Small question/suggestion re: ObsCore

[Markus Demleitner]

Hi DAL,

On Fri, Nov 09, 2018 at 12:22:06PM -0800, Gregory Dubois-Felsmann wrote:
> The ObsCore 1.1 standard, in Appendix C, Table 6, specifies the
> UCDs to be associated with ObsCore columns.  In particular, for
> s_ra and s_dec, it suggests pos.eq.ra and pos.eq.dec.  
> 
> [...]
> Was it considered, or would it be appropriate, for a service
> returning an ObsCore-compliant table (e.g., an SIAv2 or ObsTAP
> service) to be required (or strongly recommended) to include
> “meta.main” in the UCDs for “s_ra” and “s_dec”?

I'm not sure if it was considered, but it makes perfect sense to me.
It would, at the very least, help clients that don't know obscore or
don't now that a certain table is obscore make sense of the thing.

The trouble is: how would we get there?  Since validators check for
the unmodified pos.eq.* UCDs, a service that adds a ;meta.main will
become invalid.  An erratum proposing the addition would hence be
sort of hard to justify.  For a similar reason I'm not sure even an
Obscore 1.2 could introduce it -- although I doubt that at this point
there's code out there that would break.

So -- if someone finds a way to transition into having *;meta.main in
obscore, you'd have my support.  But I'm afraid I lack the
creativity...

          -- Markus