Versioned standardIDs for standard vocabularies? Also, including IVOA attributes in Avro schemas

[Dubois-Felsmann, Gregory P.]

I did look at "Vocabularies in the VO", v2.1, by the way, but it didn't seem to cover this directly.  The document says explicitly:

"UCDs are related to vocabularies in that they provide machine-readable semantics. Because the terms listed in the document can be combined and have an underlying grammar, however, they go beyond standard RDF. Hence, no attempt is being made to integrate them into the framework proposed here at this time. The UCD atoms might be organised in an RDF vocabulary, though, and doing so might be considered in the future."

and it has nothing to say about units.

I think this is, as noted in the quote above, because neither UCDs nor units are "flat" vocabularies, given that the standards also include rules for combining them into complex expressions.

Again, though, I'm not up to speed on the history of this line of work.

Gregory