Fwd: Information about latest specs for language tagging

Editors, All - FYI, some information from the I18N group re normative  
reference for language tags.

Begin forwarded message:

> From: ext Richard Ishida <ishida@w3.org>
> Date: March 1, 2010 9:53:20 AM EST
> Subject: Information about latest specs for language tagging
>
> It seems that a number of people are unaware of recent changes with  
> regards to language tagging specifications. As it is important to  
> use the right reference for spec development, I hope the following  
> information will prove useful.
>
> You used to specify a language tag using RFC 1766, and then RFC  
> 3066, both of which referred you to a list of ISO codes for  
> language subtags and another ISO list for country names.
>
> RFC 3066 was replaced by two RFCs:  4646 (Tags for Identifying  
> Languages) and 4647 (Matching of Language Tags).  These two RFCs  
> were concatenated at a single location under the name BCP 47. It is  
> intended that BCP 47 will be an unchanging name with a single,  
> unchanging URI that gives access to the most up-to-date RFCs as  
> they are developed.  This is particularly helpful since it is not  
> clear from reading RFC the itself that it has been obsoleted.
>
> In September 2009, RFC 4646 was obsoleted by RFC 5646 (but RFC 4647  
> remains current).  RFCs 5646 and 4647 are still referred to as BCP  
> 47, and BCP 47 is accessed via the same URI as before.
>
> The latest specifications for language tagging allow a number of  
> different types of subtag, over and above language and country/ 
> region, and point you to the IANA Language Subtag Registry (rather  
> than ISO code lists) to find the (almost 8,000) subtags which are  
> now available for use.
>
> Any language tags constructed using the obsoleted RFCs are still  
> valid according to the syntax of the latest incarnation of BCP 47,  
> though some tags are now deprecated.
>
>
> We recommend that you currently use the following reference for  
> language tag syntax.
> [BCP47]
>     Tags for Identifying Languages, A. Phillips and M. Davis,  
> Editors, September 2009.
>     Available at http://www.rfc-editor.org/rfc/bcp/bcp47.txt
>
> The following additional links may be useful for further reading:
> IANA Language Subtag Registry		http://www.iana.org/assignments/ 
> language-subtag-registry
> Language tags in HTML and XML	http://www.w3.org/International/ 
> articles/language-tags/
> Choosing a Language Tag		http://www.w3.org/International/questions/ 
> qa-choosing-language-tags
> Language Subtag Lookup tool		http://rishida.net/utils/subtags/
>
> If you have further questions about language tags, please contact  
> the i18n WG.
>
> Hope that helps,
> RI
>
> ============
> Richard Ishida
> Internationalization Lead
> W3C (World Wide Web Consortium)
>
> http://www.w3.org/International/
> http://rishida.net/