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Re: Language Tag Case Conflict (between RDF1.1 and BCP47)

From: Hong Sun <hong.sun@agfa.com>
Date: Fri, 29 Mar 2013 16:50:58 +0100
To: gavin@carothers.name
Cc: David Wood <david@3roundstones.com>, Ivan Herman <ivan@w3.org>, public-rdf-comments Comments <public-rdf-comments@w3.org>
Message-ID: <OF93BFBFAE.F565F896-ONC1257B3D.0056E420-C1257B3D.0057114C@agfa.com>
Thanks Gavin,

You are right, it is mainly for the RDF1.1 concept.

Kind regards,

From:   Gavin Carothers <gavin@carothers.name>
To:     David Wood <david@3roundstones.com>
Cc:     Ivan Herman <ivan@w3.org>, public-rdf-comments Comments 
<public-rdf-comments@w3.org>, Hong Sun/AXIFX/AGFA@AGFA
Date:   03/29/2013 04:30 PM
Subject:        Re: Language Tag Case Conflict (between RDF1.1 and BCP47)

On Fri, Mar 29, 2013 at 8:13 AM, David Wood <david@3roundstones.com> 
Hi Hong Sun and Ivan,

Do I understand correctly that these comments apply to Turtle?

Editors option: No, concerns about the case sensitivity, or lack of case 
sensitivity do not effect Turtle. Turtle is very careful to avoid doing 
anything other then refer to RDF Concepts 1.1. The grammar allows for any 
case of language tag segments and specifically passes the tag along as a 
"unicode string" no attempt to normalize the language is made as part of 
the Turtle specification. That's up to the rest of the RDF stack. We 
chickened out.

The only change would be to examples in the Turtle if the WG does decide 
one way or the other.



On Mar 29, 2013, at 06:09, Ivan Herman <ivan@w3.org> wrote:

Hong Sun does not have the right credentials to send the mail to the WG 
mailing list, so I forward this to the comment list for processing and 

Hong Sun, thank you.


Begin forwarded message:

From: Hong Sun <hong.sun@agfa.com>
Subject: [Moderator Action] Language Tag Case Conflict (between RDF1.1 and 
Date: March 29, 2013 10:43:18 GMT+01:00
To: public-rdf-wg@w3.org

Dear All, 

I am working on processing text with language tag, but reading the RDF 1.1 
specification, I found there is a conflict in choosing the case for a 
language tag. 

In RDF1.1 
It is stated 
a non-empty language tag as defined by [BCP47]. The language tag must be 
well-formed according to section 2.2.9 of [BCP47], and must be normalized 
to lowercase. 
which is together with the following example: 
show:218 show:localName "Cette Série des Années Septante"@fr-be .  # 
literal with a region subtag 

But taking a look at BCP47 
http://tools.ietf.org/html/bcp47#section-2.2.9        , it states 
For example, one might use a tag such as "no-QQ", where 'QQ' 
   is one of a range of private use ISO 3166-1 codes to indicate an 
   otherwise undefined region. 

An even more clear recommendation is given in this document in 
All subtags, including extension and private 
   use subtags, use lowercase letters with two exceptions: two-letter 
   and four-letter subtags that neither appear at the start of the tag 
   nor occur after singletons.  Such two-letter subtags are all 
   uppercase (as in the tags "en-CA-x-ca" or "sgn-BE-FR") and four- 
   letter subtags are titlecase (as in the tag "az-Latn-x-latn"). 

In short, it seems that: 
according to RDF1.1, we should uses de-ch,   
in BCP47, it recommends to use de-CH, 
and meanwhile RDF1.1 also states language tag must be well-formed 
according to [BCP47]. 

So now there is a conflict, and which exactly should we use? 

In addition, in the other specifictions, Turtle does not care the case, 
while N3 now also use lower case for sub-tag, e.g. de-ch. 

# was: "[a-zA-Z][a-zA-Z0-9]*(-[a-zA-Z0-9]+)?"; 
langcode        cfg:matches          "[a-z]+(-[a-z0-9]+)*"; # 
                cfg:canStartWith         "a". 

Is it possible to treat the language tag as case-insensitive? As Andy 
Seaborne suggested in 


Kind Regards,

Hong Sun | Agfa HealthCare
Researcher | HE/Advanced Clinical Applications Research
T  +32 3444 8108

Click on link to read important disclaimer: 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Friday, 29 March 2013 15:51:23 UTC

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