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

Hi David,

These comments are made mainly on a contradictory in the RDF 1.1 
specification, where a conflict between RDF1.1 and BCP 47 is observed.

Meanwhile I am also observed that RDF1.1, N3 and Turtle have different 
requirements in representing the case of language tag, to this extent, it 
is also indirectly related with Turtle.


Kind Regards,

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

http://www.agfahealthcare.com
http://blog.agfahealthcare.com
Click on link to read important disclaimer: 
http://www.agfahealthcare.com/maildisclaimer 



From:   David Wood <david@3roundstones.com>
To:     Ivan Herman <ivan@w3.org>
Cc:     public-rdf-comments Comments <public-rdf-comments@w3.org>, Hong 
Sun/AXIFX/AGFA@AGFA
Date:   03/29/2013 04:13 PM
Subject:        Re: Language Tag Case Conflict (between RDF1.1 and BCP47)



Hi Hong Sun and Ivan,

Do I understand correctly that these comments apply to Turtle?

Regards,
Dave
--
http://about.me/david_wood



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 
archiving!

Hong Sun, thank you.

Ivan

Begin forwarded message:

From: Hong Sun <hong.sun@agfa.com>
Subject: [Moderator Action] Language Tag Case Conflict (between RDF1.1 and 
BCP47)
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 
http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/#dfn-language-tag 
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 
http://tools.ietf.org/html/bcp47#section-2.1.1 
""" 
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. 

http://www.w3.org/2000/10/swap/grammar/n3.n3 
""" 
# was: "[a-zA-Z][a-zA-Z0-9]*(-[a-zA-Z0-9]+)?"; 
langcode        cfg:matches          "[a-z]+(-[a-z0-9]+)*"; # 
http://www.w3.org/TR/rdf-testcases/#language 
                cfg:canStartWith         "a". 
""" 

Is it possible to treat the language tag as case-insensitive? As Andy 
Seaborne suggested in 
http://lists.w3.org/Archives/Public/public-rdf-wg/2013Feb/0275.html 

Thanks! 

Kind Regards,

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

http://www.agfahealthcare.com
http://blog.agfahealthcare.com
Click on link to read important disclaimer: 
http://www.agfahealthcare.com/maildisclaimer 


----
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