data_rights link to VODataService is sort-of broken

[gpdf]

ObsCore's data_rights attribute is defined via reference to VODataService, for the values public, secure, and proprietary:

ObsCore/ObsCore.tex

Lines 1746 to 1748 in 6874912

	\subsubsection{Data Rights (data\_rights)}
	This parameter allows mentioning the availability of a dataset. Possible values are: public, secure, or proprietary as
	stated in the VODataService recommendation\citep{2010ivoa.spec.1202P}.

However, the relevant parts of VODataService were removed as part of the deprecation of DataCollection between v1.1 and v1.2 of VODataService:

ivoa-std/VODataService@66b7367

The inline reference in the text doesn't explicitly mention that it's v1.1 of VODataService, but the bibliographic references do:

Plante, Ray, and al. "VODataService : a VOResource schema extension for describing collections and services v 1.1."
http://www.ivoa.net/Documents/latest/VODataService/. IVOA Standards, 2010.

(except that the "latest" link is of course neither safe nor, at present, functional at all).

In the absence of data_rights it is possible to use a NULL or future value of obs_release_date to indicate that data are not freely available.

While the bibliographic link to VODataService v1.1 is (sort of, as noted above) correct, it seems weird to rely on a withdrawn part of that standard, so should future versions of ObsCore pull in the definitions for data_rights directly instead of by reference?

[msdemlei]

The obscore citation is wrong (but I don't think it's bad enough to warrant an erratum until we find a better way to fix the underlying issue).

What is referred to here is the rights element from VOResource. In version 1.03, this indeed had the three values mentioned in Obscore 1.1, B.4.4. But even in VOResource 1.1, we found that these three values were not really helpful, and we changed the content model to what it is now: In rights, you can have human-readable information on what you really want to happen ("cite X, acknowledge Y, don't re-publish, whatever“). And then there is rightsURI, which is supposed to be machine-readable. Since VOResource 1.2, we are now clear that we want SPDX licence URIs in there.

What does that mean for Obscore? Well, data_rights has not been used a lot. As a matter of fact:

select ivoid, table_name 
from rr.table_column 
natural join rr.res_table 
where name='data_rights'

(executed on a RegTAP service) says it's only in esasky at all, and there, it's not in an obscore table.

So, I'd say we can just change the thing to: “Give an SPDX URI here if you absolutely have to.“ I'd say that's material for an Erratum if we worry that someone will actually take that column up until Obscore 1.2.