Review language-related guidanced in bp-i18n-specdev

[aphillips]

Need to review the language-related guidance in specdev.

• In some cases we need to copy guidelines into LTLI.
• In some cases we need to resolve duplicates with LTLI.
• In some cases we should revisit guidance.

Once LTLI is through it's wide review we'll need to do the reverse and put guidelines into specdev, so we should lay groundwork now.

[xfq]

Agreed. Should we also review the locale-related guidance?

[xfq]

Took a brief look at these two documents:

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[From LTLI] Formulations such as "RFC 5646 or its successor" MAY be used, but only in cases where the specific document version is necessary.

This guideline is not covered in specdev.

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[From LTLI] Specifications that need to preserve compatibility with obsolete versions of [BCP47] MUST reference the production obs-language-tag in [BCP47].

This guideline is not covered in specdev.

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[From LTLI] Content validators SHOULD check if content uses valid language tags where feasible.

This guideline is not covered in specdev.

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[From LTLI] Specifications SHOULD NOT reference [BCP47]'s underlying standards that contribute to the IANA Language Subtag Registry, such as ISO639, ISO15924, ISO3066, or UN M.49.

This guideline is not covered in specdev.

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[From LTLI] Applications that provide language information as part of URIs (e.g. in the realm of RDF) SHOULD use [BCP47].

This guideline is not covered in specdev.

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[From LTLI] Specifications SHOULD NOT restrict the length of language tags or permit or encourage the removal of extensions.

This guideline is not covered in specdev.

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[From specdev] Refer to BCP 47, not to RFC 5646.

Should it mention RFC 1766 and RFC 3066, like LTLI?

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In addition, the following guidance are in LTLI but not in specdev:

• Unicode locale related guidelines
• language tag matching related guidelines