Private Use Variant Subtag

[Phillips, Addison]

Hi Gordon,

What would the use case be for such a tag, other than for writing unit tests? It's inappropriate for interchange. I don't see the point in creating a subtag specifically to mean "nothing".

For my code, I have a copy of the registry (which is used for validity checks, using the BCP47 definition of "valid") and I have unit tests for "well-formed" tags that check all of the possible values. 

You can, of course, propose a registration. I just think such a tag is rather unlikely to gain acceptance, since it doesn't identify any actually language variation. If memory serves, the idea of private use was raised during the incubation of the current RFCs, but was rejected simply because we have an -x- separated ocean of private use in the position immediately following any (valid) variants and this is the preferred private use mechanism.

Addison

> -----Original Message-----
> From: Gordon P. Hemsley [mailto:gphemsley at gmail.com]
> Sent: Friday, March 30, 2012 1:41 PM
> To: Phillips, Addison
> Cc: Philip Newton; Mark Davis ☕; ietf-languages at iana.org
> Subject: Re: Private Use Variant Subtag
> 
> Addison,
> 
> My chosen variant subtag was 'qaaaaaaz', to match some of the other private
> use subtags. But given that it was potentially registerable, I wanted to see if
> there was a better way. (Would it be possible to file a registration for a "Private
> use" variant subtag?)
> 
> Thanks,
> Gordon
> 
> On Fri, Mar 30, 2012 at 4:32 PM, Phillips, Addison <addison at lab126.com>
> wrote:
> > There is no variant subtag that is "guaranteed" to be unassigned and yet still
> be syntactically valid.
> >
> > Unlike the subtags based on external standards, BCP 47 didn't reserve any
> variant subtags for private use (because such a usage is superfluous: we have a
> panoply of private use mechanisms). If you want to test something, it is useful
> to note that most of subtags registered are at least vaguely mnemonic. A
> subtag like "qxqxqxqx" is a pretty good bet.
> >
> > Addison
> >
> >> -----Original Message-----
> >> From: ietf-languages-bounces at alvestrand.no [mailto:ietf-languages-
> >> bounces at alvestrand.no] On Behalf Of Gordon P. Hemsley
> >> Sent: Friday, March 30, 2012 1:20 PM
> >> To: Philip Newton; Mark Davis ☕
> >> Cc: ietf-languages at iana.org
> >> Subject: Re: Private Use Variant Subtag
> >>
> >> Mark, Phillip,
> >>
> >> Perhaps I wasn't clear. I'm not looking for alternatives to variant
> >> tags. I'm well aware of the -x- private use singleton.
> >>
> >> What I need is a variant tag that is guaranteed to be unassigned. One
> >> that matches the definition exactly:
> >>
> >>  variant       = 5*8alphanum         ; registered variants
> >>                / (DIGIT 3alphanum)
> >>
> >> Using -x- does not solve my problem.
> >>
> >> Regards,
> >> Gordon
> >>
> >> On Fri, Mar 30, 2012 at 12:58 PM, Philip Newton
> >> <philip.newton at gmail.com>
> >> wrote:
> >> > On Fri, Mar 30, 2012 at 18:56, Philip Newton
> >> > <philip.newton at gmail.com>
> >> wrote:
> >> >> I must admit I'm a bit puzzled at the OP's claim that "there do
> >> >> not appear to be any variant subtags set aside for private use"
> >> >
> >> > ...and I failed to see that the OP specifically talked about
> >> > _variant_ subtags. Apologies.
> >> >
> >> > In which case -x- is what I would have thought of, too.
> >> >
> >> > Cheers,
> >> > Philip
> >> > --
> >> > Philip Newton <philip.newton at gmail.com>
> >> > _______________________________________________
> >> > Ietf-languages mailing list
> >> > Ietf-languages at alvestrand.no
> >> > http://www.alvestrand.no/mailman/listinfo/ietf-languages
> >>
> >>
> >>
> >> --
> >> Gordon P. Hemsley
> >> me at gphemsley.org
> >> http://gphemsley.org/ • http://gphemsley.org/blog/
> >> _______________________________________________
> >> Ietf-languages mailing list
> >> Ietf-languages at alvestrand.no
> >> http://www.alvestrand.no/mailman/listinfo/ietf-languages
> 
> 
> 
> --
> Gordon P. Hemsley
> me at gphemsley.org
> http://gphemsley.org/ • http://gphemsley.org/blog/