Region subtags and orthographic variants (was: Re: registration requests re Portuguese)

[Yury]

On 04/16/2015 01:26 PM, Doug Ewell wrote:
> Yury <yury dot tarasievich at gmail dot com> wrote:
>
>>>> pt-ao1990-PT
>>>
>>> Syntactically that is impossible for language tags. The ordering must
>>> be as specified in https://tools.ietf.org/html/bcp47#section-2.1.
>>
>> How so? Oh wait, section 2.2.4 rule 1, overriding the ABNF spec in the
>> same document, which, as it turns out, is just for show.
>> Who writes specifications like this, anyway?.. Ah.
>
> I don't see the conflict that Yury is seeing.

After Mark's post, I re-browsed the RFC beyond the ABNF and section 3.
Rule 2.2.4.1 can be understood as either (1) "the order of use of 
'language' and 'region' must be 'language', then 'region'" or (2) "there 
must always be 'region' after 'language'". First is completely redundant 
(by ABNF) and not corroborating Mark's post, so second must be it -- 
Mark claims so, and he is the rfc5646 author, after all. But then it 
overrides the rfc5646 ABNF with region being optional (square brackets 
rule, rfc5234#3.8).

-Yury