W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > June 2008

Re: ISSUE-121: CR Comment: clarification of default namespace

From: Mark Birbeck <mark.birbeck@webbackplane.com>
Date: Thu, 19 Jun 2008 22:05:16 +0100
Message-ID: <ed77aa9f0806191405q736d06a2tf331614127ffff83@mail.gmail.com>
To: RDFa <public-rdf-in-xhtml-tf@w3.org>
Cc: "SWD Working SWD" <public-swd-wg@w3.org>


> section 7 says the RDFa default prefix mapping is
> http://www.w3.org/1999/xhtml/vocab# and has to be used when the prefix but
> not the colon is omitted in a CURIE. At the bottom of page 53 is then said
> that "the mapping to use with the default prefix is the current default
> mapping" which would be the value of @xmlns in scope and therefore normally
> http://www.w3.org/1999/xhtml (section 4.1).

The top of that section says:

  "...in RDFa the 'default prefix' mapping is

So perhaps we could make this clearer at the bottom of the section by saying:

 "the mapping to use with the default prefix is the current default
prefix mapping"

I.e., adding the word "prefix".

> According to that, in Test 63 the predicate would be
> http://www.w3.org/1999/xhtmlnext rather than
> http://www.w3.org/1999/xhtml/vocab#next (rel=":next"). Additionally, page 29
> states that the prefix http://www.w3.org/1999/xhtml/vocab# should be used
> only for values in @rel/@rev without prefix and colon. Please correct me if
> I misunderstood this part.
> """

I'm having trouble working out what part of the spec this is referring
to, because of the page number thing.

But the intention is that the @rel/@rev values are 'tokens' that map
to a URI. In other words, they are not 'unprefixed' values that then
acquire a prefix. It just so happens that all of the 'fixed' values
map to URIs in the XHTML vocab space, but one of the tokens could just
as easily map to a URI in some other space.

The confusion probably arises because the CURIE syntax *in general*
does allow for unprefixed values, and explains how they should be
processed. But it also allows for a list of reserved values to be
defined, and that is the feature that we are using for @rel/@rev
values, and therefore why we say "the mapping to use when there is no
prefix is not defined".


Mark Birbeck, webBackplane



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Received on Thursday, 19 June 2008 21:18:25 UTC

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