Request to register private-use variant subtags

CE Whitehead cewcathar at
Sat Apr 7 04:57:36 CEST 2012

Sorry for the delay in my response.
The codes reserved for private use for language, Script, region vary slightly: 
qaa - qtz: language
Qaaa - Qabx: script
QM-QZ (also AA, XA-XZ): region

Thus I do not know whether qxaaa - qx999999 would be the most appropriate choices.

Doug Ewell 
    doug at

    Sat Mar 31 01:51:14 CEST 2012
> I don't support this, and I believe the registration of a new 'begin..end' private-use block would require a revision of BCP 47.
I tend to concur with Doug, that rather than registering the whole set of gxaaa  - qx999999 variant codes, one would need to redo RFC 5646, and include the information about the new reserved codes in that document.

I am unsure as to whether a variant like qxqxqxqx or qzqzqzqz could be registered for this purpose.
The information from RFC 5646, starting with the second bullet, seems to say "no:"
"   o  Dialect or other divisions or variations within a language, its
      orthography, writing system, regional or historical usage,
      transliteration or other transformation, or distinguishing
      variation MAY be registered as variant subtags.  An example is the
      'rozaj' subtag (the Resian dialect of Slovenian).

"  o  The addition or maintenance of fields (generally of an
      informational nature) in tag or subtag records as described in
      Section 3.1 is allowed.  Such changes are subject to the stability
      provisions in Section 3.4.  This includes 'Description',
      'Comments', 'Deprecated', and 'Preferred-Value' fields for
      obsolete or withdrawn codes, or the addition of 'Suppress-Script'
      or 'Macrolanguage' fields to primary language subtags, as well as
      other changes permitted by this document, such as the addition of
      an appropriate 'Prefix' field to a variant subtag.

"  o  The addition of records and related field value changes necessary
      to reflect assignments made by ISO 639, ISO 15924, ISO 3166-1, and
      UN M.49 as described in Section 3.4 is allowed."

"   This document leaves the decision on what subtags or changes to
   subtags are appropriate (or not) to the registration process
   described in Section 3.5."
--C. E. Whitehead
cewcathar at 
 > Addison is correct: the only use case for this appears to be to solve a transitory programming problem. The -x- mechanism exists to solve the problem of encoding language variations that don't have a registered subtag.

> Private-use language, script, and region subtags (like 'qaa') weren't invented by or for BCP 47; they exist in the core standards (ISO 639, 3166, 15924) for applications that can't use the BCP 47 -x- mechanism.

> --
> Doug Ewell | Thornton, Colorado, USA
> | @DougEwell
> Sent via BlackBerry by AT&T\

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