@w3.org>
Date: Fri, 10 Oct 2008 14:25:34 +0000 (GMT)
To: public-svg-wg@w3.org
Message-Id: <20081010142534.32E2B6B62C@tibor.w3.org>


ISSUE-2100 (@rel/@rev prefixes): @rel/@rev values do not necessarily need to be prefixed [Last Call: SVG 1.2 Tiny ]

http://www.w3.org/Graphics/SVG/WG/track/issues/2100

Raised by: Doug Schepers
On product: Last Call: SVG 1.2 Tiny 

Manu Sporny (RDF in XHTML Task Force)
<http://lists.w3.org/Archives/Public/www-svg/2008Oct/0052.html>:
[[
@rel/@rev values do not necessarily need to be prefixed
-------------------------------------------------------

http://www.w3.org/TR/SVGMobile12/metadata.html#MetadataAttributes
"""
When used with RDFa, the values for the 'rel' and 'rev' attributes must
be a CURIE [RDFA] (i.e., a prefixed string, such as 'cc:license' to
indicate a Creative Commons license), while the values may simply be
from a set of specific keywords for Microformats. These formats may be
used independently, or in combination if the keywords do not clash.
"""

The @rel/@rev values in RDFa can either be a reserved word or a CURIE as
defined in the RDFa Syntax document[2]. Perhaps the SVG Tiny document is
authored to not support reserved words due to a mis-reading or
mis-understanding of the current CURIE specification[3]? The current
specification allows both prefixed and unprefixed "reference only" values:

http://www.w3.org/TR/curie/#s_syntax
"""
curie       :=   [ [ prefix ] ':' ] reference
...
A host language MAY interpret a reference value that is not preceded by
a prefix and a colon as being a member of a host-language defined set of
reserved values. Such reserved values MUST translate into an IRI, just
as with any other CURIE.
"""

We urge the SVG WG to not limit CURIEs and provide a CURIE mechanism as
defined by the CURIE specification. It would make the job of RDFa parser
authors much easier as there are less special cases to consider when
creating their parser. The current language in SVG Tiny requires all
current RDFa parsers to strip out all reserved word processing in order
to conform to SVG+RDFa, which would lead to two increasingly divergent
types of RDFa parsers:

1. Parsers that parse SVG+RDFa 1.0.
2. Parsers that parse "XHTML+RDFa 1.0".

The SVG Tiny document seems to insist that terms must be of the form
"x:y", instead of also allowing things like "license" (note that there
isn't a preceding colon before a reserved word).

We are currently working on a method to specify reserved words that will
not need preceding colons and the current language in SVG Tiny would
prevent that method from being used in SVG Tiny.

Please do one of the following:

* Adopt the current RDFa/CURIE processing rules as-is.
* Define a set of reserved words that should be used in SVG Tiny and
  preserve the functionality provided in the CURIE Specification.
* Do not rule out the ability to use non-colon-prefixed reserved words.

[2] http://www.w3.org/TR/rdfa-syntax/#relValues
[3] http://www.w3.org/TR/curie/

]]
Received on Friday, 10 October 2008 14:26:09 GMT

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