additions to ISO 639 and the IANA language subtag registry

[Peter Constable]

What exactly in RFC3066bis requires that every lang ID added to ISO 639 must be included in the language subtag registry? (I’m talking about additions, not the initial registry.)

Section 3.3 says that the reviewer

- “MUST evaluate each change, determine whether it conflicts with existing registry entries, and submit the information to IANA for inclusion in the registry” 

- "MUST ensure that new subtags meet the requirements in Section 4.1 (Choice of Language Tag) or submit an appropriate alternate subtag as described in that section"


Re the first point, the role of evaluation suggests the option to make some decision about the impact of the change wrt the registry. The text might be read to mean that the reviewer can decide not to add a new ISO 639 ID to the registry in the particular case that the ID conflicts with an existing subtag, though that's vague, as is the criteria for "conflicts".

I don't have any specific case in mind of an ISO 639 ID that I think should not be added to the subtag registry (though in general I'm inclined to discourage the use of language-collection IDs); I'm just trying to understand what the operation principles are here.


Peter Constable