Question on language tags and directionality metadata

Dear Ontolex community,

recently I asked Gerard de Melo a question on language tags and
directionality, see below. I know that this topic is not directly of
concern for OntoLex, but maybe you have some thoughts on this or an idea
who else to talk to? Thanks a lot for any feedback in advance.

Best,

Felix

---------- Forwarded message ---------
From: Felix Sasaki <felix@sasakiatcf.com>
Date: Fri, 3 Apr 2020 at 17:15
Subject: Question on Lexvo and language tags and directionality metadata
To: Gerard de Melo <gdm@demelo.org>
Cc: <felix.sasaki@th-brandenburg.de>


Dear Gerard,

I hope you are doing well - this is Felix Sasaki, we have been in contact
in RDF & multilingual related topics a while ago.

I am still involved in W3C, in the internationalization activity. Here
recently a question came up on BCP 47, the IETF standard for language tags
including the related sub tag registry, and RDF approaches to
represent information about language.

In RDF, of course you can use BCP 47 language tags for literals, but there
are valuable resources like Lexvo that identify languages via URIs. Often
these resources are based on ISO standards and have no direct relation to
BCP 47. This leads also to fragmentation, for example since BCP 47 includes
sub tags that are not part of a given ISO standard for languages or regions.

In this context, I have a few questions:

1) Do you know of any best practices & use cases for using URIs (from Lexvo
or other sources) in an RDF context? By "using" I mean using the URIs to
identify the language of a (sub part of an) RDF graph.

2) Are there any recommendations like: "here use URIs, here use BCP 47"?
For what I found, the main use case of URIs to express information *about*
languages as first-class objects, but not to attach language information to
other parts of an RDF graph - see 1) above.

3) In addition to language, there is other type of metadata needed in an
i18n context, e.g. metadata about directionality of strings. Do you now
about best practices for representing such metadata in RDF?

4) In an "identify language via URIs" approach, how would one identify the
entries of the BCP 47 sub tag registry that do no have an URI?

5) Is there an authority for language related URIs?

Thanks a lot for your feedback in advance & best regards,

Felix