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Re: Unicode NFC - status, and RDF Concepts

From: Jeremy Carroll <jeremy@topquadrant.com>
Date: Tue, 11 Oct 2011 12:02:46 -0700
Message-ID: <4E9492D6.3020407@topquadrant.com>
To: "Phillips, Addison" <addison@lab126.com>
CC: "Martin J. Dürst" <duerst@it.aoyama.ac.jp>, John Cowan <cowan@mercury.ccil.org>, "www-international@w3.org" <www-international@w3.org>, RDF Working Group WG <public-rdf-wg@w3.org>
On 10/11/2011 7:49 AM, Phillips, Addison wrote:
> XML is an interesting case because it makes the opposite decision 
> consciously: two canonically-equivalent but unequal identifiers are 
> not equal. XML provides recommended naming rules that avoid the 
> various problems of normalization (Appendix J in XML 5th Edition) for 
> precisely this reason. This is not an invalid solution, but the I18N 
> WG is trying to highlight this issue one last time before all 
> specifications go down this route. I do not think we're going to 
> change XML, but this should not dissuade other document formats, even 
> those based on XML, from normatively addressing normalization issues.


Addison, Martin,

my attempt to summarize this discussion for the RDF people is as follows:

9 years ago, at the Cannes tech plenary, I18N-WG advised RDF Core  WG 
(i.e. Martin advised me!) that early uniform normalization was the way 
to go, but that there was still debate about other approaches.

As a result RDF Core WG deferred to the IRI draft for IRI normalization, 
and used SHOULD language around literal normalization.

The situation now, is that there is still debate in the I18N community, 
and there is less consensus around early uniform normalization than before.

Hence, reasonable options for RDF WG are

A)
1) drop the informative reference to the normalization section of 
charmod, but otherwise make no change
B)
2) drop the "SHOULD use NFC" requirement on literals
C)
3) update the informative reference to the normalization section of 
charmod, but it is unclear quite to what since the situation has become 
more confused since the 2004 publication

RDF systems do compare literals fairly frequently, but not usually as 
'identifiers'

I guess I am saying that RDF Concepts did "normatively address 
normalization issues" but it seems that that is a moving target, so 
maybe it was an error to try.


Jeremy
Received on Tuesday, 11 October 2011 19:03:18 GMT

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