Are any tags valid as literal language tags?

Hi,

Document "Resource Description Framework (RDF): Concepts and Abstract
Syntax" from 2004:
https://www.w3.org/TR/2004/REC-rdf-concepts-20040210

In section 6.5 says "Plain literals have a lexical form and optionally
a language tag as defined by [RFC-3066], normalized to lowercase."

Here's a copy of RFC-3066:
https://www.ietf.org/rfc/rfc3066.txt

In Section 2.2 "Language tag sources", it says:

"All 2-letter subtags are interpreted according to assignments found
in ISO standard 639, "Code for the representation of names of
languages" [ISO 639]"

And here are the list of ISO-639-1 codes:
https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes

Does that mean that RDF language literals that have language tags not
in that list is invalid?

E.g. "Foo@en" is a valid language literal node, whereas "Foo@zz" is an
invalid language literal node?

Thanks,

--
Rob

Received on Thursday, 17 November 2016 10:31:31 UTC