W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > September 2001

Re: URI terminology demystified

From: Dan Connolly <connolly@w3.org>
Date: Thu, 20 Sep 2001 08:59:50 -0500
Message-ID: <3BA9F656.F271A92F@w3.org>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
CC: w3c-rdfcore-wg@w3.org
Jeremy Carroll wrote:
> 
> Dan wrote:
> 
> >
> > see the W3C charmod spec (and the HTML 4.01 spec,
> > and the XLink spec, and a recent IURI internet draft) for official
> > specification of this unicode-to-URI stuff.
> >
> 
> Dan,
> 
> the charmod spec is currently a Last Call working draft.

charmod is a relatively recent specification of this
feature, but the feature itself is baked into HTML 4.0,
XML 1.0, XLink, and RDF 1.0:


  Note: Although non-ASCII characters in URIs are not allowed by [URI],
[XML]
  specifies a convention to avoid unnecessary incompatibilities in
extended URI
  syntax. Implementors of RDF are encouraged to avoid further
incompatibility and
  use the XML convention for system identifiers. Namely, that a
non-ASCII character
  in a URI be represented in UTF-8 as one or more bytes, and then these
bytes be
  escaped with the URI escaping mechanism (i.e., by converting each byte
to %HH,
  where HH is the hexadecimal notation of the byte value). 

By that wording, non-ascii characters in rdf:resource are
an error, and there's a suggested way to recover from the error.
By the more modern specs (XLink, charmod) this is no longer
an error but a 1st class feature.

I guess it's not totally obvious that we should follow XLink
on this, but if we don't, we owe the I18N WG a last-call
comment on charmod saying we're not going along with this.
I expect they wouldn't be happy.

> If we want to punt this sort of issue to I18N WG by referring to charmod
> is it allowed?

The I18N WG has given its answer in the charmod spec; it's a question
of whether we want to follow along.

> Or do we need to punt to something further along the standardization
> process, or can we punt to a future document.

No, RDF 1.0 had the above note, and I think following charmod
is a reasonable interpretation of it.

> e.g. to the successor of charmod in the W3C track ...
> 
> I am thinking particularly about:
> 
>   rdf:about=URI-reference
> 
> and
> 
>   Unicode Normalization
> 
> Also:
> 
> will charmod finish soon (before us?).

I'm not sure when charmod will finish, but as I say,
it doesn't really matter: there are plenty of RECs
for precedent (XLink, at least).

> Jeremy

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Thursday, 20 September 2001 09:01:02 EDT

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